180 results on '"Tomáš Grim"'
Search Results
2. Bird tolerance to humans in open tropical ecosystems
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Peter Mikula, Oldřich Tomášek, Dušan Romportl, Timothy K. Aikins, Jorge E. Avendaño, Bukola D. A. Braimoh-Azaki, Adams Chaskda, Will Cresswell, Susan J. Cunningham, Svein Dale, Gabriela R. Favoretto, Kelvin S. Floyd, Hayley Glover, Tomáš Grim, Dominic A. W. Henry, Tomas Holmern, Martin Hromada, Soladoye B. Iwajomo, Amanda Lilleyman, Flora J. Magige, Rowan O. Martin, Marina F. de A. Maximiano, Eric D. Nana, Emmanuel Ncube, Henry Ndaimani, Emma Nelson, Johann H. van Niekerk, Carina Pienaar, Augusto J. Piratelli, Penny Pistorius, Anna Radkovic, Chevonne Reynolds, Eivin Røskaft, Griffin K. Shanungu, Paulo R. Siqueira, Tawanda Tarakini, Nattaly Tejeiro-Mahecha, Michelle L. Thompson, Wanyoike Wamiti, Mark Wilson, Donovan R. C. Tye, Nicholas D. Tye, Aki Vehtari, Piotr Tryjanowski, Michael A. Weston, Daniel T. Blumstein, and Tomáš Albrecht
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Science - Abstract
Abstract Animal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.
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- 2023
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3. Hope for Bohemian ecologists – comments on 'A possible role of social activity to explain differences in publication output among ecologists?' by Tomáš Grim, Oikos 2008
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Douglas Sheil, S. Wunder, Patrick A. Jansen, R. Dudley, and Frans Bongers
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Czech ,lcsh:QH1-199.5 ,media_common.quotation_subject ,lcsh:QR1-502 ,lcsh:QH1-278.5 ,Consumption (sociology) ,Sister ,lcsh:General. Including nature conservation, geographical distribution ,lcsh:Microbiology ,lcsh:Physiology ,Neglect ,lcsh:Oceanography ,Duration (philosophy) ,lcsh:QH540-549.5 ,lcsh:Botany ,lcsh:Zoology ,lcsh:GC1-1581 ,lcsh:QL1-991 ,lcsh:Human ecology. Anthropogeography ,lcsh:Science ,lcsh:QH301-705.5 ,Ecology, Evolution, Behavior and Systematics ,lcsh:Environmental sciences ,media_common ,lcsh:GE1-350 ,Ecology ,biology ,lcsh:QP1-981 ,Social activity ,lcsh:Natural history (General) ,Miller ,biology.organism_classification ,language.human_language ,lcsh:QK1-989 ,Variation (linguistics) ,lcsh:Biology (General) ,language ,lcsh:Q ,lcsh:Ecology ,lcsh:GF1-900 - Abstract
and elsewhere. A lighter prose is encouraged and no summary is required. Formal research papers, however short, will not be considered.Like many ecologists we were intrigued by Tomas Grim’s original and thought-provoking evaluation of professional achievement amongst his Bohemian ecologist colleagues in your sister journal, Oikos (Grim 2008). In his paper, Grim argues and infers from a correlational analysis that publication success is negatively affected by beer drinking – an assumed correlate of ‘social activity’ – due to nega -tive effects of alcohol on cognitive performance. Here we question Grim’s conclusions. We criticize his focus on a single hypothesis, without consideration of reasonable al-ternatives, and note that his approach provides a valuable illustration of a more general flaw in ecological inference.Grim correlated publication success of Czech ecologists to their self-reported beer consumption. We note short-falls in this approach. We could, for example, quibble with Grim’s measures of publication success (Lortie et al. 2007), note the problems of using self-reported drinking as a measure of true alcohol consumption (Nevitt and Lundak 2005), question his neglect of gender differences (Bailly et al. 1991) and debate whether heavier drinkers really are involved in more social or anti-social behaviour (Ogle and Miller 2004). We might also note the paper focuses on just 10% of the variation in publication success – that part not explained by each ecologist’s age and duration of publica -tion career. However, this would be nit-picking. Our main concern is with Grim’s pessimism-by-default regarding the impending obscurity of drinking ecologists. As we justify below, there are good reasons to be more optimistic.
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- 2008
4. Are birds reliable indicators of most valuable natural areas? Evaluation of special protection areas in the context of habitat protection
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Petr Kovařík, Vilém Pechanec, Ivo Machar, Jaromír Harmáček, and Tomáš Grim
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Birds ,Habitats ,Indicators ,Territorial protection ,Natura 2000 ,Special protection areas ,Ecology ,QH540-549.5 - Abstract
Territorial protection of nature in any country is limited by various factors and therefore it is necessary to carefully select protected areas. Currently, they are often selected according to particular indicator taxa because of the simplicity and applicability of this approach. For example, Natura 2000 Special Protection Areas (SPAs) in EU are established to protect selected species of birds. We asked how well do SPAs cover valuable natural habitats, i.e., whether the areas selected for the protection of birds are also important for the conservation of natural habitats. We focused on the Czech Republic because detailed data on habitat composition are available for the whole country. Although SPAs covered only 9% of the whole country they contained disproportionately high part of the whole area of preserved natural habitats (36%). This was because 64% of SPAs area was covered by natural habitats compared to only 11% in the rest of the country. However, the importance of SPAs for different habitats and their formation groups varied significantly. Further, we found a positive relationship between habitat rareness and the proportion of rare habitats within SPAs. Despite their relatively small overall area SPAs host disproportionally large areas of natural habitats in the Czech Republic. This pattern suggests that birds are reliable indicators for territorial protection. SPAs thus show large importance for habitat conservation.
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- 2021
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5. Hope for Bohemian ecologists – comments on “A possible role of social activity to explain differences in publication output among ecologists?” by Tomáš Grim, Oikos 2008
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Sheil, D., primary, Wunder, S., additional, Jansen, P., additional, Bongers, F., additional, and Dudley, R., additional
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- 2008
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6. Author Correction: Effects of climate variation on bird escape distances modulate community responses to global change
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Gábor Markó, Federico Morelli, Manuel A. Diaz, Anders Pape Møller, Jukka Jokimäki, J. D. Ibáñez‑Alamo, Piotr Tryjanowski, Kai Tätte, Tomáš Grim, and M.‑L. Kaisanlahti‑Jokimäki
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Multidisciplinary ,Geography ,Climatology ,Science ,Medicine ,Climate variation ,Global change - Published
- 2021
7. First-Time Migration in Juvenile Common Cuckoos Documented by Satellite Tracking.
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Marta Lomas Vega, Mikkel Willemoes, Robert L Thomson, Jere Tolvanen, Jarkko Rutila, Peter Samaš, Roine Strandberg, Tomáš Grim, Frode Fossøy, Bård Gunnar Stokke, and Kasper Thorup
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Medicine ,Science - Abstract
Being an obligate parasite, juvenile common cuckoos Cuculus canorus are thought to reach their African wintering grounds from Palearctic breeding grounds without guidance from experienced conspecifics but this has not been documented. We used satellite tracking to study naïve migrating common cuckoos. Juvenile cuckoos left breeding sites in Finland moving slowly and less consistently directed than adult cuckoos. Migration of the juveniles (N = 5) was initiated later than adults (N = 20), was directed toward the southwest-significantly different from the initial southeast direction of adults-and included strikingly long Baltic Sea crossings (N = 3). After initial migration of juvenile cuckoos toward Poland, the migration direction changed and proceeded due south, directly toward the winter grounds, as revealed by a single tag transmitting until arrival in Northwest Angola where northern adult cuckoos regularly winter. Compared to adults, the juvenile travelled straighter and faster, potentially correcting for wind drift along the route. That both migration route and timing differed from adults indicates that juvenile cuckoos are able to reach proper wintering grounds independently, guided only by their innate migration programme.
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- 2016
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8. Nature's Palette: Characterization of Shared Pigments in Colorful Avian and Mollusk Shells.
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Aida Verdes, Wooyoung Cho, Marouf Hossain, Patricia L R Brennan, Daniel Hanley, Tomáš Grim, Mark E Hauber, and Mandë Holford
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Medicine ,Science - Abstract
Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature's palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa.
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- 2015
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9. Effects of climate variation on bird escape distances modulate community responses to global change
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Kunter Tätte, Federico Morelli, Anders Pape Møller, Piotr Tryjanowski, Tomáš Grim, Juan Diego Ibáñez-Álamo, Gábor Markó, Manuel A. Diaz, Marja-Liisa Kaisanlahti-Jokimäki, Jukka Jokimäki, Ministry of Innovation and Technology (Hungary), Ministry of Education and Research (Estonia), Agencia Estatal de Investigación (España), and Ministerio de Ciencia e Innovación (España)
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0106 biological sciences ,0301 basic medicine ,Climate ,Climate Change ,Ecology (disciplines) ,media_common.quotation_subject ,Science ,Population Dynamics ,Public administration ,010603 evolutionary biology ,01 natural sciences ,Article ,Birds ,03 medical and health sciences ,Excellence ,Agency (sociology) ,Animals ,Humans ,Climate variation ,Author Correction ,media_common ,Multidisciplinary ,Geography ,Ecology ,Global change ,Estonian ,Readability ,language.human_language ,Environmental sciences ,030104 developmental biology ,Institutional research ,language ,Medicine ,Animal Migration ,Zoology ,Climate sciences - Abstract
Warm thanks to Jacqui Sykoff for substantially improving the readability of former versions of the manuscript. GM was supported by the Hungarian Ministry for Innovation and Technology within the framework of the Thematic Excellence Programme 2020 (TKP2020-IKA-12, TKP2020-NKA-16).. KT was supported by institutional research funding IUT (34-8) of the Estonian Ministry of Education and Research. This paper is a contribution to the project URBILAND (PID2019-107423GA-I00/SRA 1013039/501100011033), funded by the Spanish Research Agency., Climate and land use are rapidly changing environmental conditions. Behavioral responses to such global perturbations can be used to incorporate interspecific interactions into predictive models of population responses to global change. Flight initiation distance (FID) reflects antipredator behaviour defined as the distance at which an individual takes flight when approached by a human, under standardized conditions. This behavioural trait results from a balance between disturbance, predation risk, food availability and physiological needs, and it is related to geographical range and population trends in European birds. Using 32,145 records of flight initiation distances for 229 bird species during 2006-2019 in 24 European localities, we show that FIDs decreased with increasing temperature and precipitation, as expected if foraging success decreased under warm and humid conditions. Trends were further altered by latitude, urbanisation and body mass, as expected if climate effects on FIDs were mediated by food abundance and need, differing according to position in food webs, supporting foraging models. This provides evidence for a role of behavioural responses within food webs on how bird populations and communities are affected by global change., Hungarian Ministry for Innovation and Technology TKP2020-IKA-12 TKP2020-NKA-16, Ministry of Education and Research, Estonia 34-8, Spanish Research Agency PID2019-107423GA-I00/SRA 1013039/501100011033
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- 2021
10. White stork nest altitude decreases as global temperatures increase
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Daniel Hanley, Markéta Nyklová-Ondrová, and Tomáš Grim
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0106 biological sciences ,0301 basic medicine ,Ciconia ,Climate change ,Plant Science ,01 natural sciences ,Biochemistry ,03 medical and health sciences ,Altitude ,Nest ,biology.animal ,Genetics ,Molecular Biology ,Ecology, Evolution, Behavior and Systematics ,White stork ,biology ,Land use ,Ecology ,Global warming ,Cell Biology ,biology.organism_classification ,030104 developmental biology ,Geography ,Animal Science and Zoology ,Arable land ,010606 plant biology & botany - Abstract
Climate change causes altitudinal shifts of animal distributions and this effect can potentially be accentuated or altered due to human agricultural activities. Because of the availability of uniquely long-term monitoring data, we chose the white stork (Ciconia ciconia) as a model species. We analyzed large data sets (record cards from 1191 nests) covering the long-term period from 1875 to 2005 in the Czech Republic, central Europe. We analyzed nest altitude during years of founding of the nest, temperature, land use variables and types of nests (natural vs. human provided nest pads). Consistent with findings from previous studies we predicted a temporal increase in the altitude of white stork nests. Surprisingly, we found that the altitude of nests was decreasing, despite an increase in local mean spring temperatures. The altitude of nests was higher when the proportion of arable land, water areas and developed land was lower and when the proportion of grass and forest cover was greater. The decrease in altitude was significant in natural nests (built by storks) but non-significant in nests on nest platforms (built by humans). Thus, human agricultural activities might potentially override the opposing effects of global climate change on animal altitudinal distribution shifts.
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- 2019
11. Host Responses to Foreign Eggs across the Avian Visual Color Space
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Daniel Hanley, Mark E. Hauber, Karel Gern, and Tomáš Grim
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0106 biological sciences ,Color vision ,media_common.quotation_subject ,Color ,Sensory system ,Color space ,Biology ,010603 evolutionary biology ,01 natural sciences ,Nesting Behavior ,03 medical and health sciences ,Perception ,Animals ,Passeriformes ,reproductive and urinary physiology ,Ecology, Evolution, Behavior and Systematics ,Ovum ,030304 developmental biology ,media_common ,Brood parasite ,0303 health sciences ,Communication ,Pigmentation ,Host (biology) ,business.industry ,European blackbird ,Cognition ,behavior and behavior mechanisms ,Female ,business ,Color Perception - Abstract
Despite extensive research on the sensory and cognitive processes of host rejection of avian brood parasites' eggs, the underlying perceptual and cognitive mechanisms are not sufficiently understood. Historically, most studies of host egg discrimination assumed that hosts rejected a parasite's egg from their nest based on the perceived color and pattern differences between the parasite's egg and their own. A recent study used a continuous range of parasitic egg colors and discovered that hosts were more likely to reject browner foreign eggs than foreign eggs that were more blue green, even when their absolute perceived color differences from the hosts' own egg colors were similar. However, the extent of these color biases across the avian perceivable color space remains unclear. Therefore, we built on this previous study by testing European blackbirds' (
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- 2019
12. Contagious fear
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Juan Diego Ibáñez-Álamo, Tomáš Grim, Mario Díaz, Federico Morelli, Marja-Liisa Kaisanlahti-Jokimäki, Kunter Tätte, Anders Pape Møller, Piotr Tryjanowski, Gábor Markó, Yanina Benedetti, Jukka Jokimäki, Yiting Jiang, Eötvös Loránd University, Ministry of Education and Research (Estonia), Czech Science Foundation, Tieleman lab, Czech University of Life Sciences Prague (CZU), Museo Nacional de Ciencias Naturales [Madrid] (MNCN), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Palacky University Olomouc, University of Groningen [Groningen], University of Lapland, University of Tartu, Hungarian Natural History Museum (Magyar Természettudományi Múzeum), Eötvös Loránd University (ELTE), Ecologie Systématique et Evolution (ESE), Université Paris-Sud - Paris 11 (UP11)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Institute of Zoology, and Poznan University of Life Sciences
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0106 biological sciences ,LIFE-HISTORY ,Zoology ,Biology ,URBAN ,Affect (psychology) ,010603 evolutionary biology ,01 natural sciences ,gregariousness ,Predation ,human disturbance ,03 medical and health sciences ,RESPONSE DISTANCES ,lcsh:QH540-549.5 ,vigilance ,[SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology ,dilution effect ,FID ,DISTURBANCE ,ADAPTATION ,Predator ,Ecology, Evolution, Behavior and Systematics ,Sociality ,030304 developmental biology ,Nature and Landscape Conservation ,Original Research ,RISK ,0303 health sciences ,fear response ,PREDATION ,Ecology ,4. Education ,EVOLUTION ,Vigilance (behavioural ecology) ,Habitat ,birds ,FLIGHT-INITIATION DISTANCE ,social interactions ,Flock ,lcsh:Ecology ,Adaptation ,[SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis - Abstract
Flight initiation distance (FID), the distance at which individuals take flight when approached by a potential (human) predator, is a tool for understanding predator–prey interactions. Among the factors affecting FID, tests of effects of group size (i.e., number of potential prey) on FID have yielded contrasting results. Group size or flock size could either affect FID negatively (i.e., the dilution effect caused by the presence of many individuals) or positively (i.e., increased vigilance due to more eyes scanning for predators). These effects may be associated with gregarious species, because such species should be better adapted to exploiting information from other individuals in the group than nongregarious species. Sociality may explain why earlier findings on group size versus FID have yielded different conclusions. Here, we analyzed how flock size affected bird FID in eight European countries. A phylogenetic generalized least square regression model was used to investigate changes in escape behavior of bird species in relation to number of individuals in the flock, starting distance, diet, latitude, and type of habitat. Flock size of different bird species influenced how species responded to perceived threats. We found that gregarious birds reacted to a potential predator earlier (longer FID) when aggregated in large flocks. These results support a higher vigilance arising from many eyes scanning in birds, suggesting that sociality may be a key factor in the evolution of antipredator behavior both in urban and rural areas. Finally, future studies comparing FID must pay explicit attention to the number of individuals in flocks of gregarious species., Higher Education Institutional Excellence Program, Grant/Award Number: 1783‐3/2018/FEKUTSTRAT; Estonian Ministry of Education and Research, Grant/Award Number: 34‐8; Czech Science Foundation GAČR, Grant/Award Number: 18‐16738S
- Published
- 2019
13. Post‐fledging interactions between the Common Cuckoo Cuculus canorus and its cavity‐nesting Common Redstart Phoenicurus phoenicurus host
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Peter Samaš, Michal Kysučan, and Tomáš Grim
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0106 biological sciences ,Brood parasite ,Fledge ,Zoology ,Biology ,Redstart ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Brood ,Cuculus ,010605 ornithology ,Common cuckoo ,Phoenicurus phoenicurus ,Animal Science and Zoology ,Cuckoo ,Ecology, Evolution, Behavior and Systematics - Abstract
Brood parasite–host interactions during the incubation and nestling stages have been well studied, but the post‐fledging period remains virtually unknown. Using radiotracking, we provide the first detailed data on post‐fledging interactions between the Common Cuckoo Cuculus canorus and its only regular cavity‐nesting host, the Common Redstart Phoenicurus phoenicurus. Cuckoos raised alone (‘solitary’) fledged at higher mass, with higher wing and tarsus length and started to fly at a younger age than Cuckoos raised alongside young Redstarts (‘mixed’). However, a further 23 fledging and post‐fledging parameters measured at five pre‐determined times (fledging, first‐flight, predation, starvation, independence) did not differ between solitary and mixed Cuckoos. In addition, none of the parameters measured during the post‐fledging period (growth, dispersal distances, number of flights) differed between solitary and mixed Cuckoos. Redstart fledglings from non‐parasitized broods (‘solitary’) showed generally similar fledging and post‐fledging parameters to fledglings reared alongside a Cuckoo (‘mixed’). Surprisingly, there were no significant differences in post‐fledging predation rate, starvation or overall survival rates between mixed and solitary Cuckoos or mixed and solitary Redstarts. Thus, during the post‐fledging period, mixed Cuckoo fledglings successfully compensated for the poorer performance experienced during the nestling stage whereas mixed and solitary Redstarts did not differ in any measured parameters. This suggests that the regular occurrence of mixed broods in this host–parasite system – which is unique among the many Cuckoo hosts – is evolutionarily stable for both hosts and parasites.
- Published
- 2019
14. No immediate or future extra costs of raising a virulent brood parasite chick
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Tomáš Grim, Marcel Honza, Michal Šulc, Peter Samaš, Václav Jelínek, and Marek M Abraham
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0106 biological sciences ,Brood parasite ,0303 health sciences ,Virulence ,Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,Raising (linguistics) ,03 medical and health sciences ,Animal Science and Zoology ,health care economics and organizations ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology - Abstract
Parental care is an adaptive behavior increasing the survival of a young. Virulent brood parasites, like the common cuckoo Cuculus canorus, avoid the parental care and leave the care for their nestlings to hosts. Although raising a cuckoo is always costly because it kills host’s progeny, to date it is not known whether raising of a brood parasite itself represents any extra cost affecting host’s fitness, that is, a cost above the baseline levels of care that are expended on raising the host own young anyway. We quantified costs of rearing a cuckoo nestling in the most frequent host, the reed warbler Acrocephalus scirpaceus. We measured changes in the host physical (body mass) and physiological conditions (stress levels quantified via heterophils/lymphocytes ratio) within the 1 breeding attempt (immediate cost) and retrapped some of these adults in the next breeding season to estimate return rates as a measure of their survival (future cost). In contrast to universal claims in the literature, raising a cuckoo nestling did not entail any extra immediate or future costs for hosts above natural costs of care for own offsprings. This counterintuitive result might partly reconcile theoretical expectations in the hosts with surprisingly low levels of counter-defences, including the reed warbler. Unexpectedly low raising costs of parasitism may also help explain a long-term maintenance of some host–parasite systems.
- Published
- 2019
15. The geography of fear: a latitudinal gradient in anti-predator escape distances of birds across Europe.
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Mario Díaz, Anders Pape Møller, Einar Flensted-Jensen, Tomáš Grim, Juan Diego Ibáñez-Álamo, Jukka Jokimäki, Gábor Markó, and Piotr Tryjanowski
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Medicine ,Science - Abstract
All animals flee from potential predators, and the distance at which this happens is optimized so the benefits from staying are balanced against the costs of flight. Because predator diversity and abundance decreases with increasing latitude, and differs between rural and urban areas, we should expect escape distance when a predator approached the individual to decrease with latitude and depend on urbanization. We measured the distance at which individual birds fled (flight initiation distance, FID, which represents a reliable and previously validated surrogate measure of response to predation risk) following a standardized protocol in nine pairs of rural and urban sites along a ca. 3000 km gradient from Southern Spain to Northern Finland during the breeding seasons 2009-2010. Raptor abundance was estimated by means of standard point counts at the same sites where FID information was recorded. Data on body mass and phylogenetic relationships among bird species sampled were extracted from the literature. An analysis of 12,495 flight distances of 714 populations of 159 species showed that mean FID decreased with increasing latitude after accounting for body size and phylogenetic effects. This decrease was paralleled by a similar cline in an index of the abundance of raptors. Urban populations had consistently shorter FIDs, supporting previous findings. The difference between rural and urban habitats decreased with increasing latitude, also paralleling raptor abundance trends. Overall, the latitudinal gradient in bird fear was explained by raptor abundance gradients, with additional small effects of latitude and intermediate effects of habitat. This study provides the first empirical documentation of a latitudinal trend in anti-predator behavior, which correlated positively with a similar trend in the abundance of predators.
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- 2013
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16. Host dispersal shapes the population structure of a tick-borne bacterial pathogen
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Pedro Araújo, Michaela Hau, Rafael Barrientos, Markéta Nováková, Barbara Flaisz, Jennifer Morinay, Gabriele Margos, Volker Fingerle, János Török, Anastasia Diakou, Marcel E. Visser, Peter Adamík, Ana Cláudia Norte, Dávid Kováts, Zdeněk Tyller, Blandine Doligez, Ina Sabrina Tirri, Marko Mutanen, Jaime A. Ramos, Raivo Mänd, Tomáš Grim, Hein Sprong, Júlio M. Neto, Juan José Sanz, Haralambos Alivizatos, Sándor Hornok, Laure Cauchard, Savas Kazantzidis, Tapio Eeva, Frantisek Krause, Tomi Trilar, Ivan Literak, Dieter Heylen, Niels Jeroen Dingemanse, Anna Dubiec, Maria Sofia Núncio, Lucia Mentesana, Noémie S. Becker, Tibor Csörgő, Luís P. da Silva, Emilio Barba, Isabel Lopes de Carvalho, Animal Ecology (AnE), Fundação para a Ciência e a Tecnologia (Portugal), Instituto Nacional de Saúde Doutor Ricardo Jorge (Portugal), Estonian Research Council, Slovenian Research Agency, Academy of Finland, Palacky University, Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), and Zoology
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0106 biological sciences ,0301 basic medicine ,BORRELIA-BURGDORFERI ,ACARI ,medicine.disease_cause ,migration ,BURGDORFERI SENSU-LATO ,01 natural sciences ,Songbirds ,Lyme disease ,Ticks ,Acari ,Migration ,11832 Microbiology and virology ,Lyme Disease ,biology ,Plan_S-Compliant_NO ,BLACKBIRDS TURDUS-MERULA ,PREVALENCE ,Europe ,host-parasite interactions ,MIGRATORY BIRDS ,international ,1181 Ecology, evolutionary biology ,[SDE]Environmental Sciences ,Host-paraste Interations ,Host-parasite interactions ,Aves ,TRANSMISSION ,Zoology ,010603 evolutionary biology ,ticks ,Birds ,03 medical and health sciences ,Borrelia ,parasitic diseases ,Genetics ,medicine ,Animals ,Humans ,Borrelia burgdorferi ,Ecology, Evolution, Behavior and Systematics ,Lyme borreliosis ,Infecções Sistémicas e Zoonoses ,Ixodes ,Bird Diseases ,LYME-DISEASE ,IXODES-RICINUS TICKS ,Borrelia garinii ,Ecología ,biology.organism_classification ,medicine.disease ,bacterial infections and mycoses ,030104 developmental biology ,birds ,Candidatus ,WILD BIRDS ,Multilocus sequence typing ,Multilocus Sequence Typing - Abstract
Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies “Candidatus Borrelia aligera” was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts., This study received financial support from Fundação para a Ciência e a Tecnologia by the strategic program of MARE (MARE ‐ UID/MAR/04292/2013) and the fellowship to Ana Cláudia Norte (SFRH/BPD/108197/2015), and the Portuguese National Institute of Health. Raivo Mänd, Tomi Trilar, Tapio Eeva, Tomas Grim and Dieter Heylen were supported by the Estonian Research Council (research grant # IUT34‐8), the Slovenian Research Agency ‐programme “Communities, relations and communications in the ecosystems” (No. P1‐0255), the Academy of Finland (project 265859), the Internal Grant Agency of Palacky University (PrF_2014_018, PrF_2015_018, PrF_2013_018) and the Marie Sklodowska‐Curie Actions (EU‐Horizon 2020, Individual Global Fellowship, project no 799609), respectively.
- Published
- 2020
17. Uncovering dangerous cheats: how do avian hosts recognize adult brood parasites?
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Alfréd Trnka, Pavol Prokop, and Tomáš Grim
- Subjects
Medicine ,Science - Abstract
BACKGROUND: Co-evolutionary struggles between dangerous enemies (e.g., brood parasites) and their victims (hosts) lead to the emergence of sophisticated adaptations and counter-adaptations. Salient host tricks to reduce parasitism costs include, as front line defence, adult enemy discrimination. In contrast to the well studied egg stage, investigations addressing the specific cues for adult enemy recognition are rare. Previous studies have suggested barred underparts and yellow eyes may provide cues for the recognition of cuckoos Cuculus canorus by their hosts; however, no study to date has examined the role of the two cues simultaneously under a consistent experimental paradigm. METHODOLOGY/PRINCIPAL FINDINGS: We modify and extend previous work using a novel experimental approach--custom-made dummies with various combinations of hypothesized recognition cues. The salient recognition cue turned out to be the yellow eye. Barred underparts, the only trait examined previously, had a statistically significant but small effect on host aggression highlighting the importance of effect size vs. statistical significance. CONCLUSION: Relative importance of eye vs. underpart phenotypes may reflect ecological context of host-parasite interaction: yellow eyes are conspicuous from the typical direction of host arrival (from above), whereas barred underparts are poorly visible (being visually blocked by the upper part of the cuckoo's body). This visual constraint may reduce usefulness of barred underparts as a reliable recognition cue under a typical situation near host nests. We propose a novel hypothesis that recognition cues for enemy detection can vary in a context-dependent manner (e.g., depending on whether the enemy is approached from below or from above). Further we suggest a particular cue can trigger fear reactions (escape) in some hosts/populations whereas the same cue can trigger aggression (attack) in other hosts/populations depending on presence/absence of dangerous enemies that are phenotypically similar to brood parasites and costs and benefits associated with particular host responses.
- Published
- 2012
- Full Text
- View/download PDF
18. Postfledging behavior of the Common Cuckoo (Cuculus canorus) attended by the Chaffinch (Fringilla coelebs): a comprehensive approach to study the least-known stage of brood parasite–host coevolution
- Author
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Michal Kysučan, Zdeněk Tyller, and Tomáš Grim
- Subjects
0106 biological sciences ,Fringilla ,Brood parasite ,Larva ,Ecology ,biology ,Host (biology) ,05 social sciences ,Zoology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Common cuckoo ,Phoenicurus phoenicurus ,0501 psychology and cognitive sciences ,Animal Science and Zoology ,050102 behavioral science & comparative psychology ,Cuckoo ,Ecology, Evolution, Behavior and Systematics - Abstract
In contrast to the thoroughly studied incubation and nestling periods, the postfledging period of the Common Cuckoo (Cuculus canorus) remains virtually unknown. Here, we report detailed observations of a cuckoo fledgling attended by a male Chaffinch (Fringilla coelebs). Molecular data (nuclear DNA) showed the fledgling was a male belonging to the Cuculus c. canorus/C. saturatus clade while mitochondrial DNA data confirmed that it did not belong to blue egg gens that parasitizes Redstarts (Phoenicurus phoenicurus), which is the most common local host and the only regular Common Cuckoo host. During one week of observations, feeding rates did not change, body mass decreased (by 10%), and wing length increased (by 16%). Video recordings showed that the provided diet consisted mostly of larvae and that the fledgling also self-fed on lichens. A radio transmitter fitted on the fledgling revealed that daily movement distances ranged from 0 to 650 m and significantly increased with age. We suggest that fu...
- Published
- 2018
19. Consistent individual and sex-specific differences in behaviour of common cuckoo chicks: is there a potential impact on host-parasite coevolutionary dynamics?
- Author
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Tomáš Grim, Alfréd Trnka, and Peter Samaš
- Subjects
0106 biological sciences ,Brood parasite ,biology ,Aggression ,Host (biology) ,05 social sciences ,Zoology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Common cuckoo ,Behavioral Neuroscience ,medicine ,Acrocephalus ,Parasite hosting ,0501 psychology and cognitive sciences ,Animal Science and Zoology ,050102 behavioral science & comparative psychology ,medicine.symptom ,Cuckoo - Abstract
Research on brood parasitism has focused primarily on specific host anti-parasite behaviours and parasite counter-adaptations, and little is known about other aspects of their behaviours such as consistent behavioural differences between individuals. Therefore, we examined consistency in behaviour of nestlings of common cuckoos (Cuculus canorus) raised by great reed warblers (Acrocephalus arundinaceus). Cuckoo chicks showed high repeatability of both aggressive behaviour and breath rate, and both traits were strongly correlated with each other. This represents the first evidence for consistent differences in behaviour among avian brood parasites. Males were consistently more aggressive and less stressed than females. Nestlings of both sexes that hatched later in the season exhibited higher levels of aggression and lower stress responses than nestlings hatched earlier. This suggests that rearing conditions (e.g., food availability and quality) may modulate stress and aggressive phenotypes of brood parasites. We discuss potential effects of the observed patterns on host-parasite dynamics.
- Published
- 2018
20. Chick Discrimination Versus Adaptive Parasitic Egg Acceptance: The Egg Dilution Effect Hypothesis Revisited
- Author
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Tomáš Grim
- Subjects
0106 biological sciences ,Ecology ,Zoology ,Animal Science and Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,010605 ornithology ,Dilution - Published
- 2017
21. Unusual diet of brood parasitic nestlings and its fitness consequences
- Author
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Tomáš Grim, Zdeněk Tyller, and Peter Samaš
- Subjects
0106 biological sciences ,Brood parasite ,biology ,Host (biology) ,Ecology ,05 social sciences ,Zoology ,Redstart ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Brood ,Common cuckoo ,Phoenicurus phoenicurus ,Animal ecology ,0501 psychology and cognitive sciences ,Animal Science and Zoology ,050102 behavioral science & comparative psychology ,Ecology, Evolution, Behavior and Systematics - Abstract
Avian brood parasitism provides a tractable system within which to study diverse aspects of animal ecology and evolution. Yet, parasite–host research has focused on specific adaptations and counter-adaptations, such as egg rejection by hosts and egg mimicry by parasites, leaving other aspects of these relationships poorly studied, including general life history traits of hosts that did not evolve as specific antiparasite defenses. In particular, the diet and fledging parameters (age, mass, success) of parasitic nestlings are poorly known, although they are central to our understanding of host selection and the potential for coevolution in parasite–host relationships. We focused on the diet composition and fledging parameters of parasitic Common Cuckoo (Cuculus canorus) nestlings raised by their only regular cavity-nesting host, the Common Redstart (Phoenicurus phoenicurus). In addition to invertebrates, both Common Cuckoo and Common Redstart nestlings were fed fruits and lizards by some host pair...
- Published
- 2017
22. Does the house sparrowPasser domesticusrepresent a global model species for egg rejection behavior?
- Author
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Caren B. Cooper, Shane M. Baylis, Geoffrey I. N. Waterhouse, Thomas J. Manna, Mark E. Hauber, Matthew D. Shawkey, and Tomáš Grim
- Subjects
0106 biological sciences ,Brood parasite ,Facultative ,education.field_of_study ,Sparrow ,biology ,Range (biology) ,Ecology ,Population ,Parasitism ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,010605 ornithology ,Nest ,biology.animal ,Animal Science and Zoology ,education ,Passer ,Ecology, Evolution, Behavior and Systematics - Abstract
Conspecific brood parasitism (CP) is a facultative breeding tactic whereby females lay their eggs in the nests of conspecifics. In some species, potential hosts have evolved the ability to identify and reject foreign eggs from their nest. Previous studies suggest that the ubiquitous House Sparrow Passer domesticus in Spain and South Africa employs both CP and egg rejection, while a population in China does not. Given the species' invasive range expansions, the House Sparrow represents a potentially excellent global model system for parasitic egg rejection across variable ecological conditions. We examined the responses of House Sparrows to experimental parasitism at three geographically distinct locations (in Israel, North America, and New Zealand) to provide a robust test of how general the findings of the previous studies are. In all three geographic regions egg rejection rates were negligible and not statistically different from background rates of disappearance of control eggs, suggesting that the House Sparrow is not a suitable model species for egg rejection experiments on a global scale. This article is protected by copyright. All rights reserved.
- Published
- 2017
23. Growth Performance of Nestling CuckoosCuculus canorusin Cavity Nesting Hosts
- Author
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Tomáš Grim and Peter Samaš
- Subjects
0106 biological sciences ,Parus ,Brood parasite ,biology ,Ecology ,Ficedula ,Redstart ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,010605 ornithology ,Phoenicurus phoenicurus ,Nest ,Animal Science and Zoology ,Cuckoo - Abstract
Generalist brood parasites, like Common Cuckoos Cuculus canorus, target many host species. Why other sympatric hosts are not used, or actively avoided, remains one of the main gaps in our understanding of parasite-host coevolution. Cavity nesting passerines always represented a text-book example of unsuitable hosts but recent evidence casts multiple doubts on this traditional view. In general, any species can become an unsuitable host for a parasite at laying, incubation, or nestling stages with the last one being much less studied than the others. Therefore we examined Cuckoo chick performance in five cavity nesting host species, including one regular Cuckoo host — the Common Redstart Phoenicurus phoenicurus and four non-hosts: the Pied Flycatcher Ficedula hypoleuca, Spotted Flycatcher Muscicapa striata, Great Tit Parus major, and Coal Tit Periparus ater. Natural nests of non-hosts, as opposed to artificial nest boxes with small entrance holes, are often placed in cavities that show both entrance and inner cavity sizes large enough for female Cuckoos to lay and Cuckoo chicks to fledge. We did not find any evidence for chick discrimination in non-hosts, i.e., no chicks were rejected, attacked, or neglected. Cuckoo chicks grew similarly in nests of all four species of non-hosts, similarly to chicks in host Redstart nests, and generally better than in nests of the most numerous Cuckoo host, the Reed Warbler Acrocephalus scirpaceus. Although Cuckoo chick fledging mass was highly host speciesspecific (i.e., showed high statistical repeatability across various host species), we did not find any evidence for the hypothesis that host body size (mass) positively affects parasite chick growth (fledging mass or age). These findings provide impetus to further study apparently unsuitable hosts and perhaps even reconsider traditional classifications of host suitability in the context of brood parasite-host coevolution.
- Published
- 2016
24. Anti-parasitic egg rejection by great reed warblers (Acrocephalus arundinaceus) tracks differences along an eggshell color gradient
- Author
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Mikus Abolins-Abols, Mark E. Hauber, Tomáš Grim, Csaba Moskát, and Daniel Hanley
- Subjects
Brood parasite ,biology ,Host (biology) ,Zoology ,Color ,General Medicine ,Color gradient ,biology.organism_classification ,Cuculus ,Nesting Behavior ,Behavioral Neuroscience ,Egg Shell ,Nest ,embryonic structures ,Mimicry ,Acrocephalus ,Animals ,Animal Science and Zoology ,Passeriformes ,Eggshell ,Color Perception - Abstract
One of the most effective defenses against avian brood parasitism is the rejection of the foreign egg from the host’s nest. Until recently, most studies have tested whether hosts discriminate between own and foreign eggs based on their absolute differences in avian-perceivable eggshell coloration and maculation. However, recent studies suggest that hosts may instead contrast egg appearances across a directional eggshell color gradient. We assessed which discrimination rule best explained egg rejection by great reed warblers Acrocephalus arundinaceus , a frequent host to an egg-mimetic race of common cuckoos Cuculus canorus . We deployed 3D-printed model eggs varying in blue-green to brown coloration and in the presence of maculation. Using visual modeling, we calculated the absolute chromatic and achromatic just-noticeable differences (JNDs), as well as directional JNDs across a blue-green to brown egg color gradient, between host and model eggs. While most model eggs were rejected by great reed warblers, browner eggs were rejected with higher probability than more blue-green eggs, and the rejection probability did not depend on maculation. Directional egg color discrimination shown here and in a suite of recent studies on other host species may shape the cognitive decision rules that hosts use to recognize foreign eggs and affect the course of evolution in parasitic egg mimicry.
- Published
- 2019
25. Electronic supplementary material from Variation in multicomponent recognition cues alters egg rejection decisions: a test of the optimal acceptance threshold hypothesis
- Author
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Hanley, Daniel, López, Analía V., Fiorini, Vanina D., Reboreda, Juan C., Tomáš Grim, and Hauber, Mark E.
- Abstract
The optimal acceptance threshold hypothesis provides a general predictive framework for testing behavioural responses to discrimination challenges. Decision-makers should respond to a stimulus when the perceived difference between that stimulus and a comparison template surpasses an acceptance threshold. We tested how individual components of a relevant recognition cue (experimental eggs) contributed to behavioural responses of chalk-browed mockingbirds, Mimus saturninus, a frequent host of the parasitic shiny cowbird, Molothrus bonariensis. To do this, we recorded responses to eggs that varied with respect to two components: colour, ranging from bluer to browner than the hosts' own eggs, and spotting, either spotted like their own or unspotted. Although tests of this hypothesis typically assume that decisions are based on perceived colour dissimilarity between own and foreign eggs, we found that decisions were biased toward rejecting browner eggs. However, as predicted, hosts tolerated spotted eggs more than unspotted eggs, irrespective of colour. These results uncover how a single component of a multicomponent cue can shift a host’s discrimination threshold and illustrate how the optimal acceptance threshold hypothesis can be used as a framework to quantify the direction and amount of the shift (in avian perceptual units) of the response curve across relevant phenotypic ranges.This article is part of the theme issue ‘The co-evolutionary biology of brood parasitism: from mechanism to pattern’.
- Published
- 2019
- Full Text
- View/download PDF
26. Brood parasite and host eggshells undergo similar levels of decalcification during embryonic development
- Author
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Matthew D. Shawkey, Csaba Moskát, Tomáš Grim, Petr Procházka, Marcel Honza, Mark E. Hauber, and Branislav Igic
- Subjects
0106 biological sciences ,0301 basic medicine ,Brood parasite ,animal structures ,Bone decalcification ,biology ,Hatching ,Ecology ,Zoology ,Parasitism ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Common cuckoo ,03 medical and health sciences ,030104 developmental biology ,embryonic structures ,Animal Science and Zoology ,Eggshell ,Cuckoo ,Ecology, Evolution, Behavior and Systematics - Abstract
Common cuckoos Cuculus canorus are obligate brood parasites that lay their eggs in the nests of other (host) species. To increase the likelihood of successful parasitism, common cuckoos lay eggs with thicker and structurally stronger eggshells than those of their hosts and non-parasitic relatives. Although hatching from thicker eggshells requires greater effort and may impose physiological costs on cuckoo embryos during hatching, it is unclear whether cuckoo eggshells are indeed thicker at the time of hatching. This is because avian embryos decalcify the innermost eggshell layer (mammillary layer) for organ development during embryogenesis, reducing eggshell thickness and making hatching easier. Therefore, common cuckoo eggshells may undergo a greater degree of decalcification during embryonic development to facilitate hatching from an initially thicker shelled egg. We used scanning electron microscopy to test this hypothesis by comparing the thickness and degree of decalcification of eggshells collected either before incubation or after hatching. We found that cuckoo eggshells undergo similar degrees of decalcification during embryonic development as the thinner eggshells of a host that lays similarly sized eggs, the great reed warbler Acrocephalus arundinaceus. Cuckoo eggshells hence remain thicker than eggshells of this host throughout embryogenesis, supporting the predicted trade-off between the benefits of laying puncture-resistant eggs and the physiological costs associated with hatching from thick shelled eggs.
- Published
- 2016
27. Dynamic egg color mimicry
- Author
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Patricia L. R. Brennan, Tomáš Grim, Michal Šulc, Marcel Honza, Mark E. Hauber, and Daniel Hanley
- Subjects
0106 biological sciences ,0301 basic medicine ,pigments ,Zoology ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Common cuckoo ,03 medical and health sciences ,Acrocephalus ,Avian vision ,Eggshell ,Cuckoo ,Ecology, Evolution, Behavior and Systematics ,brood parasitism ,Nature and Landscape Conservation ,Original Research ,Brood parasite ,Great reed warbler ,Ecology ,biology ,biology.organism_classification ,030104 developmental biology ,coevolution ,Mimicry ,mimicry ,common cuckoo - Abstract
Evolutionary hypotheses regarding the function of eggshell phenotypes, from solar protection through mimicry, have implicitly assumed that eggshell appearance remains static throughout the laying and incubation periods. However, recent research demonstrates that egg coloration changes over relatively short, biologically relevant timescales. Here, we provide the first evidence that such changes impact brood parasite–host eggshell color mimicry during the incubation stage. First, we use long‐term data to establish how rapidly the Acrocephalus arundinaceus Linnaeus (great reed warbler) responded to natural parasitic eggs laid by the Cuculus canorus Linnaeus (common cuckoo). Most hosts rejected parasitic eggs just prior to clutch completion, but the host response period extended well into incubation (~10 days after clutch completion). Using reflectance spectrometry and visual modeling, we demonstrate that eggshell coloration in the great reed warbler and its brood parasite, the common cuckoo, changes rapidly, and the extent of eggshell color mimicry shifts dynamically over the host response period. Specifically, 4 days after being laid, the host should notice achromatic color changes to both cuckoo and warbler eggs, while chromatic color changes would be noticeable after 8 days. Furthermore, we demonstrate that the perceived match between host and cuckoo eggshell color worsened over the incubation period. These findings have important implications for parasite–host coevolution dynamics, because host egg discrimination may be aided by disparate temporal color changes in host and parasite eggs.
- Published
- 2016
28. Rearing a virulent common cuckoo is not extra costly for its only cavity-nesting host
- Author
-
Jarkko Rutila, Peter Samaš, Marcel Honza, Michal Kysučan, and Tomáš Grim
- Subjects
0106 biological sciences ,0301 basic medicine ,Brood parasite ,General Immunology and Microbiology ,Host (biology) ,Virulence ,Zoology ,General Medicine ,Biology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Common cuckoo ,03 medical and health sciences ,030104 developmental biology ,Behaviour ,General Agricultural and Biological Sciences ,Paternal care ,General Environmental Science - Abstract
Virulent brood parasites refrain from arduous parental care, often kill host progeny and inflict rearing costs upon their hosts. Quantifying the magnitude of such costs across the whole period of care (from incubation through to parasite fledgling independence) is essential for understanding the selection pressures on hosts to evolve antiparasitic defences. Despite the central importance of such costs for our understanding of coevolutionary dynamics, they have not yet been comprehensively quantified in any host of any avian brood parasite. We quantified parasite-rearing costs in common redstarts Phoenicurus phoenicurus raising either parasitic common cuckoo Cuculus canorus or their own chicks throughout the complete breeding cycle, and used multiple cost parameters for each breeding stage: incubation, brooding and feeding effort; length of parental/host care; parent/host body condition; and heterophil/lymphocyte ratio (stress-level indicator). Contrary to traditional assumptions, rearing the parasite per se was not associated with overall higher physiological or physical costs to hosts above the natural levels imposed by efforts to rear their own progeny. The low parasite-rearing costs imposed on hosts may, in part, explain the low levels of known host counter-defences in this unusually frequently parasitized cuckoo host.
- Published
- 2018
29. Probing the Limits of Egg Recognition Using Egg Rejection Experiments Along Phenotypic Gradients
- Author
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Analía V. López, Daniel Hanley, Miri Dainson, Peter Samaš, Mark E. Hauber, Tomáš Grim, and Lindsay Canniff
- Subjects
Color vision ,General Chemical Engineering ,Zoology ,Parasitism ,Common method ,Biology ,General Biochemistry, Genetics and Molecular Biology ,Nesting Behavior ,Birds ,03 medical and health sciences ,0302 clinical medicine ,Nest ,Animals ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Ovum ,Brood parasite ,General Immunology and Microbiology ,Host (biology) ,General Neuroscience ,05 social sciences ,This Month in JoVE ,Biological evolution ,Biological Evolution ,embryonic structures ,Standard protocol ,Female ,030217 neurology & neurosurgery - Abstract
Brood parasites lay their eggs in other females' nests, leaving the host parents to hatch and rear their young. Studying how brood parasites manipulate hosts into raising their young and how hosts detect parasitism provide important insights in the field of coevolutionary biology. Brood parasites, such as cuckoos and cowbirds, gain an evolutionary advantage because they do not have to pay the costs of rearing their own young. However, these costs select for host defenses against all developmental stages of parasites, including eggs, their young, and adults. Egg rejection experiments are the most common method used to study host defenses. During these experiments, a researcher places an experimental egg in a host nest and monitors how hosts respond. Color is often manipulated, and the expectation is that the likelihood of egg discrimination and the degree of dissimilarity between the host and experimental egg are positively related. This paper serves as a guide for conducting egg rejection experiments from describing methods for creating consistent egg colors to analyzing the findings of such experiments. Special attention is given to a new method involving uniquely colored eggs along color gradients that has the potential to explore color biases in host recognition. Without standardization, it is not possible to compare findings between studies in a meaningful way; a standard protocol within this field will allow for increasingly accurate and comparable results for further experiments.
- Published
- 2018
30. Stability of a behavioural syndrome vs. plasticity in individual behaviours over the breeding cycle: Ultimate and proximate explanations
- Author
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Alfréd Trnka, Peter Samaš, and Tomáš Grim
- Subjects
0106 biological sciences ,media_common.quotation_subject ,Context (language use) ,Plasticity ,010603 evolutionary biology ,01 natural sciences ,Developmental psychology ,Nesting Behavior ,Songbirds ,Behavioral Neuroscience ,Nest ,Acrocephalus ,medicine ,Personality ,Animals ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,media_common ,Phenotypic plasticity ,Great reed warbler ,biology ,Behavior, Animal ,Aggression ,Reproduction ,05 social sciences ,General Medicine ,biology.organism_classification ,Phenotype ,Animal Science and Zoology ,Female ,medicine.symptom - Abstract
Animals often show correlated suites of consistent behavioural traits, i.e., personality or behavioural syndromes. Does this conflict with potential phenotypic plasticity which should be adaptive for animals facing various contexts and situations? This fundamental question has been tested predominantly in studies which were done in non-breeding contexts and under laboratory conditions. Therefore, in the present study we examined the temporal stability of behavioural correlations in a breeding context and under natural conditions. We found that in the great reed warbler (Acrocephalus arundinaceus) females, the intensity of their nest defence formed a behavioural syndrome with two other traits: their aggression during handling (self-defence) and stress responses during handling (breath rate). This syndrome was stable across the nesting cycle: each of the three behavioural traits was highly statistically repeatable between egg and nestling stages and the traits were strongly correlated with each other during both the egg stage and the nestling stage. Despite this consistency (i.e., rank order between stages) the individual behaviours changed their absolute values significantly during the same period. This shows that stable behavioural syndromes might be based on behaviours that are themselves unstable. Thus, syndromes do not inevitably constrain phenotypic plasticity. We suggest that the observed behavioural syndrome is the product of interactions between behavioural and life history trade-offs and that crucial proximate mechanisms for the plasticity and correlations between individual behaviours are hormonally-regulated.
- Published
- 2018
31. Statistical details and clutch size distributions from Rearing a virulent common cuckoo is not extra costly for its only cavity-nesting host
- Author
-
Samaš, Peter, Rutila, Jarkko, Honza, Marcel, Kysučan, Michal, and Tomáš Grim
- Abstract
Virulent brood parasites refrain from arduous parental care, often kill host progeny and inflict rearing costs upon their hosts. Quantifying the magnitude of such costs across the whole period of care (from incubation through to parasite fledgling independence) is essential for understanding the selection pressures on hosts to evolve antiparasitic defences. Despite the central importance of such costs for our understanding of coevolutionary dynamics, they have not yet been comprehensively quantified in any host of any avian brood parasite. We quantified parasite-rearing costs in common redstarts Phoenicurus phoenicurus raising either parasitic common cuckoo Cuculus canorus or their own chicks throughout the complete breeding cycle and used multiple cost parameters for each breeding stage: incubation, brooding and feeding effort; length of parental/host care; parent/host body condition and the heterophil/lymphocyte ratio (stress-level indicator). Surprisingly and contrary to traditional assumptions, rearing the parasite per se was not associated with overall higher physiological or physical costs to hosts above the natural levels imposed by efforts to rear their own progeny. The low parasite-rearing costs imposed on hosts may, in part, explain the low levels of known host counter-defences in this unusually frequently parasitized cuckoo host.
- Published
- 2018
- Full Text
- View/download PDF
32. A comparison of egg yolk lipid constituents between parasitic Common Cuckoos and their hosts
- Author
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Erica Zarate, Matthew D. Shawkey, Jarkko Rutila, Branislav Igic, Tomáš Grim, Mark E. Hauber, Csaba Moskát, Phillip Cassey, and Mary A. Sewell
- Subjects
Brood parasite ,food.ingredient ,biology ,Reproductive success ,Host (biology) ,Ecology ,media_common.quotation_subject ,Zoology ,biology.organism_classification ,Cuculus ,Competition (biology) ,food ,Yolk ,embryonic structures ,Acrocephalus ,Animal Science and Zoology ,Cuckoo ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
Common Cuckoos (Cuculus canorus) are obligate brood parasites that lay their eggs in nests of other species and use these hosts to raise their parasitic offspring. Two key adaptations that increase their reproductive success are (1) the capacity for cuckoos to lay large numbers of eggs and thereby parasitize many nests per year, and (2) the ability of cuckoo eggs to hatch before those of hosts, enabling cuckoo nestlings to evict host eggs and eliminate competition for food. Producing more eggs is generally associated with reduced investment of nutrients and energy reserves per egg, which in turn is associated with shorter incubation periods both within and between species. We hypothesized that Common Cuckoos deposit reduced energy reserves into their eggs than do their hosts to facilitate both (1) and (2). To test these hypotheses, we compared the concentration of yolk lipids (per wet yolk mass) between eggs of 3 cuckoo gentes and their respective host species: Great Reed Warblers (Acrocephalus a...
- Published
- 2015
33. Predicting the responses of native birds to transoceanic invasions by avian brood parasites
- Author
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Vladimir Dinets, Tomáš Grim, Mark E. Hauber, Rebecca Croston, and Peter Samaš
- Subjects
0106 biological sciences ,Brood parasite ,Cowbird ,biology ,Ecology ,05 social sciences ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cuculus ,Common cuckoo ,Phoenicurus phoenicurus ,13. Climate action ,Sympatric speciation ,Seasonal breeder ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Cuckoo ,Ecology, Evolution, Behavior and Systematics - Abstract
Three species of brood parasites are increasingly being recorded as transoceanic vagrants in the Northern Hemisphere, including two Cuculus cuckoos from Asia to North America and a Molothrus cowbird from North America to Eurasia. Vagrancy patterns suggest that their establishment on new continents is feasible, possibly as a consequence of recent range increases in response to a warming climate. The impacts of invasive brood parasites are predicted to differ between continents because many host species of cowbirds in North America lack egg rejection defenses against native and presumably also against invasive parasites, whereas many hosts of Eurasian cuckoos frequently reject non-mimetic, and even some mimetic, parasitic eggs from their nests. During the 2014 breeding season, we tested the responses of native egg-rejecter songbirds to model eggs matching in size and color the eggs of two potentially invasive brood parasites. American Robins (Turdus migratorius) are among the few rejecters of the eggs of Brown-headed Cowbirds (M. ater), sympatric brood parasites. In our experiments, robins rejected one type of model eggs of a Common Cuckoo (C. canorus) host-race, but accepted model eggs of a second cuckoo host-race as well as robin-mimetic control eggs. Common Redstarts (Phoenicurus phoenicurus), frequent hosts of Common Cuckoos in Eurasia, rejected ∼50% of model Brown-headed Cowbird eggs and accepted most redstart-mimetic control eggs. Our results suggest that even though some hosts have evolved egg-rejection defenses against native brood parasites, the invasion of brood parasites into new continents may negatively impact both naive accepter and coevolved rejecter songbirds in the Northern Hemisphere.
- Published
- 2015
34. The cuticle modulates ultraviolet reflectance of avian eggshells
- Author
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Branislav Igic, Matthew D. Shawkey, Geoffrey I. N. Waterhouse, Tomáš Grim, Daniel Hanley, Mark E. Hauber, Daphne Fecheyr-Lippens, Liliana D'Alba, Aida Verdes, and Mandë Holford
- Subjects
Cuticle ,QH301-705.5 ,Science ,Light modulation ,Biology ,medicine.disease_cause ,General Biochemistry, Genetics and Molecular Biology ,Pigment ,chemistry.chemical_compound ,Botany ,medicine ,Biomimicry ,Eggshell ,Biology (General) ,Cuticle (hair) ,Chemical dissolution ,Biliverdin ,Avian eggshells ,Reflectivity ,chemistry ,visual_art ,visual_art.visual_art_medium ,Biophysics ,General Agricultural and Biological Sciences ,Ultraviolet ,Structural coloration ,Ultraviolet reflectance ,Research Article - Abstract
Avian eggshells are variedly coloured, yet only two pigments, biliverdin and protoporphyrin IX, are known to contribute to the dramatic diversity of their colours. By contrast, the contributions of structural or other chemical components of the eggshell are poorly understood. For example, unpigmented eggshells, which appear white to the human eye, vary in their ultraviolet (UV) reflectance, which may be detectable by birds. We investigated the proximate mechanisms for the variation in UV-reflectance of unpigmented bird eggshells using spectrophotometry, electron microscopy, chemical analyses, and experimental manipulations. We specifically tested how UV-reflectance is affected by the eggshell cuticle, the outermost layer of most avian eggshells. The chemical dissolution of the outer eggshell layers, including the cuticle, increased UV-reflectance for only eggshells that contained a cuticle. Our findings demonstrate that the outer eggshell layers, including the cuticle, absorb UV-light, probably because they contain higher levels of organic components and other chemicals, such as calcium phosphates, compared to the predominantly calcite-based eggshell matrix. These data highlight the need to examine factors other than the known pigments in studies of avian eggshell colour.
- Published
- 2015
35. Interactive effects of fearfulness and geographical location on bird population trends
- Author
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Jukka Jokimäki, Einar Flensted-Jensen, Gábor Markó, José Javier Cuervo, Anders Pape Møller, Mario Díaz, Tomáš Grim, Juan Diego Ibáñez-Álamo, and Piotr Tryjanowski
- Subjects
education.field_of_study ,Latitude ,Ecology ,Flight initiation distance ,Population ,Biology ,Marginality of distribution ,Breeding birds ,Thematic map ,Interactive effects ,Regional development ,Longitude ,Animal Science and Zoology ,education ,Location ,Cartography ,Ecology, Evolution, Behavior and Systematics - Abstract
Animal populations are currently under pressure from multiple factors that include human land use and climate change. They may compensate for such effects by reducing, either by habituation or by natural selection, the distance at which they flee from humans (i.e., flight initiation distance), and this adaptation may improve their population trends. We analyzed population trends of common breeding birds in relation to flight initiation distance and geographical location (latitude, longitude, and marginality of the breeding distribution) across European countries from Finland in the north to Spain in the south while also considering other potential predictors of trends like farmland habitat, migration, body size, and brain size. We found evidence of farmland, migratory, and smaller-sized species showing stronger population declines. In contrast, there was no significant effect of relative brain size on population trends. We did not find evidence for main effects of flight initiation distance and geographical location on trends after accounting for confounding and interactive effects; instead, flight initiation distance and location interacted to generate complex spatial patterns of population trends. Trends were more positive for fearful populations northward, westward, and (marginally) toward the center of distribution areas and more negative for fearless populations toward the south, east, and the margins of distribution ranges. These findings suggest that it is important to consider differences in population trends among countries, but also interaction effects among factors, because such interactions can enhance or compensate for negative effects of other factors on population trends., J.J.C. was supported by the Spanish National Research Council (EST001196)., This article is a contribution by M.D. to the project RiskDisp (CGL2009-08430) and to the thematic networks GlobiMed (www.globimed.net) and REMEDINAL III. JJ received support from the EU Regional Development Fund via the Project “Rovaniemen kaupunkilintuatlas (A31026).
- Published
- 2015
36. Effects of urbanization on bird phenology
- Author
-
Raivo Maend, Jukka Jokimäki, Juan Diego Ibáñez-Álamo, Mario Díaz, Alena Dvorska, Paweł Szymański, Piotr Tryjanowski, Tomáš Grim, Einar Flensted-Jensens, Gábor Markó, Anders Pape Møller, and Piersma group
- Subjects
Atmospheric Science ,CITY ,Growing season ,FLIGHT INITIATION DISTANCE ,Population density ,COLONIZATION ,Common species ,Urbanization ,Seasonal breeder ,Environmental Chemistry ,General Environmental Science ,PREDATION ,Phenology ,Ecology ,EUROPEAN BLACKBIRDS ,BLACKBIRDS TURDUS-MERULA ,BREEDING SEASONS ,REPRODUCTION ,Geography ,Habitat ,DOMESTICATION ,Rural area ,Singing periods ,ENVIRONMENTS - Abstract
Urban habitats differ from adjacent natural habitats in terms of disturbance regimes, light, temperature, rainfall, habitat distribution and resource abundance. Meteorological differences advance and prolong the growing season in urban habitats compared to nearby rural areas. In turn, urban bird populations may potentially start singing earlier, and reproduce earlier and more frequently than rural populations. However, this prediction has previously only been tested with data from single species using single spatial replicates from rural and urban sites. Here we provide the first general (paired urban and rural populations of 54 bird species) and large-scale (a 3800 km long latitudinal gradient across Europe) empirical evidence for longer and earlier singing periods in urban compared to rural habitats. Effects of urbanization on start and duration of the singing period (as a proxy for the breeding season) were positively related to size of cities and ecological characteristics of species. Bird species that have been urbanized for a long time started to sing earlier and had a more extended singing period in urban compared to rural habitats. We also found that the singing period started later and was shorter at higher latitudes. Geographical variation in phenology was related to temperature and rainfall, although differences between urban and rural habitats were not. Differences in duration of singing periods between paired urban and rural sites were as large as latitudinal differences between southern and northern Europe (5, 6 and 28 d for 3 common species, as compared to a mean latitudinal variation of 17.1 d). This suggests local adjustment to urban environments, either due to evolution or to plasticity of phenological behaviour.
- Published
- 2015
37. Rural-Urban Differences in Escape Behavior of European Birds across a Latitudinal Gradient
- Author
-
Kunter Tätte, Jukka Jokimäki, Mario Díaz, Piotr Tryjanowski, Juan Diego Ibáñez-Álamo, Tomáš Grim, Diogo S. M. Samia, Daniel T. Blumstein, Gábor Markó, Anders Pape Møller, and Tieleman lab
- Subjects
0106 biological sciences ,0301 basic medicine ,LIFE-HISTORY ,Buffer distance ,Flight initiation distance ,lcsh:Evolution ,Ecology and Evolution ,Wildlife ,pre-detection distance ,NEST PREDATION ,Escape response ,urbanization ,FEAR ,010603 evolutionary biology ,01 natural sciences ,Phi index ,Predation ,Latitude ,03 medical and health sciences ,alert distance ,lcsh:QH540-549.5 ,Urbanization ,lcsh:QH359-425 ,antipredator behavior ,phi index ,buffer distance ,DISTURBANCE ,Ecology, Evolution, Behavior and Systematics ,Rural-urban difference ,CONSEQUENCES ,Ecology ,HYPOTHESIS ,Flight initiation ,rural-urban difference ,Pre-detection distance ,Antipreator behavior ,030104 developmental biology ,Geography ,SIZE ,Disturbance (ecology) ,flight initiation distance ,FLIGHT-INITIATION DISTANCE ,Alert-distance ,lcsh:Ecology ,Risk assessment ,INDIVIDUAL CONSISTENCY - Abstract
Behavioral adjustment is a key factor that facilitates species’ coexistence with humans in a rapidly urbanizing world. Because urban animals often experience reduced predation risk compared to their rural counterparts, and because escape behavior is energetically costly, we expect that urban environments will select for increased tolerance to humans. Many studies have supported this expectation by demonstrating that urban birds have reduced flight initiation distance (FID = predator-prey distance when escape by the prey begins) than rural birds. Here, we advanced this approach and, for the first time, assessed how 32 species of birds, found in 92 paired urban-rural populations, along a 3,900 km latitudinal gradient across Europe, changed their predation risk assessment and escape strategy as a function of living in urban areas. We found that urban birds took longer than rural birds to be alerted to human approaches, and urban birds tolerated closer human approach than rural birds. While both rural and urban populations took longer to become aware of an approaching human as latitude increased, this behavioral change with latitude is more intense in urban birds (for a given unit of latitude, urban birds increased their pre-detection distance more than rural birds). We also found that as mean alert distance was shorter, urban birds escaped more quickly from approaching humans, but there was no such a relationship in rural populations. Although, both rural and urban populations tended to escape more quickly as latitude increased, urban birds delayed their escape more at low latitudes when compared with rural birds. These results suggest that urban birds in Europe live under lower predation risk than their rural counterparts. Furthermore, the patterns found in our study indicate that birds prioritize the reduction of on-going monitoring costs when predation risk is low. We conclude that splitting escape variables into constituent components may provide additional and complementary information on the underlying causes of escape. This new approach is essential for understanding, predicting, and managing wildlife in a rapidly urbanizing world.
- Published
- 2017
38. Does contrast between eggshell ground and spot coloration affect egg rejection?
- Author
-
Mark E. Hauber, Tomáš Grim, Analía V. López, Miri Dainson, and Daniel Hanley
- Subjects
0106 biological sciences ,Brood parasite ,Cowbird ,genetic structures ,Spots ,biology ,Obligate ,Ecology ,Host (biology) ,05 social sciences ,General Medicine ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Brood ,Nesting Behavior ,Songbirds ,Egg Shell ,Nest ,Animals ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Eggshell ,Ecology, Evolution, Behavior and Systematics ,Ovum - Abstract
Obligate avian brood parasitic species impose the costs of incubating foreign eggs and raising young upon their unrelated hosts. The most common host defence is the rejection of parasitic eggs from the nest. Both egg colours and spot patterns influence egg rejection decisions in many host species, yet no studies have explicitly examined the role of variation in spot coloration. We studied the American robin Turdus migratorius, a blue-green unspotted egg-laying host of the brown-headed cowbird Molothrus ater, a brood parasite that lays non-mimetic spotted eggs. We examined host responses to model eggs with variable spot coloration against a constant robin-mimetic ground colour to identify patterns of rejection associated with perceived contrast between spot and ground colours. By using avian visual modelling, we found that robins were more likely to reject eggs whose spots had greater chromatic (hue) but not achromatic (brightness) contrast. Therefore, egg rejection decision rules in the American robin may depend on the colour contrast between parasite eggshell spot and host ground coloration. Our study also suggests that egg recognition in relation to spot coloration, like ground colour recognition, is tuned to the natural variation of avian eggshell spot colours but not to unnatural spot colours.
- Published
- 2017
39. Host Defences Against Brood Parasite Nestlings: Theoretical Expectations and Empirical Evidence
- Author
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Tomáš Grim
- Subjects
0106 biological sciences ,Brood parasite ,animal structures ,Host (biology) ,05 social sciences ,Parasitism ,Zoology ,Biology ,010603 evolutionary biology ,01 natural sciences ,Life history theory ,embryonic structures ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Empirical evidence ,Coevolution - Abstract
In the past, chick discrimination was assumed to be non-existent without virtually any research invested to check the reality. Models of brood parasitism considered the benefits of chick rejection small and costs too high; consequently, the nestling stage was long ignored in studies of host–parasite coevolution. Remarkably, the majority of recent studies that addressed parasite chick biology did find evidence for host behaviours that alleviate the costs of parasitism during nestling stage. Most of the hosts that (apparently) discriminate against parasite chicks are acceptors of natural parasite eggs; this pattern is in line with the rarer enemy model. The main impetus for future work is therefore not naively assuming but empirically checking the (non)-existence of chick discrimination to show how common is chick discrimination in reality. This will allow to elucidate mechanisms of chick discrimination, both those that specifically evolved as a response to past parasitism pressure and those stemming from non-specific general host life history traits, and factors that facilitate or constrain their evolution.
- Published
- 2017
40. Cuckoo–Host Coevolutionary Interactions Across All Breeding Stages: Unusual Ecological Setting of a Cavity-Nesting Host
- Author
-
Jarkko Rutila and Tomáš Grim
- Subjects
0106 biological sciences ,0301 basic medicine ,Brood parasite ,biology ,Ecology ,Parasitism ,Redstart ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Brood ,Common cuckoo ,03 medical and health sciences ,030104 developmental biology ,Nest ,Cuckoo ,Coevolution - Abstract
The great majority of brood parasitism studies focused on a single ontogenetic stage, typically egg stage, and on open-nesting hosts, especially those of the common cuckoo. Using extensive data from the cuckoo’s only known regular cavity-nesting host, the common redstart, we highlight the importance of a comprehensive approach when all ontogenetic stages are studied. In contrast to open-nesting hosts, only minority of the cuckoo eggs are a threat to redstart hosts: most are laid outside the host nest cup and perish. Contrary to previous claims, we found that the impact of parasitism per host nest was virtually the same between this only regular cuckoo cavity-nesting host and a typical open-nesting host (the reed warbler): in both species, fitness of an average non-parasitized host nest was by an order of magnitude higher than fitness of an average parasitized host nest. This was partly because of uniquely low eviction success of cuckoo chicks and resulting cohabitation of parasite and host progeny in mixed broods. Data from post-fledging period, which remains the least known stage of parasite–host coevolution in any study system globally, were crucial because they showed that data from nestling period greatly overestimated cuckoo fitness. We suggest that metareplication of these approaches (i.e. integrative study of laying, incubation, nestling, fledgling and migration stages) across various parasite–host systems is the most important task for future coevolutionary studies in the context of brood parasite–host coevolution.
- Published
- 2017
41. Electronic supplementary material from Egg discrimination along a gradient of natural variation in eggshell coloration
- Author
-
Hanley, Daniel, Tomáš Grim, Igic, Branislav, Samaš, Peter, López, Analía V., Shawkey, Matthew D., and Hauber, Mark E.
- Abstract
Extended Materials and Methods
- Published
- 2017
- Full Text
- View/download PDF
42. Egg discrimination along a gradient of natural variation in eggshell coloration
- Author
-
Branislav Igic, Mark E. Hauber, Matthew D. Shawkey, Peter Samaš, Analía V. López, Tomáš Grim, and Daniel Hanley
- Subjects
0106 biological sciences ,OIL DROPLETS ,Total degree ,genetic structures ,SAYORNIS-PHOEBE ,01 natural sciences ,Nesting Behavior ,Egg Shell ,Colour perception ,Contrast (vision) ,CATEGORICAL PERCEPTION ,Eggshell ,Natural gradient ,brood parasitism ,General Environmental Science ,media_common ,Categorical perception ,Ecology ,05 social sciences ,General Medicine ,REJECTION ,embryonic structures ,recognition ,General Agricultural and Biological Sciences ,Research Article ,media_common.quotation_subject ,egg discrimination ,Color ,Zoology ,colour perception ,Biology ,Natural variation ,010603 evolutionary biology ,General Biochemistry, Genetics and Molecular Biology ,decision making ,Birds ,MOLOTHRUS-ATER ,Animals ,0501 psychology and cognitive sciences ,050102 behavioral science & comparative psychology ,Ovum ,Brood parasite ,General Immunology and Microbiology ,Biology and Life Sciences ,decision-making ,EVOLUTION ,CUCULUS-CANORUS ,CUCKOO-HOST COEVOLUTION ,Physics and Astronomy ,AVIAN BROOD PARASITES ,egg ,RESPONSES ,discrimination - Abstract
Accurate recognition of salient cues is critical for adaptive responses, but the underlying sensory and cognitive processes are often poorly understood. For example, hosts of avian brood parasites have long been assumed to reject foreign eggs from their nests based on the total degree of dissimilarity in colour to their own eggs, regardless of the foreign eggs' colours. We tested hosts' responses to gradients of natural (blue-green to brown) and artificial (green to purple) egg colours, and demonstrate that hosts base rejection decisions on both the direction and degree of colour dissimilarity along the natural, but not artificial, gradient of egg colours. Hosts rejected brown eggs and accepted blue-green eggs along the natural egg colour gradient, irrespective of the total perceived dissimilarity from their own egg's colour. By contrast, their responses did not vary along the artificial colour gradient. Our results demonstrate that egg recognition is specifically tuned to the natural gradient of avian eggshell colour and suggest a novel decision rule. These results highlight the importance of considering sensory reception and decision rules when studying perception, and illustrate that our understanding of recognition processes benefits from examining natural variation in phenotypes.
- Published
- 2017
43. Who moved my eggs? An experimental test of the egg arrangement hypothesis for the rejection of brood parasitic eggs
- Author
-
Peter Samaš, Tomáš Grim, Mark E. Hauber, and Daniel Hanley
- Subjects
Reproductive strategy ,Zoology ,Parasitism ,Experimental and Cognitive Psychology ,Biology ,Host-Parasite Interactions ,Nesting Behavior ,Incubation period ,Songbirds ,Image processing ,Animals ,Ecology, Evolution, Behavior and Systematics ,Ovum ,Brood parasite ,Original Paper ,Ecology ,Host (biology) ,European blackbird ,Brood ,Egg arrangement ,Recognition ,Brood parasitism ,embryonic structures ,Female ,Blackbird ,Paternal care - Abstract
Avian brood parasitism is an exceptional reproductive strategy whereby parasites reduce their own costs associated with parental care and impose them on the host parents. Consequently, host species have evolved multiple defensive mechanisms to combat parasitism. The vast majority of research attention to date has examined host defenses to recognize and reject parasitic eggs. The recently proposed “egg arrangement hypothesis” suggests that hosts may not focus solely on individual eggs’ features, but instead the overall arrangement of the clutch may also provide a cue that parasitism has occurred. Correlative data revealed that host females maintaining a consistent egg arrangement across the incubation period were more likely to reject foreign egg models than females that did not keep a consistent egg arrangement. Here, we provide the first experimental test of this hypothesis in the European blackbird (Turdus merula). We experimentally parasitized nests such that the egg arrangement was either disrupted or not disrupted. We found no evidence that altered egg arrangement was used as a cue for egg rejection by host females. Therefore, we suggest that females that keep consistent egg arrangement are more likely to eject foreign eggs for other correlated reasons. Thus, egg arrangement does not serve as an independent cue to trigger egg rejection responses to parasitism in this host species. Electronic supplementary material The online version of this article (doi:10.1007/s10071-014-0800-x) contains supplementary material, which is available to authorized users.
- Published
- 2014
44. Testing for correlations between behaviours in a cuckoo host: why do host defences not covary?
- Author
-
Tomáš Grim and Alfréd Trnka
- Subjects
Brood parasite ,biology ,Ecology ,Aggression ,Host (biology) ,Zoology ,Context (language use) ,biology.organism_classification ,Cuculus ,Nest ,Acrocephalus ,medicine ,Animal Science and Zoology ,medicine.symptom ,Cuckoo ,Ecology, Evolution, Behavior and Systematics - Abstract
Fitness costs associated with brood parasitism have led host species to evolve several lines of defence. The first two lines of defence, aggression against adult parasites and egg rejection, are present at varying levels in almost all hosts. However, it remains unclear how these two fundamental defences covary at host individual level, with previous studies suggesting both positive and negative correlations. A theoretically critical yet empirically untested scenario is that variation in host antiparasite behaviour may relate to individual variation in host behavioural types or personalities. Here we examined whether host aggression against adult brood parasites and egg rejection behaviour were correlated with host behaviours displayed outside the context of brood parasitism. We selected the great reed warbler, Acrocephalus arundinaceus, a favourite cuckoo, Cuculus canorus, host as a suitable model. Only females reject foreign eggs and show high individual repeatability of both aggression towards cuckoos and nest guarding. We found that female behaviours in different situations (nest guarding, nest defence, handling in the net) were strongly correlated with each other. This is the first empirical evidence on correlation between individually consistent antiparasite adaptation (female nest defence) and behaviours that are not directly related to brood parasitism. In contrast, egg rejection/acceptance responses and latency to these responses did not correlate with any of the female defence/guarding behaviours and behaviour during handling. Proximately, this may be because nest defence and egg recognition represent cognitively and behaviourally completely different tasks. These patterns were not affected by female mating status in this polygynous cuckoo host. We hypothesize that differences in host behavioural types, rather than host egg discrimination ability, may predict host nest defence behaviour against adult brood parasites in general.
- Published
- 2014
45. Dynamic risk assessment: does a nearby breeding nest predator affect nest defence of its potential victim?
- Author
-
Alfréd Trnka and Tomáš Grim
- Subjects
Ixobrychus minutus ,Great reed warbler ,Nest ,Animal ecology ,Ecology ,Acrocephalus ,Animal Science and Zoology ,Biology ,biology.organism_classification ,Nest box ,Ecology, Evolution, Behavior and Systematics ,Streptopelia turtur ,Predation - Abstract
There is growing evidence that birds are able to discriminate different types of nest intruders and adjust their nest defence behaviour according to intruder dangerousness and distance from the nest (the dynamic risk assessment hypothesis). Here, we tested whether birds’ decisions about nest defence may additionally be affected by an increasing familiarity with a particular nest predator. We tested nest defence responses of great reed warblers Acrocephalus arundinaceus to a nest predator, the little bittern Ixobrychus minutus. Great reed warbler nests located close (≤7 m) to synchronously breeding little bitterns were “neighbour”, other nests were “solitary”. Great reed warbler specific aggression towards a little bittern dummy was much lower (~5-times) at neighbour than solitary nests. In contrast, generalised responses to a control innocuous intruder (the turtle dove, Streptopelia turtur) were statistically identical at neighbour and solitary nests. These patterns are in line with dynamic risk assessment hypothesis. We hypothesise that decreased great reed warbler aggression at neighbour nests also represents a specific behavioural adaptation to nesting in association with the little bittern. Little bitterns breeding closer to great reed warblers showed decreased risks of failure due to predation. However, further research is needed to experimentally test the causal links behind these patterns.
- Published
- 2014
46. The repeatability of avian egg ejection behaviors across different temporal scales, breeding stages, female ages and experiences
- Author
-
Peter Samaš, Tomáš Grim, and Mark E. Hauber
- Subjects
education.field_of_study ,animal structures ,Ecology ,Population ,Parasitism ,Repeatability ,Biology ,Behavioral traits ,Animal science ,Animal ecology ,Seasonal breeder ,Animal Science and Zoology ,education ,Animal species ,Ecology, Evolution, Behavior and Systematics - Abstract
An evolutionarily fundamental, yet rarely examined, aspect of host–parasite arms races is the repeatability of individual host responses to parasitism. We examined the repeatability of egg ejection, and the latency to eject, across a time-scale of days (within one breeding attempt), weeks and months (between breeding attempts within one breeding season), and years (across different breeding seasons). The ejection of non-mimetic model eggs by European blackbirds, Turdus merula, showed overall high repeatability (r ~ 0.70) and, similar to empirical patterns on most other behavioral traits already studied, showed decreasing repeatability with time. In contrast, latency to ejection showed negligible repeatability overall (r ~0.20) and did not change with time. Ejection rates, latencies to ejection and the repeatability of egg ejection did not differ between young and old females. Previous experience with experimentation (number of model eggs the female received before the focal trial) marginally non-significantly covaried with egg ejection (positively) and with latency to egg ejection (negatively). Repeatability estimates for both egg ejection and latency to egg ejection at the within one breeding attempt time-scale did not statistically differ from those reported in a previous study of a different blackbird population (introduced population in New Zealand). To our knowledge, this is the first comparison of behavioral repeatability between a native vs. introduced population of any animal species.
- Published
- 2014
47. Nesting behaviour influences species-specific gas exchange across avian eggshells
- Author
-
Gavin H. Thomas, Steven J. Portugal, Mark E. Hauber, Phillip Cassey, Golo Maurer, and Tomáš Grim
- Subjects
Arboreal locomotion ,Physiology ,Microclimate ,Aquatic Science ,Biology ,Permeability ,Nesting Behavior ,Birds ,Egg Shell ,Nest ,Species Specificity ,Museum specimens ,Animals ,Eggshell ,Nest environment ,Life history ,Molecular Biology ,Incubation ,Ecology, Evolution, Behavior and Systematics ,Research Articles ,Phylogeny ,Avian eggshells ,Ecology ,Hatching ,Plumage ,Insect Science ,Animal Science and Zoology ,Desiccation - Abstract
Carefully controlled gas exchange across the eggshell is essential for the development of the avian embryo. Water vapour conductance (G(H2O)) across the shell, typically measured as mass loss during incubation, has been demonstrated to optimally ensure the healthy development of the embryo while avoiding desiccation. Accordingly, eggs exposed to sub-optimal gas exchange have reduced hatching success. We tested the association between eggshell G(H2O) and putative life-history correlates of adult birds, ecological nest parameters and physical characteristics of the egg itself to investigate how variation in G(H2O) has evolved to maintain optimal water loss across a diverse set of nest environments. We measured gas exchange through eggshell fragments in 151 British breeding bird species and fitted phylogenetically controlled, general linear models to test the relationship between G(H2O) and potential predictor parameters of each species. Of our 17 life-history traits, only two were retained in the final model: wet-incubating parent and nest type. Eggs of species where the parent habitually returned to the nest with wet plumage had significantly higher G(H2O) than those of parents that returned to the nest with dry plumage. Eggs of species nesting in ground burrows, cliffs and arboreal cups had significantly higher G(H2O) than those of species nesting on the ground in open nests or cups, in tree cavities and in shallow arboreal nests. Phylogenetic signal (measured as Pagel's λ) was intermediate in magnitude, suggesting that differences observed in the G(H2O) are dependent upon a combination of shared ancestry and species-specific life history and ecological traits. Although these data are correlational by nature, they are consistent with the hypothesis that parents constrained to return to the nest with wet plumage will increase the humidity of the nest environment, and the eggs of these species have evolved a higher G(H2O) to overcome this constraint and still achieve optimal water loss during incubation. We also suggest that eggs laid in cup nests and burrows may require a higher G(H2O) to overcome the increased humidity as a result from the confined nest microclimate lacking air movements through the nest. Taken together, these comparative data imply that species-specific levels of gas exchange across avian eggshells are variable and evolve in response to ecological and physical variation resulting from parental and nesting behaviours.
- Published
- 2014
48. Multiple costs are relevant for evolution of host anti-parasite defences. Reply to Yang C et al . (2018)
- Author
-
Tomáš Grim, Marcel Honza, Michal Kysučan, and Peter Samaš
- Subjects
General Immunology and Microbiology ,Evolutionary biology ,Host (biology) ,Parasite hosting ,General Medicine ,Biology ,General Agricultural and Biological Sciences ,General Biochemistry, Genetics and Molecular Biology ,General Environmental Science - Published
- 2019
49. Life-history theory predicts host behavioural responses to experimental brood parasitism
- Author
-
Peter Samaš, Tomáš Grim, Phillip Cassey, Jason Low, Mark E. Hauber, J. Rutila, and Michael G. Anderson
- Subjects
Avian clutch size ,Brood parasite ,Ecology ,Parasitism ,Zoology ,Biology ,Redstart ,biology.organism_classification ,Cuculus ,Bird egg ,Nest ,embryonic structures ,behavior and behavior mechanisms ,Animal Science and Zoology ,reproductive and urinary physiology ,Ecology, Evolution, Behavior and Systematics ,Black spot - Abstract
Life-history theory posits that the evolutionary responses of hosts to avian brood parasitism will be shaped by the extent of the fitness costs of parasitism. Previous modelling work predicted that hosts of more virulent parasites should eject foreign eggs, irrespective of clutch size, whereas hosts of less virulent parasites, with smaller clutch sizes, should desert (abandon) parasitized clutches and, with larger clutch sizes, should eject foreign eggs. Egg rejection behaviour of European blackbirds (Turdus merula) and song thrush (T. philomelos) in their introduced range in New Zealand was induced by manipulating the colour of one of the birds’ own eggs. We also used parallel experimental manipulations in the common redstart (Phoenicurus phoenicurus), a regular host species with a large clutch size which pays a moderate cost when parasitized by the common cuckoo (Cuculus canorus). In all three species, eggs coloured entirely black were more often rejected than eggs coloured with black spots but with the rest of the background colour left visible. Rejections of black eggs occurred mainly through nest desertion in blackbirds, which have smaller clutch sizes, and mainly through egg ejection in song thrush, which have larger clutch sizes. As predicted, redstarts mostly ejected black eggs. Alternative egg rejection behaviours may have evolved in response to differently virulent brood parasitism across these species. For example, in the absence of interspecific parasitism in both their native and introduced ranges, selection by low-cost intraspecific brood parasitism may explain the experimentally-induced behavioural differences in egg rejection in blackbirds, with smaller clutch sizes, versus song thrushes, with larger clutch sizes. Such experimental approaches, informed by life-history theory
- Published
- 2013
50. Ecological predictors of reduced avian reproductive investment in the southern hemisphere
- Author
-
Phillip Cassey, Tomáš Grim, Mark E. Hauber, Karl L. Evans, Peter Samaš, and Karel Weidinger
- Subjects
Avian clutch size ,Ecology ,media_common.quotation_subject ,Longevity ,Seasonality ,Biology ,medicine.disease ,Population density ,Predation ,Nest ,Spatial ecology ,medicine ,Southern Hemisphere ,Ecology, Evolution, Behavior and Systematics ,media_common - Abstract
Despite intensive research, the factors driving spatial patterns in life-history traits remain poorly understood. One of the most frequently documented, and paradoxically, least understood patterns, is the latitudinal gradient of increasing avian clutch size at higher latitudes. Th ese gradients are less marked in the southern hemisphere, thus clutch sizes tend to be smaller at southern latitudes than at equivalent northern ones. We exploited a natural experiment provided by the introduction of European passerines to New Zealand (NZ) to test three widely proposed ecological drivers of this pattern, i.e. the nest predation, Ashmole ’ s seasonality, and the breeding density hypotheses. We focus on the blackbird Turdus merula and the song thrush T. philomelos as founder eff ects do not have a major infl uence on the reproductive traits of their introduced populations. Both species laid smaller clutches in NZ than in Europe. Th ese reductions had stabilised within one hundred years and were not associated with a compensatory increase in investment in individual off spring by laying larger eggs. In contrast to the nest predation hypothesis, daily nest predation rates were lower in NZ than in Europe. Smaller southern hemisphere clutches were associated with higher conspecifi c population densities and a relaxation of seasonal clutch size trends. Th ese fi ndings thus provide some support for both Ashmole ’ s seasonality and the breeding density hypotheses. Analyses across 11 European passerines introduced to NZ suggest, however, that neither of these hypotheses provide general explanations of smaller clutches in the southern hemisphere. We suggest that reduced seasonality and lower nest predation promote increased breeding densities and adult survival in the southern hemisphere. Th e later may drive smaller southern clutch sizes by generating spatial variation in the outcome of the trade-off between reproductive investment and longevity.
- Published
- 2013
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