Search

The intensive rice cultivation area in northwestern Italy hosts the largest surface of rice paddies in Europe, and it is valued as a substantial habitat for aquatic biodiversity, with the paddies acting as a surrogate for the lost natural wetlands. The extent of submerged paddies strictly depends on crop management practices: in this framework, the recent diffusion of rice seeding in dry conditions has led to a reduction of flooded surfaces during spring and could have contributed to the observed decline of the populations of some waterbird species that exploit rice fields as foraging habitat. In order to test the existence and magnitude of a decreasing trend in the extent of submerged rice paddies during the rice-sowing period, MODIS remotely-sensed data were used to estimate the extent of the average flooded surface and the proportion of flooded rice fields in the years 2000-2016 during the nesting period of waterbirds. A general reduction of flooded rice fields during the rice-sowing season was observed, averaging -0.86 ± 0.20% per year (p-value < 0.01). Overall, the loss in submerged surface area during the sowing season reached 44% of the original extent in 2016, with a peak of 78% in the sub-districts to the east of the Ticino River. Results highlight the usefulness of remote sensing data and techniques to map and monitor water dynamics within rice cropping systems. These techniques could be of key importance to analyze the effects at the regional scale of the recent increase of dry-seeded rice cultivations on watershed recharge and water runoff and to interpret the decline of breeding waterbirds via a loss of foraging habitat. [ABSTRACT FROM AUTHOR]

This study provided the first hand data of trace elements into fish muscles (N = 65) collected from river Chenab in Pakistan during 2013, using inductively coupled plasma mass spectrometry (ICP-MS). We monitored the health risk associated with consumption of contaminated fish of river Chenab, by the local population. The mean concentrations (μg/g, wet weight), in descending order were: Zn (35.5–54.4), Cu (1.38–4.57), Mn (2.43–4.5), As (0.23–1.21), Cr (0.21–0.67), Ni (0.14–0.34), Pb (0.14–0.31), Co (0.09–0.12), Cd (0.07–0.12) with higher concentration to be observed in the herbivore fish species (i.e., Cirrhinus reba and Catla catla ). The levels of trace elements in different fish species found in this study were compared with similar data worldwide, and with the international standards for consumption. The concentration (μg/g) of arsenic in many cases (>65%) exceeded the FAO/WHO expert committee on food additives permissible limits. From the human health point of view, this study highlights that the local inhabitants, (i.e., fisher folk communities and population frequently consuming fish at about 100 g/day) along the river Chenab are exposed chronically to arsenic pollution with carcinogenic (10 −4 to 10 −6 ) and non-carcinogenic (THQ>1) risks, especially from the intake of Cirrhinus reba . [ABSTRACT FROM AUTHOR]

An annotated check-list of the bird species known to occur in the Novara province (1,340 km2) updated at 31st December 2016 is provided. Valuable information has been recently collected by regular monitoring activities in the field, most of which occurred in the period 2009-2016. In addition, ornithological literature has been reviewed, in several cases going back to the XIX century. Overall, 304 bird species have been recorded in the area since 1860: 135 of them have certainly or probably bred after year 2000, 85 are of community interest (included in Annex I of Birds Directive of European Union), 116 are SPEC - Species of European Conservation Concern according to BirdLife International and 53 are included in the European Red List of Birds. The area is of significant importance for several breeding species of conservation concern, including Egretta garzetta (650-1,100 nests), Nycticorax nycticorax (200-300 nests), Botaurus stellaris (5-7 singing males), Ciconia nigra (1-2 pairs), Ciconia ciconia (4-6 pairs), Himantopus himantopus (300-500 pairs), Vanellus vanellus (500-600 pairs), Columba oenas (20-30 pairs), and for migratory species such as Philomachus pugnax (5,000-7,000 individuals) and Tringa glareola (500-1,500 individuals). In the last few years (2009-2016) are worthy to note: the first breeding records of Ardea alba, Galerida cristata and Lullula arborea; the first records of Burhinus oedicnemus and Chlidonias niger during breeding season after decades of absence; the expansion of Dryocopus martius in hilly and lowland woody areas. [ABSTRACT FROM AUTHOR]

Prey–predator interactions are plastic behaviours shown by both players, which constantly modify their decisions depending on physiological conditions and ecological context. We investigated whether the behavioural response to repeated simulated predatory attacks varied between adult males of the common wall lizard, Podarcis muralis , inhabiting environments characterized by different degrees of human presence. Our aim was to detect possible effects of urbanization on antipredator responses, in terms of activity, time spent hidden in refuges and habituation. Moreover, since this lizard species exhibits intrapopulation colour polymorphism, we looked for the occurrence of possible correlations between antipredator strategy and individual ventral coloration. We found that urban lizards spent less time in their refuge after predatory attacks and decreased successive hiding times faster than rural lizards, suggesting different wariness towards a potential predator. Irrespective of population, yellow lizards gradually spent less time in the refuge before appearing and emerging outside than the other two morphs. Conversely, red lizards showed progressively longer appearance and emergence times after successive tests, suggesting a growing sensitization to the potential threat of a predatory attack. In conclusion, our study showed the occurrence of different levels of behavioural plasticity in common wall lizard's antipredator response: the population level, depending on ecological context, here different degrees of exposure to human disturbance, and the individual level, which suggests the occurrence of morph-specific antipredator strategies. Thus, using a lizard species as a model, we shed light on two key points of evolutionary ecology concerning both the antipredator response and the factors driving the maintenance of intraspecific polymorphism. [ABSTRACT FROM AUTHOR]

Recent changes in rice crop management within Northern Italy rice district led to a reduction of seeding in flooding condition, which may have an impact on reservoir water management and on the animal and plant communities that depend on the flooded paddies. Therefore, monitoring and quantifying the spatial and temporal variability of water presence in paddy fields is becoming important. In this study we present a method to estimate dynamics of presence of standing water (i.e. fraction of flooded area) in rice fields using MODIS data. First, we produced high resolution water presence maps from Landsat by thresholding the Normalised Difference Flood Index (NDFI) made: we made it by comparing five Landsat 8 images with field-obtained information about rice field status and water presence. Using these data we developed an empirical model to estimate the flooding fraction of each MODIS cell. Finally we validated the MODIS-based flooding maps with both Landsat and ground information. Results showed a good predictability of water surface from Landsat (OA = 92%) and a robust usability of MODIS data to predict water fraction (R 2 = 0.73, EF = 0.57, RMSE = 0.13 at 1 × 1 km resolution). Analysis showed that the predictive ability of the model decreases with the greening up of rice, so we used NDVI to automatically discriminate estimations for inaccurate cells in order to provide the water maps with a reliability flag. Results demonstrate that it is possible to monitor water dynamics in rice paddies using moderate resolution multispectral satellite data. The achievement is a proof of concept for the analysis of MODIS archives to investigate irrigation dynamics in the last 15 years to retrieve information for ecological and hydrological studies. [ABSTRACT FROM AUTHOR]

The rapid development of innovative molecular tools for characterizing biodiversity is leading to an extensive and sometimes unexpected renovation of taxonomic classifications. Particularly, for species having allopatric or parapatric distributions or resulting from recent speciation processes, the absence of clear phenotypic differentiation may hinder the recognition of closely related taxa, while intraspecific polymorphism may be confused with the presence of more than one single species. In the present work, we apply different phylogenetic methods in order to infer relationships within the genus Anatololacerta , and to assess the taxonomy of this morphologically diversified group of lizards endemic to western and southern Anatolia and some neighboring Aegean islands. According to morphology, three species have been recognized ( Anatololacerta anatolica , A. oertzeni and A. danfordi ) as well as several subspecies, but small variation at immunological markers led some authors to join all the populations into one single taxon, A. danfordi . By selecting both mitochondrial and nuclear informative markers, we tested the effectiveness of classical “gene tree” (i.e. Bayesian Inference) vs. innovative (i.e. coalescent-based) “species tree” methods in resolving the Anatololacerta taxonomic enigma, as a case in point for similar studies on species complexes resulting from non-obvious and cryptic diversification patterns. According to our results, the gene tree method failed in resolving phylogenetic relationships among clades, whereas the multi-locus species tree approach, coupled with species delimitation methods, allowed the identification of four well distinct species. These species probably diversified in different allopatric refugia located in southern and western Anatolia, where isolated populations may have persisted during Pleistocene glacial cycles. [ABSTRACT FROM AUTHOR]

Molt and ecdysis are costly activities crucial to several animals. Most birds completely molt their plumage once per year. The diverse energy and aerodynamic costs of molt are expected to shape the evolution of molt schedules and rate of feather renewal. Differences in molt strategies are also predicted between the sexes because of sex-related variation in fitness payoffs of rapid and early feather renewal. Feathers show barring patterns that reflect daily growth pulses. Ptilochronological analysis of growth bar width (GBW) reflecting condition-dependent feather growth rate can provide important, though overlooked information on molt strategies, and on the effects of body condition on feather renewal and subsequent migration or breeding. In this study of migratory Barn Swallows ( Hirundo rustica) wintering in Nigeria, for the first time we analyzed sex-related variation in molt schedules and feather growth rate using molecular sexing. We found no sex difference in molt schedules but faster feather growth in females. Hence, protandry in arrival of swallows to European breeding grounds does not depend on sex-specific timing of molt or feather renewal rate. Individuals with advanced molt had larger GBW and muscle mass, suggesting that individuals in good condition complete molt earlier thanks to faster feather growth. Arrival date on the breeding areas may thus reliably signal male quality, if molt completion constrains migration. Finally, the frequency of low GBW values among wintering males was larger than during breeding in swallows that winter in Nigeria, suggesting selection against low GBW. This study provides the first unequivocal data on sex-related variation in molt schedules in a species with no discrete sexual dimorphism, and emphasizes the potential of ptilochronology in ecological-evolutionary studies, as it shows that feather growth rate covaries with timing of molt but may not mediate protandrous migration. [ABSTRACT FROM AUTHOR]

Theoretical models predict that the outcome of dyadic agonistic encounters between males is influenced by resource-holding potential, resource value, and intrinsic aggressiveness of contestants. Moreover, in territorial disputes residents enjoy a further obvious competitive advantage from the residency itself, owing to the intimate familiarity with their territory. Costs of physical combats are, however, dramatically high in many instances. Thus, signals reliably reflecting fighting ability of the opponents could easily evolve in order to reduce these costs. For example, variation in color morph in polymorphic species has been associated with dominance in several case studies. In this study, we staged asymmetric resident-intruder encounters in males of the common wall lizard Podarcis muralis, a species showing three discrete morphs (white, yellow, and red) to investigate the effects of asymmetries in color morph, residency, and size between contestants on the outcome of territorial contests. We collected aggression data by presenting each resident male with three intruders of different color morph, in three consecutive tests conducted in different days, and videotaping their interactions. The results showed that simple rules such as residency and body size differences could determine the outcome of agonistic interactions: residents were more aggressive than intruders, and larger males were competitively superior to smaller males. However, we did not find any effect of color on male aggression or fighting success, suggesting that color polymorphism in this species is not a signal of status or fighting ability in intermale conflicts. Aggr. Behav. 35:274–283, 2009. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Sperm competition models predict that males should adjust their sperm expenditure according to the risk and intensity of sperm competition, increasing it when competing with at least one other ejaculate and decreasing it when the number of competing ejaculates rises above two. However, when the raffle to fertilize eggs is strongly loaded due to sperm removal by subsequent rivals, it could be hypothesized that first-mating males progressively decrease their sperm expenditure and/or defer copulation with an increasing number of nearby competitors. Here, by varying experimentally the number of competitors around a mating pair, we analysed mating behaviour of both sexes and sperm expenditure in relation to variation in the immediate risk of sperm competition in the freshwater crayfish Austropotamobius italicus, a species where males remove all or part and feed on sperm laid by previous mating males. We found that male mating behaviour varied significantly with increasing number of rivals, because interactions between focal males and competitors, as well as male refusals to copulate, increased with number of the latter. As a consequence, the probability to reach an effective copulation decreased with increasing number of competitors. However, males released similar amounts of sperm independently of the number of surrounding competitors. Thus, the observed lack of variation in sperm expenditure in relation to the number of surrounding rivals suggests that freshwater crayfish males are unable to adjust the size of their ejaculates to short-term variation in the immediate risk of sperm competition. [ABSTRACT FROM AUTHOR]

The ‘heterospecific attraction hypothesis’ (HAH) has been proposed to describe interactions between migrant and resident birds where migrants may indirectly select habitats using the presence/absence of residents. This hypothesis might be extended to other taxa, such as amphibians, which migrate yearly to breeding sites, sharing them with other species. However, the ability of amphibians to be cue-users is not quite obvious as for birds, and must be assessed first. Therefore, in this study we investigated how smooth newts, Lissotriton vulgaris, oriented facing two known species (the common toad, Bufo bufo, and the green toad, Pseudoepidalea viridis) and whether they oriented preferentially towards the calls of species that indicate the more suitable pond for breeding (B. bufo). Newts showed positive phonotactic responses for both species but clearly oriented towards B. bufo when the playbacks of the two toads were presented simultaneously. Our results support the idea that the ‘HAH’ might be extended to other taxa than birds. [Copyright &y& Elsevier]

Abstract: Eggs of vertebrates contain steroid hormones of maternal origin that may influence offspring performance. Recently, it has been shown that glucocorticoids, which are the main hormones mediating the stress response in vertebrates, are transmitted from the mother to the egg in birds. In addition, mothers with experimentally elevated corticosterone levels lay eggs with larger concentrations of the hormone, which produce slow growing offspring with high activity of the hypothalamo–adrenal axis under acute stress. However, the effects and function of transfer of maternal corticosterone to the eggs are largely unknown. In the present study, we injected corticosterone in freshly laid eggs of yellow-legged gulls (Larus michahellis), thus increasing the concentration of the hormone within its natural range of variation, and analyzed the effect of manipulation on behavioral, morphological, and immune traits of the offspring in the wild. Eggs injected with corticosterone had similar hatching success to controls, but hatched later. Mass loss during incubation was greater for corticosterone-treated eggs, except for the last laid ones. Corticosterone injection reduced rate and loudness of late embryonic vocalizations and the intensity of chick begging display. Tonic immobility response, reflecting innate fearfulness, was unaffected by hormone treatment. Elevated egg corticosterone concentrations depressed T-cell-mediated immunity but had no detectable effects on humoral immune response to a novel antigen, viability at day 10, or growth. Present results suggest that egg corticosterone can affect the behavior and immunity of offspring in birds and disclose a mechanism mediating early maternal effects whereby stress experienced by females may negatively translate to offspring phenotypic quality. [Copyright &y& Elsevier]

Citizen science initiatives have been increasingly used by researchers as a source of occurrence data to model the distribution of alien species. Since citizen science presence-only data suffer from some fundamental issues, efforts have been made to combine these data with those provided by scientifically structured surveys. Surprisingly, only a few studies proposing data integration evaluated the contribution of this process to the effective sampling of species' environmental niches and, consequently, its effect on model predictions on new time intervals. We relied on niche overlap analyses, machine learning classification algorithms and ecological niche models to compare the ability of data from citizen science and scientific surveys, along with their integration, in capturing the realized niche of 13 invasive alien species in Italy. Moreover, we assessed differences in current and future invasion risk predicted by each data set under multiple global change scenarios. We showed that data from citizen science and scientific surveys captured similar species niches though highlighting exclusive portions associated with clearly identifiable environmental conditions. In terrestrial species, citizen science data granted the highest gain in environmental space to the pooled niches, determining an increased future biological invasion risk. A few aquatic species modelled at the regional scale reported a net loss in the pooled niches compared to their scientific survey niches, suggesting that citizen science data may also lead to contraction in pooled niches. For these species, models predicted a lower future biological invasion risk. These findings indicate that citizen science data may represent a valuable contribution to predicting future spread of invasive alien species, especially within national-scale programmes. At the same time, citizen science data collected on species poorly known to citizen scientists, or in strictly local contexts, may strongly affect the niche quantification of these taxa and the prediction of their future biological invasion risk., (© 2023 John Wiley & Sons Ltd.)

Colonial waterbirds, a major biodiversity element occurring in the core of ultra-anthropized Europe, are ideal indicators of the wellness of inland wetlands. Nonetheless, there is a critical knowledge gap in their trend and population status. We present an uninterrupted 47 years-long dataset of the breeding populations of 12 species of colonial waterbirds (Ardeidae, Phalacrocoracidae, Plataleidae, Threskiornitidae) throughout a 58,000 km 2 agricultural region in the higher Po basin (NW Italy). A trained team of collaborators censused with standardized field techniques the number of nests of each species at 419 colonies in the 1972-2018 period, summing up a total of 236,316 records. Data cleaning and standardization were performed for each census year, ensuring robust and consistent data. This dataset is among the largest ever collected for a guild of European vertebrates. It has already been used to describe the factors influencing population trends, and still offers opportunities to explore a wide range of key ecological processes such as biological invasions, global change consequences and biodiversity impact of agricultural practices., (© 2023. The Author(s).)

Local recruitment and immigration play an important part in the dynamics and growth of animal populations. However, their estimation and incorporation into open population models is, in most cases, problematic. We studied factors affecting the growth of a recently established colony of Eurasian spoonbill (Platalea leucorodia) and assessed the contribution of local recruits, i.e. birds born in the colony, and immigrants, i.e. birds of unknown origin, to colony growth. We applied an integrated population model that accounts for uncertainty in breeding state assignment and merges population surveys, local fecundity and individual longitudinal data of breeding and non-breeding birds, to estimate demographic rates and the relative role of recruitment and immigration in driving the local dynamics. We also used this analytical framework to assess the degree of support for the 'performance-based' and 'conspecific attraction' hypotheses as possible mechanisms of colony growth. Among the demographic rates, only immigration was positively and significantly correlated with population growth rate. In addition, the number of immigrants settling in the colony was positively correlated with colony size in the previous and current year, but was not correlated with fecundity of the previous year. Our results suggest that the variation in immigration affected colony dynamics and that conspecific attraction likely triggered the relevant role of immigration in the growth of a recently formed waterbird colony, supporting the need of including immigration in population analysis., (© 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.)

We investigated selected chlorinated pollutants (β-HCH, γ-HCH, DDDs, DDEs, o,p'-DDT, p,p'-DDT, heptachlor, aldrin, dieldrin, and endrin) in the Lahore and the Sialkot districts of Pakistan, using eggs of cattle egret (Bubulcus ibis) collected during May and June 2007. The pollutant with highest level and frequency was ΣDDT, followed by β-HCH, γ-HCH, heptachlor, aldrin, dieldrin, and endrin in descending order. The concentration(s) were significantly higher in Sialkot heronry for all the pollutants (except p,p'-DDT) than in Lahore. The values for DDTs, β-HCH, γ-HCH, and heptachlor were significantly higher (p < 0.05) in the egg(s) than in sediment(s) and in the chicks' diet, due to biomagnification. Among DDTs analogues, p,p'-DDD was the major contaminant with >60 % of total DDT burden, reflecting the widespread aged as well as recent use of DDT as well as anaerobic degradation (DDD/DDE > 1 in many cases) in the nearby paddy soils. In few samples, p,p'-DDT/(DDD + DDE) > 0.5 suggested the recent emission patterns from surrounding contaminated areas of demolished DDT units and obsolete pesticide stores. The higher levels of HCHs (i.e., β-HCH) in the samples collected from Sialkot indicate exposure from long-term agricultural use. Overall, concentrations of all studied POPs were less than the threshold levels known to affect reproduction. Nevertheless, total DDTs and/or HCHs burdens in some eggs contained concentrations of greater than what would educe adverse effects on birds. This is among few studies on OCPs exposure to avian species, which provide the evidence of Pakistan's contribution toward the Global POPs emission.

Male and female offspring can differ in their susceptibility to pre-natal (e.g. egg quality) and post-natal (e.g. sib-sib competition) conditions, and parents can therefore increase their individual fitness by adjusting these maternal effects according to offspring sex. In birds, egg mass and laying/hatching order are the main determinants of offspring viability, but these effects can act differently on each sex. In a previous study, relatively large last-laid (c-)eggs of yellow-legged gulls (Larus michahellis) were more likely to carry a female embryo. This suggests compensatory allocation of maternal resources to daughters from c-eggs, which suffer reduced viability. In the present study, we supplemented yellow-legged gulls with food during the laying period to experimentally test whether their nutritional conditions were responsible for the observed covariation between c-egg sex and mass. As predicted, food supplementation enhanced female c-eggs' mass more than that of male c-eggs. Thus, this experiment indicates that mothers strategically allocated their resources to c-eggs, possibly in order to compensate for the larger susceptibility of daughters to hatching (and laying) order. The results also suggested that mothers decided on resource allocation depending on the sex of already ovulated c-eggs, rather than ovulating ova of either sex depending on food availability.

Maternal hormones in vertebrate eggs can mediate important forms of maternal effects. However, the function of hormone transfer to the eggs is still debated, especially because long-term fitness consequences have been little studied. We investigated the effect of prenatal exposure to physiologically elevated yolk testosterone (T) levels on reproduction of female pheasants (Phasianus colchicus) in captivity. We found that females hatching from T-injected eggs (T-females) had a lower egg-laying rate than controls, and their eggs were more frequently infertile than those laid by control females. There were no effects of prenatal maternal treatment on egg size and yolk T concentration, but eggs carrying a female embryo laid by T-females had smaller yolks than eggs with a male embryo, while there was no sex difference in yolk size among the eggs laid by control females. Progeny sex ratio was unaffected by maternal treatment. These findings suggest that the transfer of high androgen levels to the eggs by the mother is constrained by complex trade-offs between direct effects on her daughters' reproduction and by trans-generational differential consequences on male and female descendants.

Females may invest more in reproduction if they acquire mates of high phenotypic quality, because offspring sired by preferred partners may be fitter than offspring sired by non-preferred ones. In this study, we tested the differential maternal allocation hypothesis in the freshwater crayfish, Austropotamobius italicus, by means of a pairing experiment aimed at evaluating the effects of specific male traits (body size, chelae size and chelae asymmetry) on female primary reproductive effort. Our results showed that females laid larger but fewer eggs for relatively small-sized, large-clawed males, and smaller but more numerous eggs for relatively large-sized, small-clawed males. Chelae asymmetry had no effects on female reproductive investment. While the ultimate consequences of this pattern of female allocation remain unclear, females were nevertheless able to adjust their primary reproductive effort in relation to mate characteristics in a species where inter-male competition and sexual coercion may mask or obscure their sexual preferences. In addition, our results suggest that female allocation may differentially affect male characters, thus promoting a trade-off between the expression of different male traits.