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Background: Methods involving the analysis of nucleic acids have become widespread in the fields of traditional biology and ecology, however the storage and transport of samples collected in the field to the laboratory in such a manner to allow purification of intact nucleic acids can prove problematical. Results: FTA databasing paper is widely used in human forensic analysis for the storage of biological samples and for purification of nucleic acids. The possible uses of FTA databasing paper in the purification of DNA from samples of wildlife origin were examined, with particular reference to problems expected due to the nature of samples of wildlife origin. The processing of blood and tissue samples, the possibility of excess DNA in blood samples due to nucleated erythrocytes, and the analysis of degraded samples were all examined, as was the question of long term storage of blood samples on FTA paper. Examples of the end use of the purified DNA are given for all protocols and the rationale behind the processing procedures is also explained to allow the end user to adjust the protocols as required. Conclusions: FTA paper is eminently suitable for collection of, and purification of nucleic acids from, biological samples from a wide range of wildlife species. This technology makes the collection and storage of such samples much simpler. [ABSTRACT FROM AUTHOR]

Background: The rapid expansion in the availability of genome and DNA sequence information has opened up new possibilities for the development of methods for detecting free-living protozoa in environmental samples. The protozoan Blepharisma japonicum was used to investigate a rapid and simple detection system based on polymerase chain reaction amplification (PCR) from organisms immobilised on FTA paper. Results: Using primers designed from the a-tubulin genes of Blepharisma, specific and sensitive detection to the equivalent of a single Blepharisma cell could be achieved. Similar detection levels were found using water samples, containing Blepharisma, which were dried onto Whatman FTA paper. Conclusion: This system has potential as a sensitive convenient detection system for Blepharisma and could be applied to other protozoan organisms. [ABSTRACT FROM AUTHOR]

Background: Social behaviour has been linked to hypotheses explaining multiannual population cycles of small rodents. In this paper we aimed to test empirically that the degree of space sharing among adult breeding female voles is higher during the increase phase than in the crash phase, and that the degree of sociality is positively related to population growth rate as suggested by Lambin and Krebs (Oikos 61:126–132, 1991) and Andreassen et al. (Oikos 122:507–515, 2013). We followed 24 natural bank vole Myodes glareolus populations over an area of 113 km2 by monthly live trapping throughout a complete population cycle of three summers and two winters. Results: Using spatially explicit capture-recapture models, we modelled the overlap in adult female home ranges and total population growth rate per season. We identified an increase phase before and during the peak density observation and a crash phase following the peak. Female home range overlap were seasonal- and phase-dependent, while population growth rate was associated with season and female home range overlap. High female home range overlap in the increase phase corresponded to a high population growth rate. Conclusions: We suggest that intrinsic social behaviour plays a key role in the increase phase of vole population cycles, as social behaviour leads to an increased growth rate, whereas extrinsic factors (predation and/or food) initiate the crash phase. Our results are consistent with those of other studies in a variety of small rodent species. [ABSTRACT FROM AUTHOR]

Background: Natural history has a long tradition in the UK, dating back to before Charles Darwin. Developing from a principally amateur pursuit, natural history continues to attract both amateur and professional involvement. Within the context of citizen science and public engagement, we examine the motivations behind citizen participation in the national survey activities of the Open Air Laboratories (OPAL) programme, looking at: people's experiences of the surveys as 'project-based leisure'; their motivations for taking part and barriers to continued participation; where they feature on our continuum of engagement; and whether participation in an OPAL survey facilitated their movement between categories along this continuum. The paper focuses on a less-expected but very significant outcome regarding the participation of already-engaged amateur naturalists in citizen science. Results: Our main findings relate to: first, how committed amateur naturalists (already-engaged) have also enjoyed contributing to OPAL and the need to respect and work with their interest to encourage broader and deeper involvement; and second, how new (previously-unengaged) and relatively new participants (casually-engaged) have gained confidence, renewed their interests, refocussed their activities and/or gained validation from participation in OPAL. Overall, we argue that engagement with and enthusiasm for the scientific process is a motivation shared by citizens who, prior to participating in the OPAL surveys, were previously-unengaged, casually-engaged or already-engaged in natural history activities. Conclusions: Citizen science has largely been written about by professional scientists for professional scientists interested in developing a project of their own. This study offers a qualitative example of how citizen science can be meaningful to participants beyond what might appear to be a public engagement data collection exercise. [ABSTRACT FROM AUTHOR]

Background: Different methods have been used to map species and habitat distributions. In this paper, similaritybased reasoning--a methodological approach that has received less attention--was applied to estimate the distribution and coverage of Dasiphora fruticosa for the region in the Baltic states where grows the most abundant population of this species. Methods: Field observations, after thinning to at least 50 m interval, included 1480 coverage estimations in the species presence locations and 8317 absence locations. Species coverage for the 750 km2 of directly unobserved area was calculated using machine learning in the similarity-based prediction system Constud. Separate predictive sets of site features (e.g. land cover, soil type) and exemplar weights were calibrated for spatial partitions of the study area (probable presence region, unclear region, proved absence region). A modified version of the Gower's distance metric, as used in Constud, is described. Results: The resulting maps depicted the predicted coverage, the certainty of decision when predicting presence or absence, and the mean similarity to the exemplar locations used while predicting. Coverage prediction errors were smaller in the unclear partition--where the species was mostly absent--than in the probable presence partition, where coverage ranged from 0 to 90%. Conclusions: We call for methodological comparisons using the same data set. [ABSTRACT FROM AUTHOR]

Background: Human beings use plants for a multitude of purposes of which a prominent one across the globe is for their medicinal values. Medicinal plants serve as one of the major sources of income for high altitude inhabitants in the Himalaya, particularly in countries like Nepal, and Bhutan. People here harvest huge volumes of medicinal plants indiscriminately, risking their sustainability. This paper attempts to identify some of the priority medicinal plant species harvested in the wild and assess their ecological status for their judicious utilization, and to help provide policy guidance for possible domestication and support strategic conservation frameworks. Results: Out of the 16 priority species identified by the expert group, collectors' perception on ecological status of the priority species differed from survey findings. Chrysosplenium nudicaule (clumps) ranked as most threatened species followed by Corydalis dubia, and Meconopsis simplicifolia. Onosma hookeri, Corydalis crispa and Delphinium glaciale were some of the species ranked as threatened species followed by Halenia elliptica (not in priority list). Percent relative abundance showed irregular pattern of species distribution. High species evenness was recorded among Nardostachys grandiflora, Chrysosplenium nudicaule, Saussurea gossypiphora and Aconitum orochryseum with average species density of 8 plant m-2. Rhodiola crenulata, and Dactylorhiza hatagirea followed by Meconopsis horridula and Meconopsis simplicifolia were ranked as most threatened species with average species density of 0.4, 0.4, 5.6 and 6.0 plant m-2, respectively. The most abundant (common) species was Onosma hookeri (plant m-2). Species composition and density also differed with vegetation, altitude, slope and its aspects. Conclusion: Priority species identified by expert group were found vulnerable and patchy in distribution. Survey results and collectors' perceptions tally to an extent. Some of the species (Dactylorhiza hatagirea, Rhodiola crenulata, Meconopsis simplicifolia and Meconopsis horridula) were critically low in plant density with less than a plant per m² while Delphinium glaciale, Fritillaria delavayi and Aconitum orochryseum were confined to narrow altitude range. Collectors were aware that most species identified in priority list are threatened and existing harvesting plan are hardly implemented as it is not pragmatic. Moreover, major chunk of medicinal plants harvested remain unaccounted as illegal harvest and marketing seemed to occur across the borders. Policing and monitoring would continue to be a challenge given the rugged terrain and harsh climate. In-depth study and further monitoring of low density species is suggested to ensure its sustainability through long term strategy development. [ABSTRACT FROM AUTHOR]

Biodiversity informatics plays a central enabling role in the research community's efforts to address scientific conservation and sustainability issues. Great strides have been made in the past decade establishing a framework for sharing data, where taxonomy and systematics has been perceived as the most prominent discipline involved. To some extent this is inevitable, given the use of species names as the pivot around which information is organised. To address the urgent questions around conservation, land-use, environmental change, sustainability, food security and ecosystem services that are facing Governments worldwide, we need to understand how the ecosystem works. So, we need a systems approach to understanding biodiversity that moves significantly beyond taxonomy and species observations. Such an approach needs to look at the whole system to address species interactions, both with their environment and with other species. It is clear that some barriers to progress are sociological, basically persuading people to use the technological solutions that are already available. This is best addressed by developing more effective systems that deliver immediate benefit to the user, hiding the majority of the technology behind simple user interfaces. An infrastructure should be a space in which activities take place and, as such, should be effectively invisible. This community consultation paper positions the role of biodiversity informatics, for the next decade, presenting the actions needed to link the various biodiversity infrastructures invisibly and to facilitate understanding that can support both business and policy-makers. The community considers the goal in biodiversity informatics to be full integration of the biodiversity research community, including citizens' science, through a commonly-shared, sustainable e-infrastructure across all sub-disciplines that reliably serves science and society alike. [ABSTRACT FROM AUTHOR]

Background: An in depth understanding of mosquito breeding biology and factors regulating population sizes is fundamental for vector population control. This paper presents results from a survey of mosquito breeding habitats and the efficacy of neem chippings as a potential larvicide that can be integrated in mosquito control on Nyabondo Plateau in western Kenya. Results: Six main mosquito habitat types namely artificial ponds, abandoned fish ponds, active fish ponds, open drains, temporary pools and swamps were found in Nyabondo. Early anopheline instars were mainly recovered from temporary pools, artificial ponds and abandoned fish ponds. The mosquitoes collected were Anopheles gambiae sensu lato (35%), An. coustani (46%) and Culex spp (19%). Both early and late instar larvae of anopheline and culicine mosquitoes were more abundant in the controls than in the Bti and neem treated habitats. Within treated habitats, early instar anopheline mosquitoes were recovered more from habitats provided with neem and fish compared to Bti treated habitats. All treated habitats recorded higher numbers of early instar larvae than late instars or pupae, indicating that gravid female mosquitoes still oviposited within treated habitats. Conclusions: Neem chippings are a good tool for mosquito larval source management under field conditions. However, more research needs to be done to quantify the contribution of this tool to the overall mosquito borne disease transmission. [ABSTRACT FROM AUTHOR]

Background: The time varying flows of biomass and energy in tsetse (Glossina) can be examined through the construction of a dynamic mass-energy budget specific to these flies but such a budget depends on efficiencies of metabolic conversion which are unknown. These efficiencies of conversion determine the overall yields when food or storage tissue is converted into body tissue or into metabolic energy. A biochemical approach to the estimation of these efficiencies uses stoichiometry and a simplified description of tsetse metabolism to derive estimates of the yields, for a given amount of each substrate, of conversion product, by-products, and exchanged gases. This biochemical approach improves on estimates obtained through calorimetry because the stoichiometric calculations explicitly include the inefficiencies and costs of the reactions of conversion. However, the biochemical approach still overestimates the actual conversion efficiency because the approach ignores all the biological inefficiencies and costs such as the inefficiencies of leaky membranes and the costs of molecular transport, enzyme production, and cell growth. Results: This paper presents estimates of the net amounts of ATP, fat, or protein obtained by tsetse from a starting milligram of blood, and provides estimates of the net amounts of ATP formed from the catabolism of a milligram of fat along two separate pathways, one used for resting metabolism and one for flight. These estimates are derived from stoichiometric calculations constructed based on a detailed quantification of the composition of food and body tissue and on a description of the major metabolic pathways in tsetse simplified to single reaction sequences between substrates and products. The estimates include the expected amounts of uric acid formed, oxygen required, and carbon dioxide released during each conversion. The calculated estimates of uric acid egestion and of oxygen use compare favorably to published experimental measurements. Conclusion: This biochemical analysis provides reasonable first estimates of the conversion efficiencies for the major pathways used by tsetse metabolism. These results now enable a deeper analysis of tsetse ecology based on the construction of a dynamic mass-energy budget for tsetse and their populations. [ABSTRACT FROM AUTHOR]

Background: The raccoon (Procyon lotor) is an invasive, non-native species in Japan. Throughout the country, it causes significant agricultural damage and negatively affects native biodiversity. Most of the responsibility for raccoon management lies with local government, and there are still many challenges to be overcome. Although raccoon populations have not been eradicated, intensive control campaigns such as focus on the early stages of invasion have controlled raccoons in some regions. To improve the national management of raccoons, we conducted a survey on raccoon management systems in local government departments considered to solve the challenges recognized in many areas. During 2014 and 2015, we surveyed three different municipal departments about raccoon management measures. The semi-structured interview survey covered two topics: (1) the situation leading up to the current management system; (2) the current management system. Results: Our results describe the scope and methods used in raccoon management. The government staff managed raccoons using monitoring, employing a variety of methods, a range of budgets, and various role divisions. The management practices are similar in that they share a sense of taking precautions, collaborating with stakeholders, understanding that adequate methods must be used, and obtaining support from experts. Conclusions: Our case studies reveal the challenges in raccoon management faced by local government officers in regions with active control. The management systems and methods that we surveyed seemed to be effective in solving problems in both developed and undeveloped areas. [ABSTRACT FROM AUTHOR]

Background: Soil and microbial biomass stoichiometry plays an important role in understanding nutrient cycling in terrestrial ecosystems. However, studies on soil and microbial biomass stoichiometry in forests are rare. This study investigated the effect of tree species and topographic factors on the ecological stoichiometry of soil and soil microbial biomass. Methods: Three types of forest stands (Quercus variabilis, Larix principis-ruprechtii, and Cotinus coggygria Scop.) in the Beiru River basin of Funiu Mountain were analyzed in September 2018. Six slope positions (sunny bottom slope, sunny middle slope, sunny top slope, shady bottom slope, shady middle slope, and shady top slope) were selected, and the total number of sampling plots was 108. The stoichiometric indices of soil and microbial biomass were determined. Results: At a depth of 0–10 cm, the soil organic C contents in different stands followed the order of C. coggygria (27.7 ± 5.2 g/kg) > Q. variabilis (24.5 ± 4.9 g/kg) > L. principis-ruprechtii (20.8 ± 4.3 g/kg) (P < 0.05). The soil organic C contents at depths of 0–10 cm with different slope aspects and at different slope positions also showed significant differences (P < 0.05). The highest MBC content was observed at the slope bottom (1002 ± 157 mg/kg), whereas the lowest was observed at the slope top (641 ± 98.3 mg/kg). Redundancy analysis showed that the contribution of tree species to these differences was 57.1%, whereas that of topographical factors was 36.2%. Conclusions: Tree species more significantly affected soil nutrients and microbial biomass C, N and P than did topographic factors. [ABSTRACT FROM AUTHOR]

Background: So far, large numbers of studies investigating the microbiome have focused on gut microbiota and less have addressed the microbiome of the skin. Especially in avian taxa our understanding of the ecology and function of these bacteria remains incomplete. The involvement of skin bacteria in intra-specific communication has recently received attention, and has highlighted the need to understand what information is potentially being encoded in bacterial communities. Using next generation sequencing techniques, we characterised the skin microbiome of wild zebra finches, aiming to understand the impact of sex, age and group composition on skin bacteria communities. For this purpose, we sampled skin swabs from both sexes and two age classes (adults and nestlings) of 12 different zebra finch families and analysed the bacterial communities. Results: Using 16S rRNA sequencing we found no effect of age, sex and family on bacterial diversity (alpha diversity). However, when comparing the composition (beta diversity), we found that animals of social groups (families) harbour highly similar bacterial communities on their skin with respect to community composition. Within families, closely related individuals shared significantly more bacterial taxa than non-related animals. In addition, we found that age (adults vs. nestlings) affected bacterial composition. Finally, we found that spatial proximity of nest sites, and therefore individuals, correlated with the skin microbiota similarity. Conclusions: Birds harbour very diverse and complex bacterial assemblages on their skin. These bacterial communities are distinguishable and characteristic for intraspecific social groups. Our findings are indicative for a family-specific skin microbiome in wild zebra finches. Genetics and the (social) environment seem to be the influential factors shaping the complex bacterial communities. Bacterial communities associated with the skin have a potential to emit volatiles and therefore these communities may play a role in intraspecific social communication, e.g. via signalling social group membership. [ABSTRACT FROM AUTHOR]

Background: With the growth of economic benefits brought by Zanthoxylum bungeanum Maxim. and the increasing market demand, this species has been widely introduced and cultivated in China. It is important to scientifically select suitable areas for artificial planting and promotion, and to understand the status and potential of Z. bungeanum resources. Results: The maximum entropy (MaxEnt) model and ArcGIS technologies were used to analyze the climatic suitability of Z. bungeanum based on known distribution data, combined with environmental data in China. Z. bungeanum was mainly distributed in subtropical and mid-eastern warm temperate regions. The total suitable area (high and medium suitability) accounted for 32% of China's total land area, with high suitability areas composing larger percentage, reaching 1.93 × 106 km2. The suitable range (and optimum value) of the key environmental variables affecting the distribution of Z. bungeanum were the maximum temperature in February of 2.8–17.7 °C (10.4 °C), the maximum temperature in March of 8.6–21.4 °C (16.3 °C), the maximum temperature in December of 2.5–17.1 °C (9.9 °C), the maximum temperature in November of 7.7–22.2 °C (14.5 °C) and the mean temperature in March of 3.2–16.2 °C (12.0 °C). Conclusions: The model developed by MaxEnt was applicable to explore the environmental suitability of Z. bungeanum. [ABSTRACT FROM AUTHOR]

The seventh BMC Ecology competition attracted entries from talented ecologists from around the world. Together, they showcase the beauty and diversity of life on our planet as well as providing an insight into the biological interactions found in nature. This editorial celebrates the winning images as selected by the Editor of BMC Ecology and senior members of the journal's editorial board. Enjoy! [ABSTRACT FROM AUTHOR]

Background: In this multidisciplinary study we present soil chemical, phytochemical and GIS spatial patterning evidence that fairy circles studied in three separate locations of Namibia may be caused by Euphorbia species. Results: We show that matrix sand coated with E. damarana latex resulted in faster water-infiltration rates. GC-MS analyses revealed that soil from fairy circles and from under decomposing E. damarana plants are very similar in phytochemistry. E. damarana and E. gummifera extracts have a detrimental effect on bacteria isolated from the rhizosphere of Stipagrostis uniplumis and inhibit grass seed germination. Several compounds previously identified with antimicrobial and phytotoxic activity were also identified in E. gummifera. GIS analyses showed that perimeter sizes and spatial characteristics (Voronoi tessellations, distance to nearest neighbour ratio, pair correlation function and L-function) of fairy circles are similar to those of fairy circles co-occurring with E. damarana (northern Namibia), and with E. gummifera (southern Namibia). Historical aerial imagery showed that in a population of 406 E. gummifera plants, 134 were replaced by fairy circles over a 50-year period. And finally, by integrating rainfall, altitude and landcover in a GIS-based site suitability model, we predict where fairy circles should occur. The model largely agreed with the distribution of three Euphorbia species and resulted in the discovery of new locations of fairy circles, in the far southeast of Namibia and part of the Kalahari Desert of South Africa. Conclusions: It is proposed that the allelopathic, adhesive, hydrophobic and toxic latex of E. damarana, E. gummifera, and possibly other species like E. gregaria, is the cause of the fairy circles of Namibia in the areas investigated and possibly in all other areas as well. [ABSTRACT FROM AUTHOR]

Background: Temperate forest understorey vegetation poses an excellent study system to investigate whether increases in resource availability lead to an increase in plant species richness. Most sunlight is absorbed by the species-poor tree canopy, making the much more species-rich understorey species inhabit a severely resource-limited habitat. Additionally, the heterogeneity of light availability, resulting from management-moderated tree composition and age structure, may contribute to species coexistence. One would therefore expect that the diversity in the herb layer correlates positively with either the overall light availability, or the light heterogeneity, depending on whether resource availability or heterogeneity are more important drivers of diversity. To test this idea, we assessed variability of light conditions in 75 forest plots across three ecoregions with four different methods. Results: We correlated these data with vegetation relevés and found light availability to be strongly positively correlated with understorey plant species richness, as well as with understorey cover. Light variability (assessed with two approaches) within plots was positively correlated with transmittance, but did not improve the relationship further, suggesting that the main driver of species richness in this system is the overall resource availability. Two of the three beech-dominated regions exhibited near-identical effects of light transmittance, while the third, featuring pine alongside beech and thus with the longest gradient of transmittance and lowest species richness, displayed a weaker light response. Conclusions: While site conditions are certainly responsible for the trees selected by foresters, for the resulting forest structure, and for the differences in plant species pools, our results suggest that light transmittance is a strong mediating factor of understorey plant species richness. [ABSTRACT FROM AUTHOR]

Background: Competition within and between social groups determines access to resources and can be inferred from space use parameters that reflect depletion of food resources and competitive abilities of groups. Using location data from 1998 to 2017, we investigated within- and between-group competition in 12 groups of wild mountain gorillas (Gorilla beringei beringei). As within-group feeding competition is expected to increase with group size, an increase in group size is predicted to lead to an increase in the size of annual home ranges and core areas, but to a decrease in fidelity (reuse of an area). Due to asymmetries in competitive abilities, larger groups are expected to have higher exclusivity (degree of non-shared space) of annual home ranges and core areas than smaller groups. Results: We found evidence of within-group feeding competition based on a positive relationship between group size and both annual home range and core area size as well as a negative relationship between group size and core area fidelity. Additionally, fidelity of core areas was lower than of home ranges. Between-group competition was inferred from a trend for groups with more members and more males to have more exclusive home ranges and core areas. Lastly, annual core areas were largely mutually exclusive. Conclusions: Our study suggests that non-territorial, group-living animals can have highly dynamic, long-term avoidance-based spacing patterns, both temporally and spatially, to maintain annual core area exclusivity among groups while concurrently shifting these areas annually within overlapping home ranges to avoid resource depletion. Despite ranging in larger home ranges and core areas, larger groups were able to maintain more exclusive ranges than smaller groups, suggesting a competitive advantage for larger groups in between-group competition in a non-territorial species. Together, these findings contribute to understanding how social animals make behavioral adjustments to mitigate the effects of intraspecific competition. [ABSTRACT FROM AUTHOR]

Background: Manure and biochar soil amendments have shown many benefits to soil quality and crop productivity. This study aimed to reveal the effects of biochar and manure applications on soil fertility improvement and crop productivity in yellow cinnamon soil. Results: This study based on a 5-year field experiment. Four treatments were designed, included the control (CK), biochar amendment, manure amendment, and both biochar and manure amendment (BM). The results showed that: after five years, both biochar and manure treatment improved soil structure by increasing soil mean weight diameter (MWD), and soil water and nutrient supply was also increased by increasing the contents of water content, available potassium and available phosphorus. The productivity was also enhanced as wheat yield under the biochar, manure, and BM treatments increased by 3.59–11.32% compared with CK. In addition, biochar and manure treatment increased soil microbial biomass carbon (MBC) by > 15%, and soil total nematode abundance was significantly increased. Furthermore, the nematode community structure was significantly affected by biochar and manure treatment, dominant trophic group in CK was herbivores, but bacterivores were dominant in the biochar and manure treatments. The distribution of nematode genera was closely related to soil chemical properties and microbial biomass. Increases in the Shannon's diversity index, and decreases in the dominance index and summed maturity index after the 5-year treatment indicated a sustainable soil ecosystem after the biochar and manure applications. Conclusions: These findings indicate that biochar and manure result in better soil quality and increased productivity in yellow cinnamon soil. [ABSTRACT FROM AUTHOR]

Background: Species distribution models are commonly used tools to describe diversity patterns and support conservation measures. There is a wide range of approaches to developing SDMs, each highlighting different characteristics of both the data and the ecology of the species or assemblages represented by the data. Yet, signals of species co-occurrences in community data are usually ignored, due to the assumption that such structuring roles of species co-occurrences are limited to small spatial scales and require experimental studies to be detected. Here, our aim is to explore associations among marine sandy-bottom sediment inhabitants and test for the structuring effect of seagrass on co-occurrences among these species across a New Zealand intertidal sandflat, using a joint species distribution model (JSDM). Results: We ran a JSDM on a total of 27 macrobenthic species co-occurring in 300,000 m2 of sandflat. These species represented all major taxonomic groups, i.e. polychaetes, bivalves and crustaceans, collected in 400 sampling locations. A number of significant co-occurrences due to shared habitat preferences were present in vegetated areas, where negative and positive correlations were approximately equally common. A few species, among them the gastropods Cominella glandiformis and Notoacmea scapha, co-occurred randomly with other seagrass benthic inhabitants. Residual correlations were less apparent and mostly positive. In bare sand flats shared habitat preferences resulted in many significant co-occurrences of benthic species. Moreover, many negative and positive residual patterns between benthic species remained after accounting for habitat preferences. Some species occurring in both habitats showed similarities in their correlations, such as the polychaete Aglaophamus macroura, which shared habitat preferences with many other benthic species in both habitats, yet no residual correlations remained in either habitat. Conclusions: Firstly, analyses based on a latent variable approach to joint distributions stressed the structuring role of species co-occurrences beyond experimental scales. Secondly, results showed context dependent interactions, highlighted by species having more interconnected networks in New Zealand bare sediment sandflats than in seagrass meadows. These findings stress the critical importance of natural history to modelling, as well as incorporating ecological reality in SDMs. [ABSTRACT FROM AUTHOR]

Background: Migrant birds travel between their breeding areas and wintering grounds by alternating energetically and physiologically demanding flights with periods of rest and fuelling, so-called stopovers. An important intrinsic factor influencing the decision to resume migration is the amount of energy stores available for the next flight. Correlative studies with free-flying birds and experimental studies with caged birds have shown that the amount of energy stores affects the day-to-day, within-day and the directional decision of departure. The methodological advantages of both the correlative and experimental approach are combined when radio-tagging many individuals on the same day and subsequently determining the departure decisions at a high spatiotemporal resolution. Making use of such a quasi-experimental approach with an automated radio-tracking system at stopover, we studied the effect of energy stores on departure decisions and whether they vary between species of different migration strategies experiencing contrasting time constraints. For this, we chose a long-distance migrant, the common redstart (Phoenicurus phoenicurus), and a medium-distance migrant, the European robin (Erithacus rubecula), because the former has to travel at relatively higher speed to reach its wintering ground in a reasonable time at the expense of relatively higher energetic costs for travelling than the latter. Results: Common redstarts with higher energy stores were more likely to resume migration than their conspecifics with lower energy stores, whereas this pattern was absent in the European robins. The amount of energy stores significantly affected the timing of departure within the day, with large energy stores yielding early departures in both species. Departure directions from the stopover site during the first night after capture were oriented towards the seasonally appropriate direction but were not affected by variation in energy stores. Conclusions: We demonstrate the importance of variation in energy stores on the departure decisions and that it may affect species with different migration strategies dissimilarly in autumn. Nevertheless, knowledge of other intrinsic factors, such as feeding conditions, health status and physiological consequences of previous flights, is additionally required to better understand the departure decisions of migrants, as this is the key to providing an overall assessment of the decision-making process. [ABSTRACT FROM AUTHOR]

Background: Spatial conservation prioritisation (SCP) is a set of computational tools designed to support the efficient spatial allocation of priority areas for conservation actions, but it is subject to many sources of uncertainty which should be accounted for during the prioritisation process. We quantified the sensitivity of an SCP application (using software Zonation) to possible sources of uncertainty in data-poor situations, including the use of different surrogate options; correction for sampling bias; how to integrate connectivity; the choice of species distribution modelling (SDM) algorithm; how cells are removed from the landscape; and two methods of assigning weights to species (red-list status or prediction uncertainty). Further, we evaluated the effectiveness of the Egyptian protected areas for conservation, and spatially allocated the top priority sites for further on-the-ground evaluation as potential areas for protected areas expansion. Results: Focal taxon (butterflies, reptiles, and mammals), sampling bias, connectivity and the choice of SDM algorithm were the most sensitive parameters; collectively these reflect data quality issues. In contrast, cell removal rule and species weights contributed much less to overall variability. Using currently available species data, we found the current effectiveness of Egypt's protected areas for conserving fauna was low. Conclusions: For SCP to be useful, there is a lower limit on data quality, requiring data-poor countries to improve sampling strategies and data quality to obtain unbiased data for as many taxa as possible. Since our sensitivity analysis may not generalise, conservation planners should use sensitivity analyses more routinely, particularly relying on more than one combination of SDM algorithm and surrogate group, consider correction for sampling bias, and compare the spatial patterns of predicted priority sites using a variety of settings. The sensitivity of SCP to connectivity parameters means that the responses of each species to habitat loss are important knowledge gaps. [ABSTRACT FROM AUTHOR]

Background: Although behavioral unpredictability is widely described within-individual variability in behavior, its adaptive significance is little understood. Using a dynamic state variable model, this study investigated the conditions under which behavioral unpredictability (a component of within-individual variability) in foraging behavior is advantageous. The model considers a situation in which a forager forages for a fixed period, represented by discrete time steps. The outcome of foraging may change the level of a state (e.g., size and fat storage) of the forager at each time step, and variability in the foraging outcome is assumed to be positively correlated with behavioral unpredictability. The probability of death at each time step is influenced by the state at the same time step. Reproduction occurs after all the foraging steps and is influenced by the state level of a forager at the time of reproduction. According to the expected utility hypothesis, the relationship (e.g., curvature) between the state and fitness will determine the role of behavioral unpredictability. In the model, the relationship was obtained by using the backward iteration method for each foraging time step. Results: State-dependent mortality adds curvature to the relationship between the state and fitness, which makes the effect of behavioral unpredictability on fitness either positive or negative. This conclusion holds for any state-dependent mortality (i.e., as long as mortality is not independent of the state factor). Given that state-dependent mortality is commonly described, conditions that benefit behavioral unpredictability are likely also common. Conclusions: When mortality depends on a state that is influenced by behavior, conditions that favor behavioral unpredictability may become common. How behavioral unpredictability influences the variability of behavioral outcomes is as important as how it influences the expectation of behavioral outcomes when studying the adaptive significance of behavioral unpredictability. [ABSTRACT FROM AUTHOR]

Background: The monarch butterfly (Danaus plexippus) is a conspicuous insect that has experienced a drastic population decline over the past two decades. While there are several factors contributing to dwindling monarch populations, habitat loss is considered the most significant threat to monarchs. In the United States, loss of milkweed, particularly in the Midwest, has greatly reduced the available breeding habitat of monarchs. This has led to extensive efforts to conserve and restore milkweed resources throughout the Midwest. Recently, these research and conservation efforts have been expanded to include other important areas along the monarch's migratory path. Results: During the fall of 2018, we conducted surveys of monarch eggs and larvae through West Texas. We documented monarch and queen butterfly (Danaus gilippus) reproduction throughout the region and used the proportion of monarch and queen larva to estimate the number of monarch eggs. Peak egg densities for monarchs were as high as 0.78 per milkweed ramet after correction for the presence of queens. Despite our observations encompassing only a limited sample across one season, the peak monarch egg densities we observed exceeded published reports from when monarch populations were higher. Conclusions: To our knowledge, this is the first study to correct for the presence of queens when calculating the density of monarch eggs. This research also provides insight into monarch utilization of less well-known regions, such as West Texas, and highlights the need to expand the scope of monarch monitoring and conservation initiatives. While the importance of monarch research and conservation in the Midwest is unquestionable, more comprehensive efforts may identify new priorities in monarch conservation and lead to a more robust and effective overall strategy, particularly given the dynamic and rapidly changing global environment. [ABSTRACT FROM AUTHOR]

Background: Resolving the preferred prey items and dietary proportions of leopard seals is central to understanding food-web dynamics in the rapidly-warming Antarctic Peninsula region. Previous studies have identified a wide range of prey items; however, due to anecdotal or otherwise limited information, leopard seal diets remain unresolved by seal sex, individual, body size, region, and season. Over the 2013, 2014, and 2017 field seasons we collected scat, tissue samples (red blood cells and plasma; n = 23) for stable isotope analyses, and previously-reported animal-borne video from 19 adult leopard seals foraging near mesopredator breeding colonies at Cape Shirreff, Livingston Island. We summarized a priori diet information from scat and video analysis and applied a three-isotope (δ13C, δ15N, δ34S), four-source (fish, fur seal, krill, penguin) Bayesian mixing model to examine temporal variability in both prey sources and leopard seal tissues. Results: The austral spring diets of males and females focused on Antarctic krill (31.7–38.0%), notothen fish (31.6–36.5%), and penguin (24.4–26.9%) and were consistent across all 3 years. Several lines of evidence suggest the transition to summer foraging was distinct for males and females. Female diets transitioned rapidly to higher δ15N values (+2.1‰), indicating increased consumption of penguin (29.5–46.2%) and energy-dense Antarctic fur seal pup (21.3–37.6%). Conclusions: The seasonal increase in leopard seal δ15N values, and thus fur seal in their diet, was predictably related to larger body size; it may also be forcing reductions to the largest Antarctic fur seal colony in the Antarctic Peninsula. Our ensemble sampling approach reduces historical biases in monitoring marine apex predator diets. Further, our results are necessary to best inform regional fisheries management planning. [ABSTRACT FROM AUTHOR]

Background: The long-tailed duck (Clangula hyemalis) was categorized as ´Vulnerable' by the IUCN after a study revealed a rapid wintering population decline of 65% between 1992–1993 and 2007–2009 in the Baltic Sea. As knowledge about the European long-tailed duck's life cycle and movement ecology is limited, we investigate its year-round spatiotemporal distribution patterns. Specifically, we aimed to identify the wintering grounds, timing of migration and staging of this population via light-level geolocation. Results: Of the 48 female long-tailed ducks tagged on Kolguev Island (western Russian Arctic), 19 were recaptured to obtain data. After breeding and moulting at freshwater lakes, ducks went out to sea around Kolguev Island and to marine waters ranging from the White Sea to Novaya Zemlya Archipelago for 33 ± 10 days. After a rapid autumn migration, 18 of 19 birds spent their winter in the Baltic Sea and one bird in the White Sea, where they stayed for 212 ± 3 days. There, they used areas known to host long-tailed ducks, but areas differed among individuals. After a rapid spring migration in mid-May, the birds spent 23 ± 3 days at sea in coastal areas between the White Sea and Kolguev Island, before returning to their freshwater breeding habitats in June. Conclusions: The Baltic Sea represents the most important wintering area for female long-tailed ducks from Kolguev Island. Important spring and autumn staging areas include the Barents Sea and the White Sea. Climate change will render these habitats more exposed to human impacts in the form of fisheries, marine traffic and oil exploitation in near future. Threats that now operate in the wintering areas may thus spread to the higher latitude staging areas and further increase the pressure on long-tailed ducks. [ABSTRACT FROM AUTHOR]

Background: The wild radishes, Raphanus raphanistrum and R. pugioniformis (Brassicaceae) are native to the East Mediterranean region. However, whereas R. raphanistrum is widely distributed worldwide, the endemic R. pugioniformis is limited to specific habitats. In R. raphanistrum the diaspores of the indehiscent fruits comprise glabrous, light, single-seeded segments, whereas the intact fruits of R. pugioniformis are heavy and covered with spiny backward-pointing trichomes. We aimed to investigate whether the structure of the diaspores was directly associated with long- and short-range dispersal in R. raphanistrum and R. pugioniformis, respectively. We further surveyed within-population spatial distributions, to test the hypothesis that short- and long-range dispersal contribute to a patchy vs. uniform distribution patterns of R. pugioniformis and R. raphanistrum, respectively. Results: The results indicated that dispersal by wind and run-off water was substantially lower for diaspores of R. pugioniformis than for those of R. raphanistrum diaspores. Supporting the hypothesis that backward-pointing trichomes promote adherence to soil particles, the displacement on soil surface of R. pugioniformis fruits depended on their orientation relative to wind direction. Furthermore, trichome removal from fruits of R. pugioniformis significantly reduced wind velocity needed to remove fruits that were placed on soils typical of the species' natural habitats. The spatial-distribution survey results indicated a patchy distribution of R. pugioniformis populations as compared with the more uniform arrangement in the studied populations of R. raphanistrum; consistent with the unidirectional vs. homogeneous wind dispersal of the respective diaspores, with respect to wind direction. In addition, R. pugioniformis population sizes changed less between years than those of R. raphanistrum. Conclusions: Overall, our results indicate that fruit structure is strongly linked to dispersal ability and spatial distribution of the two closely related wild radish species. Whereas R. raphanistrum inhabits homogenous sandy soil habitats, the distribution range of R. pugioniformis includes heterogeneous environments in which growth niches are scarcer. We suggest that the different modes of dispersal have evolved as adaptive traits appropriate to the species' specific habitats. [ABSTRACT FROM AUTHOR]

Background: The 'classical' concept of species diversity was extended in the last decades into other dimensions focusing on the functional and phylogenetic diversity of communities. These measures are often argued to allow a deeper understanding of the mechanisms shaping community assembly along environmental gradients. Because of practical impediments, thus far only very few studies evaluated the performance of these diversity measures on large empirical data sets. Here, data on species-rich riparian moth communities under different flood regimes and from three different rivers has been used to compare the power of various diversity measures to uncover ecological contrasts. Results: Contrary to the expectation, classical metrics of species diversity (Hill numbers N1, N2 and Ninf) and evenness (Buzas-Gibson's E and Pielous's J) turned out to be the most powerful measures in unravelling the two gradients investigated in this study (e.g. flood regime and region). Several measures of functional and phylogenetic diversity tended to depict either only one or none of these contrasts. Rao's Q behaved similarly as species diversity and evenness. NTI and NRI showed a similar pattern among each other but, were different to all the other measures. Functional Divergence also behaved idiosyncratically across the 28 moth communities. The community weighted means of nearly all individual functional traits showed significant ecological patterns, supporting the relevance of the selected traits in shaping assemblage compositions. Conclusions: Species diversity and evenness measures turned out to be the most powerful metrics and clearly reflected both investigated environmental contrasts. This poses the question when it is useful to compile the additional data necessary for the calculation of additional diversity measures, since assembling trait bases and community phylogenies often requires a high work load. Apart from these methodological issues, most of the diversity measures related to communities of terrestrial insects like moths increased in forests that still are subject to flooding dynamics. This emphasizes the high conservation value of riparian forests and the importance of keeping and restoring river dynamics as a means of fostering also terrestrial biodiversity in floodplain areas. [ABSTRACT FROM AUTHOR]

Background: Earthworm communities are generally very sensitive to physico-chemical properties of the soil in different agro-ecosystem i.e. cultivated or non-cultivated which directly or indirectly influence the earthworm survival. The difference in physico-chemical properties of soil at different sites contributed to the formation of population patches for earthworm species. Understanding the physico-chemical properties of soil at a particular site could facilitate the prediction of earthworm species at that site. The objective of the present study was to investigate the diversity, abundance, and distribution of earthworms in cultivated and non-cultivated agroecosystems and their physico-chemical properties affecting the earthworm diversity and abundance. Results: Total 10 species of earthworms i.e. Amynthas alexandri, Amynthas morrisi, Eutyphoeus incommodus, Eutyphoeus waltoni, Metaphire birmanica, Metaphire houlleti, Metaphire posthuma, Octochaetona beatrix, Perionyx excavatus, and Polypheretima elongata, were reported. Out of all the reported species, Metaphire posthuma was found to be the most abundant earthworm species in both cultivated and non-cultivated agroecosystems with the occurrence at 56.81% sites. The Shannon-Wiener index (H), Margalef species richness index (DMg) and Pielou species evenness (E) was ranged from 0 to 0.86, 0 to 0.64 and 0.78 to 1 respectively. The principal component analysis resulted in four principal components i.e. PC1, PC2, PC3 and PC4 which contributing variance (%) of 22.96, 19.37, 14.23 and 10.10 respectively. The principal component analysis also showed that physico-chemical parameters of soil such as EC, pH, TDS, texture, OC, moisture, etc. play a critical role in earthworm distribution. Conclusion: The conventional farming system has a negative effect on the earthworm diversity in the soil while the physico-chemical properties of soil also have a determinant effect on the same. Earthworms abundance in the present study have significant direct relation with soil properties at a particular site and vice versa. The diversity indices also change due to the conventional farming system which directly affects the earthworm abundance. [ABSTRACT FROM AUTHOR]

Background: The climate is the dominant factor that affects the distribution of plants. Cuscuta chinensis is a stem holoparasitic plant without leaves or roots, which develops a haustorium and sucks nutrients from host plants. The potential distribution of the parasitic plant C. chinensis has not been predicted to date. This study used Maxent modeling to predict the potential global distribution of C. chinensis, based on the following six main bioclimatic variables: annual mean temperature, isothermality, temperature seasonality, precipitation seasonality, precipitation of the warmest quarter, and precipitation of the coldest quarter. Results: The optimal annual average temperature and isothermality of C. chinensis ranged from 4 to 37 °C and less than 45, respectively, while the optimal temperature seasonality and precipitation seasonality ranged from 4000 to 25,000 and from 50 to 130, respectively. The optimal precipitation of the warmest season ranged from 300 to 1000 mm and from 2500 to 3500 mm, while that of the coldest season was less than 2000 mm. In Asia, C. chinensis is mainly distributed at latitudes ranging from 20° N to 50° N. During three specific historical periods (last glacial maximum, mid-Holocene, and 1960–1990) the habitats suitable for C. chinensis were concentrated in the central, northern, southern, and eastern parts of China. From the last glacial maximum to the mid-Holocene, the total area with suitability of 0.5–1 increased by 0.0875 million km2; however, from the mid-Holocene to 1960–1990, the total area with suitability of 0.5–1 decreased by 0.0759 million km2. The simulation results of habitat suitability in the two representative concentration pathways (RCP) 2.6 (i.e., the low greenhouse gas emissions pathway) and 8.5 (i.e., the high greenhouse gas emissions pathway) indicate that the habitat suitability of C. chinensis decreased in response to the warming climate. Compared with RCP2.6, areas with averaged suitability and high suitability for survival (RCP8.5) decreased by 0.18 million km2. Conclusion: Suitable habitats of C. chinensis are situated in central, northern, southern, and eastern China. The habitat suitability of C. chinensis decreased in response to the warming climate. These results provide a reference for the management and control of C. chinensis. [ABSTRACT FROM AUTHOR]

Background: Declining resources due to climate change may endanger the persistence of populations by reducing fecundity and thus population fitness via effects on gamete production. The optimal mode of generative reproduction allocates the limited resources to ovule and pollen production in proportions that maximize the number of fertilized ovules in the population. In order to locate this optimum and derive reproduction modes that compensate for declined resources to maintain reproductive success, a model of gamete production, pollen dispersal, and ovule fertilization is developed. Specification of opportunities for compensation is given priority over specification of physiological or evolutionary mechanisms of adaptation. Thus model parameters summarize gametic production resources, resource investment per gamete, resource allocation as proportion of resources invested in ovules, and pollen density as size of the pollen dispersal range and proportion of pollen retained within the range. Retained pollen disperses randomly, and an ovule is fertilized if at least one pollen settles on its surface. The outcome is the expected number of fertilized ovules. Results: Maximization of fertilization success is found to require the investment of more gametic production resources in ovules than in pollen, irrespective of the parameter values. Resource decline can be compensated by adjusting the resource allocation if the maximum expected number of fertilized ovules after the decline is not less than the expected number the population experienced before the decline. Compensation is also possible under some conditions by increasing the pollen density, either by raising a low pollen retention or by shrinking the dispersal range. Conclusion: Fertilization success in populations affected by resource decline may be maintainable by adjustment of the sexual allocation of gametic production resources or by increasing pollen density. The results have implications for insect pollination, sexual allocation bias, management measures, and metapopulation fragmentation. [ABSTRACT FROM AUTHOR]

Background: In species with complex life cycles, size at metamorphosis is a key life-history trait which reflects the complex interactions between costs and benefits of life in the aquatic and terrestrial environments. Whereas the effects of a deteriorating larval habitat (e.g. pond desiccation) on triggering an early metamorphosis have been extensively investigated in amphibians, the consequences of the resulting reduced size at metamorphosis on fitness in the post-metamorphic terrestrial stage remain poorly understood. We tested the hypothesis that a smaller size at metamorphosis negatively affects performance and survival in the ensuing terrestrial stage. Using as model a tropical amphibian (Ceratophrys stolzmanni) showing a large phenotypic plasticity in metamorphosing traits, we evaluated the effects of size at metamorphosis on fitness-related trophic and locomotor performance traits, as well as on growth and survival rates. Results: Our results support the hypothesis that a larger size at metamorphosis is correlated with better survival and performance. The survival rate of large metamorphosing individuals was 95%, compared to 60% for those completing metamorphosis at a small size. Locomotor performance and gape size were positively correlated with body size, larger animals being more mobile and capable to ingest larger prey. However, smaller individuals achieved higher growth rates, thus reducing the size gap. Conclusions: Overall, size at metamorphosis affected profoundly the chances of survival in the short term, but smaller surviving individuals partly compensated their initial disadvantages by increasing growth rates. [ABSTRACT FROM AUTHOR]

Background: Alpine alder vegetation acts upon the nearby grass and dwarf shrub vegetation by the nitrogen supply from the symbiotic bacteria Frankia alni of Alnus viridis. This has been studied in two transects concerning plant distribution, plant diversity, nitrate concentration in soil and photosynthetic performance of specific marker plants. Results: Away from the alder stand, a band of some meters was dominated by Calamagrostis varia which then was followed by alpine dwarf shrub vegetation. Nitrate in the soil showed a concentration decrease away from the alder stand leading to values near the detection limit in the dwarf shrub zone. Within these three zones, plant species were distributed according to their N-index, given in the ecological literature. Three dominant species, Calamagrostis varia, Rhododendron ferrugineum and Vaccinium myrtillus were examined at sites of different N-availability in the horizontal transect for their photosynthetic performance, by measuring the prompt fluorescence, the OJIP named polyphasic rise of chlorophyll-a fluorescence. All three plant species showed signs of stress in the fluorescence rise kinetics at decreased nitrate availability. These are similar to other known stress effects such as faster reduction of the primary acceptor or an electron supply limitation on the donor site of photosystem II. Conclusion: Prompt chlorophyll-a fluorescence data of the examined leaves in a natural vegetation system showed the effects of a decrease in the essential nutrient nitrogen and in a manner parallel to changes in plant diversity. The selected marker plants behaved differently towards decreasing nitrogen concentrations in soil. [ABSTRACT FROM AUTHOR]

Background: Chlorops oryzae is an important pest of rice crops. There have been frequent outbreaks of this pest in recent years and it has become the main rice pest in some regions. To elucidate the molecular mechanism of frequent C. oryzae outbreaks, we estimated the genetic diversity and genetic differentiation of 20 geographical populations based on a dataset of ISSR markers and COI sequences. Results: ISSR data revealed a high level of genetic diversity among the 20 populations as measured by Shannon's information index (I), Nei's gene diversity (H), and the percentage of polymorphic bands (PPB). The mean coefficient of gene differentiation (Gst) was 0.0997, which indicates that only 9.97% genetic variation is between populations. The estimated gene flow (Nm) value was 4.5165, indicating a high level of gene flow and low, or medium, genetic differentiation among some populations. The results of a Mantel test revealed no significant correlation between genetic and geographic distance among populations, which means there is no evidence of significant genetic isolation by distance. An UPGMA (unweighted pair-group method with arithmetic averages) dendrogram based on genetic identity, did not indicate any major geographic structure for the 20 populations examined. mtDNA COI data indicates low nucleotide (0.0007) and haplotype diversity (0.36) in all populations. Fst values suggest that the 20 populations have low, or medium, levels of genetic differentiation. And the topology of a Neighbor-Joining tree suggests that there are no independent groups among the populations examined. Conclusions: Our results suggest that C. oryzae populations have high genetic diversity at the species level. There is evidence of frequent gene flow and low, or medium, levels of genetic differentiation among some populations. There is no significant correlation between genetic and geographic distance among C. oryzae populations, and therefore no significant isolation by distance. All results are consistent with frequent gene exchange between populations, which could increase the genetic diversity, and hence, adaptability of C. oryzae, thereby promoting frequent outbreaks of this pest. Such knowledge may provide a scientific basis for predicting future outbreaks. [ABSTRACT FROM AUTHOR]

Background: While nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. In this study, we used compound-specific isotope analyses of amino acids (CSIA-AA) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petrels, from a sub-Antarctic seabird community. Results: CSIA-AA allowed comparing trophic positions of seabirds with temperate and polar distributions. Gentoo and Magellanic penguins had the highest trophic positions during the breeding season (3.7 and 3.9), but decreased these (2.9 and 3.3) during the feed-up for moult. Intra-specific differences were also detected in Thin-billed prions, where carbon isotope values clearly separated individuals with polar and temperate distributions, both in the breeding and interbreeding periods. Thin-billed prions that foraged in polar waters had lower trophic positions (3.2) than conspecifics foraging in temperate waters (3.8). We further investigated historical changes by comparing museum samples with samples collected recently. Our pilot study suggests that Rockhopper penguins, Magellanic penguins and Thin-billed prions with temperate non-breeding distributions had retained their trophic levels over a 90–100 year period, while Gentoo penguins and Thin-billed prions with polar non-breeding distributions had decreased trophic levels compared to historical samples. In contrast, Wilson's storm-petrels had slightly increased trophic levels compared to samples taken in 1924–1930. Conclusions: We applied compound-specific stable isotope analyses across a range of contexts, from intra-specific comparisons between stages of the breeding cycle to inter-specific seabird community analysis that would not have been possible using bulk stable isotope analyses alone due to differences in isotopic baselines. [ABSTRACT FROM AUTHOR]

Background: The most severe bacterial disease of honeybees is American foulbrood (AFB). The epidemiology of AFB is driven by the extreme spore resilience, the difficulty of bees to remove these spores, and the considerable incidence of undetected spore-producing colonies. The honeybee collective defence mechanisms and their feedback on colony development, which involves a division of labour at multiple levels of colony organization, are difficult to model. To better predict disease outbreaks we need to understand the feedback between colony development and disease progression within the colony. We therefore developed Bayesian models with data from forty AFB-diseased colonies monitored over an entire foraging season to (i) investigate the relationship between spore production and symptoms, (ii) disentangle the feedback loops between AFB epidemiology and natural colony development, and (iii) discuss whether larger insect societies promote or limit within-colony disease transmission. Results: Rather than identifying a fixed spore count threshold for clinical symptoms, we estimated the probabilities around the relationship between spore counts and symptoms, taking into account modulators such as brood amount/number of bees and time post infection. We identified a decrease over time in the bees-to-brood ratio related to disease development, which should ultimately induce colony collapse. Lastly, two contrasting theories predict that larger colonies could promote either higher (classical epidemiological SIR-model) or lower (increasing spatial nest segregation and more effective pathogen removal) disease prevalence. Conclusions: AFB followed the predictions of the SIR-model, partly because disease prevalence and brood removal are decoupled, with worker bees acting more as disease vectors, infecting new brood, than as agents of social immunity, by removing infected brood. We therefore established a direct link between disease prevalence and social group size for a eusocial insect. We furthermore provide a probabilistic description of the relationship between AFB spore counts and symptoms, and how disease development and colony strength over a season modulate this relationship. These results help to better understand disease development within honeybee colonies, provide important estimates for further epidemiological modelling, and gained important insights into the optimal sampling strategy for practical beekeeping and honeybee research. [ABSTRACT FROM AUTHOR]

Background: Natural habitats are typically structured, imposing constraints on inhabiting populations and their interactions. Which conditions are important for coexistence of diverse communities, and how cooperative interaction stabilizes in such populations, have been important ecological and evolutionary questions. Results: We investigate a minimal ecological framework of microbial population dynamics that exhibits crucial features to show coexistence: Populations repeatedly undergo cycles of separation into compartmentalized habitats and mixing with new resources. The characteristic time-scale is longer than that typical of individual growth. Using analytic approximations, averaging techniques and phase-plane methods of dynamical systems, we provide a framework for analyzing various types of microbial interactions. Population composition and population size are both dynamic variables of the model; they are found to be decoupled both in terms of time-scale and parameter dependence. We present specific results for two examples of cooperative interaction by public goods: collective antibiotics resistance, and enhanced iron-availability by pyoverdine. We find stable coexistence to be a likely outcome. Conclusions: The two simple features of a long mixing time-scale and spatial compartmentalization are enough to enable coexisting strains. In particular, costly social traits are often stabilized in such an environment—and thus cooperation established. [ABSTRACT FROM AUTHOR]

Background: A long-term experiment at two trial sites in Kenya has been on-going since 2007 to assess the effect of organic and conventional farming systems on productivity, profitability and sustainability. During these trials the presence of significant numbers of termites (Isoptera) was observed. Termites are major soil macrofauna and within literature they are either depict as 'pests' or as important indicator for environmental sustainability. The extent by which termites may be managed to avoid crop damage, but improve sustainability of farming systems is worthwhile to understand. Therefore, a study on termites was added to the long-term experiments in Kenya. The objectives of the study were to quantify the effect of organic (Org) and conventional (Conv) farming systems at two input levels (low and high) on the abundance, incidence, diversity and foraging activities of termites. Results: The results showed higher termite abundance, incidence, activity and diversity in Org-High compared to Conv-High, Conv-Low and Org-Low. However, the termite presence in each system was also dependent on soil depth, trial site and cropping season. During the experiment, nine different termite genera were identified, that belong to three subfamilies: (i) Macrotermitinae (genera: Allodontotermes, Ancistrotermes, Macrotermes, Microtermes, Odontotermes and Pseudocanthotermes), (ii) Termitinae (Amitermes and Cubitermes) and (iii) Nasutitiermitinae (Trinervitermes). Conclusions: We hypothesize that the presence of termites within the different farming systems might be influenced by the types of input applied, the soil moisture content and the occurrence of natural enemies. Our findings further demonstrate that the organic high input system attracts termites, which are an important, and often beneficial, component of soil fauna. This further increases the potential of such systems in enhancing sustainable agricultural production in Kenya. [ABSTRACT FROM AUTHOR]

Background: Glucocorticoids mediate responses to perceived stressors, thereby restoring homeostasis. However, prolonged glucocorticoid elevation may cause homeostatic overload. Using extensive field investigations of banded mongoose (Mungos mungo) groups in northern Botswana, we assessed the influence of reproduction, predation risk, and food limitation on apparent homeostatic overload (n=13 groups, 1542 samples from 268 animals). We experimentally manipulated reproduction and regulated food supply in captive mongooses, and compared their glucocorticoid responses to those obtained from free-living groups. Results: At the population level, variation in glucocorticoid levels in free-living mongooses was explained by food limitation: fecal organic matter, recent rainfall, and access to concentrated anthropogenic food resources. Soil macrofauna density and reproductive events explained less and predation risk very little variation in glucocorticoid levels. Reproduction and its associated challenges alone (under regulated feeding conditions) increased glucocorticoid levels 19-fold in a captive group. Among free-living groups, glucocorticoid elevation was seasonal (occurring in late dry season or early wet season when natural food resources were less available), but the timing of peak glucocorticoid production was moderated by access to anthropogenic resources (groups with fewer anthropogenic food sources had peaks earlier in dry seasons). Peak months represented 12- and 16-fold increases in glucocorticoids relative to nadir months with some animals exhibiting 100-fold increases. Relative to the captive group nadir, some free-living groups exhibited 60-fold increases in peak glucocorticoid levels with some animals exhibiting up to 800-fold increases. Most of these animals exhibited 1- to 10-fold increases relative to the captive animal peak. Conclusions: Banded mongooses exhibit seasonal chronic glucocorticoid elevation, associated primarily with food limitation and secondarily with reproduction. Magnitude and duration of this elevation suggests that this may be maladaptive for some animals, with possible fitness consequences. In late dry season, this population may face a convergence of stressors (food limitation, agonistic encounters at concentrated food resources, evictions, estrus, mate competition, parturition, and predation pressure on pups), which may induce homeostatic overload. [ABSTRACT FROM AUTHOR]

Background: Optimal foraging theory explains how animals make foraging decisions based on the availability, nutritional content, and handling times of different food types. Generalists solve this problem by consuming a variety of food types, and alter their diets with relative ease. Specialists eat few food types, and may starve if those food types are not available. We integrated stable isotope analyses with previously-published stomach contents and environmental data to investigate how the foraging ecologies of three sympatric freshwater turtle species vary across four wetlands that differ in turbidity and primary producer abundance. Results: We found that the generalist Emydura macquarii consumes a varied diet (but mostly filamentous green algae) when primary producers are available and water is clear, but switches to a more carnivorous diet when the water is turbid and primary producers are scarce, following the predictions of optimal foraging theory. In contrast, two more-specialized carnivorous species, Chelodina expansa and Chelodina longicollis, do not differ in diet across wetlands, and interspecific competition may increase where E. macquarii is carnivorous. When forced to be more carnivorous, E. macquarii exhibits higher rates of empty stomachs, and female turtles have reduced body condition, but neither Chelodina species are affected. Conclusions: Our results provide support for optimal foraging theory, but also show that the ability to change diet does not protect the generalist from experiencing lower foraging success when its preferred food is rare, with direct consequences for their energy budgets. Our results have conservation implications because wetlands in the Murray–Darling river system are increasingly turbid and have low macrophyte abundance, and all three species are declining. [ABSTRACT FROM AUTHOR]

Background: Breeding programs and research activities where artificial buzz-pollinations are required to have primarily relied upon using tuning forks, and bumble bees. However, these methods can be expensive, unreliable, and inefficient. To find an alternative, we tested the efficiency of pollen collection using electric toothbrushes and compared it with tuning forks at three vibration frequencies—low, medium, and high and two extraction times at 3 s and 16 s- from two buzz—pollinated species (Solanum lycopersicum and Solanum elaeagnifolium). Results: Our results show that species, and extraction time significantly influenced pollen extraction, while there were no significant differences for the different vibration frequencies and more importantly, the use of a toothbrush over tuning fork. More pollen was extracted from S. elaeagnifolium when compared to S. lycopersicum, and at longer buzzing time regardless of the instrument used. Conclusions: Our results suggest that electric toothbrushes can be a viable and inexpensive alternative to tuning forks, and regardless of the instrument used and buzzing frequency, length of buzzing time is also critical in pollen extraction. [ABSTRACT FROM AUTHOR]

Background: Spartina alterniflora is an invasive plant on the coast of China that replaces native vegetation and has a serious negative impact on local ecosystems. Monitoring the spatial distribution of S. alterniflora and its changes over time can reveal its expansion mechanism, which is crucial for the management of coastal ecosystems. The purpose of this study was to map the distribution of S. alterniflora in Zhejiang Province from 1985 to 2015 using a time series of Landsat TM/OLI images and analyze the temporal and spatial patterns of expansion of this species. Results: After analyzing the distribution of coastal vegetation, the vegetation index was calculated based on Landsat images for 4 years (1985, 1995, 2005 and 2015). According to a threshold determined based on expert knowledge, the distribution of S. alterniflora in Zhejiang Province was extracted, and the temporal and spatial changes in the distribution of S. alterniflora were analyzed. The classification accuracy was 90.3%. S. alterniflora has expanded rapidly in recent decades after being introduced into southern Zhejiang. Between 1985 and 2015, S. alterniflora increased its area of distribution by 10,000 hm2, and it replaced native vegetation to become the most abundant halophyte in tidal flats. Overall, S. alterniflora expanded from south to north over the decades of the study, and the fastest expansion rate was 463.64 hm2/year, which occurred between 1995 and 2005. S. alterniflora was widely distributed in the tidal flats of bays and estuaries and expanded outward as sediment accumulated. Conclusions: This study reveals the changes over time in S. alterniflora cover in Zhejiang and can contribute to the control and management of this invasive plant. [ABSTRACT FROM AUTHOR]

Background: This paper provides a short introduction to the topic of citizen science (CS) identifying the shift from the knowledge deficit model to more inclusive, participatory science. It acknowledges the benefits of new technology and the opportunities it brings for mass participation and data manipulation. It focuses on the increase in interest in CS in recent years and draws on experience gained from the Open Air Laboratories (OPAL) programme launched in England in 2007. Methods: The drivers and objectives for OPAL are presented together with background information on the partnership, methods and scales. The approaches used by researchers ranged from direct public participation in mass data collection through field surveys to research with minimal public engagement. The supporting services focused on education, particularly to support participants new to science, a media strategy and data services. Results: Examples from OPAL are used to illustrate the different approaches to the design and delivery of CS that have emerged over recent years and the breadth of opportunities for public participation the current landscape provides. Qualitative and quantitative data from OPAL are used as evidence of the impact of CS. Conclusion: While OPAL was conceived ahead of the more recent formalisation of approaches to the design, delivery and analysis of CS projects and their impact, it nevertheless provides a range of examples against which to assess the various benefits and challenges emerging in this fast developing field. [ABSTRACT FROM AUTHOR]

Background: Animal colour patterns offer good model systems for studies of biodiversity and evolution of local adaptations. An increasingly popular approach to study the role of selection for camouflage for evolutionary trajectories of animal colour patterns is to present images of prey on paper or computer screens to human 'predators'. Yet, few attempts have been made to confirm that rates of detection by humans can predict patterns of selection and evolutionary modifications of prey colour patterns in nature. In this study, we first analyzed encounters between human 'predators' and images of natural black, grey and striped colour morphs of the polymorphic Tetrix subulata pygmy grasshoppers presented on background images of unburnt, intermediate or completely burnt natural habitats. Next, we compared detection rates with estimates of capture probabilities and survival of free-ranging grasshoppers, and with estimates of relative morph frequencies in natural populations. Results: The proportion of grasshoppers that were detected and time to detection depended on both the colour pattern of the prey and on the type of visual background. Grasshoppers were detected more often and faster on unburnt backgrounds than on 50% and 100% burnt backgrounds. Striped prey were detected less often than grey or black prey on unburnt backgrounds; grey prey were detected more often than black or striped prey on 50% burnt backgrounds; and black prey were detected less often than grey prey on 100% burnt backgrounds. Rates of detection mirrored previously reported rates of capture by humans of free-ranging grasshoppers, as well as morph specific survival in the wild. Rates of detection were also correlated with frequencies of striped, black and grey morphs in samples of T. subulata from natural populations that occupied the three habitat types used for the detection experiment. Conclusions: Our findings demonstrate that crypsis is background-dependent, and implicate visual predation as an important driver of evolutionary modifications of colour polymorphism in pygmy grasshoppers. Our study provides the clearest evidence to date that using humans as 'predators' in detection experiments may provide reliable information on the protective values of prey colour patterns and of natural selection and microevolution of camouflage in the wild. [ABSTRACT FROM AUTHOR]

Background: The availability of preferred habitats determines the spatial and temporal distribution of herbivores in savanna ecosystems. Understanding habitat preference of a targeted wildlife species is crucial for developing effective conservation strategies. Habitat preference of large grazers in connection to grass height and post-fire effect has been debated for the last century. Here, we examined the effects of season, grass height and burning on the habitat preference on Swayne's hartebeest (Alcelaphus buselaphus swaynei) in Maze National Park. Data for seasonal habitat selection were collected using both direct observation along established transect lines and pellet counting using permanently established plots. Every month, we measured grass height commonly preferred by Swayne's hartebeest in grassland habitat. Starting from the first week of burning, we recorded the abundance of Swayne's hartebeest in both burned and unburned grassland patches. Results: From detected pellets, 94.3% were recorded in the grassland habitat indicating that other habitat types are less used despite their extensive cover > 50% of the Park. During wet and early dry seasons, Swayne's hartebeest exclusively preferred grassland habitat. We found that 85.2% (n = 1079) and 85.3% (n = 593) of individuals observed in areas with a grass height below 30 cm during wet and early-dry seasons, respectively; while 70.9% (n = 2288) preferred grass height below 30 cm during the dry season. The density of Swayne's hartebeest in burned grassland area was higher than unburned grassland areas up to 150 days since burning. However, in unburned grassland areas, the density was initially low but showed increasing trend for consecutive days, reaching similar density with burned areas after 150 days since burning. Conclusion: Swayne's hartebeest exclusively preferred grassland habitat, particularly during wet and early-dry seasons, shortest available grass height in all seasons and were attracted to burned grassland areas. Our results suggested that fire played an important role in maintaining habitat quality in grassland, and that management should continue using controlled burning as a tool for the conservation of Swayne's hartebeest. However, we remain cautious of our findings given the paucity of information regarding other confounding factors and the absence of long-term data on fire disturbance. [ABSTRACT FROM AUTHOR]

Background: Coexistence is enabled by ecological differentiation of the co-occurring species. One possible mechanism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difficult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling hermit crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the availability of gastropod shells. In the present study, we used two co-occurring terrestrial hermit crab species, Coenobita rugosus and C. perlatus, to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Results: Field sampling of eleven separated hermit crab populations showed that the two co-occurring hermit crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of different intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphology with narrow aperture. Conclusion: The two terrestrial hermit crab species occur in the same habitat but have evolved different preferences towards distinct subsets of the limiting shell resource. Resource partitioning might therefore be the main driver of their ecological differentiation, which ultimately allowed these co-occurring species to coexist in their environment. As the preferred shell morphology of C. rugosus maximizes reproductive output at the expense of protection, while the preferred shell morphology of C. perlatus maximizes protection against predation at the expense of reproductive output, shell resource partitioning might reflect different strategies to respond to the same set of selective pressures occurring in beach habitats. This work offers empirical support for the competitive exclusion principle-hypothesis and demonstrates that hermit crabs are an ideal model organism to investigate resource partitioning in natural populations. [ABSTRACT FROM AUTHOR]

Background: Wild boars (Sus scrofa L.) are globally widely distributed, and their populations have increased in Europe during recent decades. Encounters between humans and wild boars are rare because of the predominantly nocturnal lifestyle of the latter, and wild boar management by hunting is a challenging task. Animal activity patterns are important for understanding the behaviour of a species. However, knowledge of detailed temporal patterns and an understanding of the drivers of wild boar activity at a fine temporal scale are lacking. Of special relevance for human–wild boar interactions (e.g., encounters, conflicts, and management) is the question of whether nocturnal activity depends on anthropogenic factors and, particularly, how local hunting regimes may affect activity patterns. We used GPS telemetry and acceleration measurements to shed light on this part of wild boar behaviour, observing 34 animals in Central Europe. Animals were tracked along a gradient of hunting pressure from hunting-free areas to areas with low or high hunting pressure. Fitted generalised additive models allowed predicting the probability of active behaviour under differing disturbance regimes precisely to day of year and time of day. Results: The wild boars were predominantly nocturnal, with peak activity at approximately midnight. However, the data showed increased activity during daylight for wild boars that used no-hunting zones or reduced-hunting zones. Large areas with low disturbance levels promoted activity during daylight more than smaller areas with an intermediate disturbance regime. High air temperatures and locations within forests reduced the probability of active behaviour, whereas proximity to tracks used for forestry or agriculture was accompanied by a higher probability of activity. Conclusions: We conclude that wild boars flexibly adjust their activity to their local environmental conditions, considering disturbances at the scale of long-term home ranges as well as actual small-scale landscape quality. Entire wild boar home ranges should be covered in the delineation of reserves intending to stimulate activity during daylight. [ABSTRACT FROM AUTHOR]

Background: Accurate network models of species interaction could be used to predict population dynamics and be applied to manage real world ecosystems. Most relevant models are nonlinear, however, and data available from real world ecosystems are too noisy and sparsely sampled for common inference approaches. Here we improved the inference of generalized Lotka–Volterra (gLV) ecological networks by using a new optimization algorithm to constrain parameter signs with prior knowledge and a perturbation-based ensemble method. Results: We applied the new inference to long-term species abundance data from the freshwater fish community in the Illinois River, United States. We constructed an ensemble of 668 gLV models that explained 79% of the data on average. The models indicated (at a 70% level of confidence) a strong positive interaction from emerald shiner (Notropis atherinoides) to channel catfish (Ictalurus punctatus), which we could validate using data from a nearby observation site, and predicted that the relative abundances of most fish species will continue to fluctuate temporally and concordantly in the near future. The network shows that the invasive silver carp (Hypophthalmichthys molitrix) has much stronger impacts on native predators than on prey, supporting the notion that the invader perturbs the native food chain by replacing the diets of predators. Conclusions: Ensemble approaches constrained by prior knowledge can improve inference and produce networks from noisy and sparsely sampled time series data to fill knowledge gaps on real world ecosystems. Such network models could aid efforts to conserve ecosystems such as the Illinois River, which is threatened by the invasion of the silver carp. [ABSTRACT FROM AUTHOR]

Background: In fragmented landscapes, natural and anthropogenic disturbances coupled with successional processes result in the destruction and creation of habitat patches. Disturbances are expected to reduce metapopulation occupancy for species associated with stable habitats, but they may benefit species adapted to transitory habitats by maintaining a dynamic mosaic of successional stages. However, while early-successional species may be favoured by very frequent disturbances resetting successional dynamics, metapopulation occupancy may be highest at intermediate disturbance levels for species with mid-successional habitat preferences, though this may be conditional on species traits and patch network characteristics. Here we test this 'intermediate disturbance hypothesis' applied to metapopulations (MIDH), using stochastic patch occupancy simulation modelling to assess when does intermediate disturbance favour metapopulation occupancy. We focused on 54 virtual species varying in their habitat preferences, dispersal abilities and local extinction and colonization rates. Long-term metapopulation dynamics was estimated in landscapes with different habitat amounts and patch turnover rates (i.e. disturbance frequency). Results: Equilibrium metapopulation occupancy by late-successional species strongly declined with increasing disturbance frequency, while occupancy by early-successional species increased with disturbance frequency at low disturbance levels and tended to level-off thereafter. Occupancy by mid-successional species tended to increase along with disturbance frequency at low disturbance levels and declining thereafter. Irrespective of habitat preferences, occupancy increased with the amount of habitat, and with species dispersal ability and colonisation efficiency. Conclusions: Our study suggests that MIDH is verified only for species associated with mid-successional habitats. These species may be particularly sensitive to land use changes causing either increases or decreases in disturbance frequency. This may be the case, for instance, of species associated with traditional agricultural and pastoral mosaic landscapes, where many species disappear either through intensification or abandonment processes that change disturbance frequency. [ABSTRACT FROM AUTHOR]

Background: Multiple logistic regression is precluded from many practical applications in ecology that aim to predict the geographic distributions of species because it requires absence data, which are rarely available or are unreliable. In order to use multiple logistic regression, many studies have simulated "pseudo-absences" through a number of strategies, but it is unknown how the choice of strategy influences models and their geographic predictions of species. In this paper we evaluate the effect of several prevailing pseudo-absence strategies on the predictions of the geographic distribution of a virtual species whose "true" distribution and relationship to three environmental predictors was predefined. We evaluated the effect of using a) real absences b) pseudo-absences selected randomly from the background and c) two-step approaches: pseudo-absences selected from low suitability areas predicted by either Ecological Niche Factor Analysis: (ENFA) or BIOCLIM. We compared how the choice of pseudo-absence strategy affected model fit, predictive power, and information-theoretic model selection results. Results: Models built with true absences had the best predictive power, best discriminatory power, and the "true" model (the one that contained the correct predictors) was supported by the data according to AIC, as expected. Models based on random pseudo-absences had among the lowest fit, but yielded the second highest AUC value (0.97), and the "true" model was also supported by the data. Models based on two-step approaches had intermediate fit, the lowest predictive power, and the "true" model was not supported by the data. Conclusion: If ecologists wish to build parsimonious GLM models that will allow them to make robust predictions, a reasonable approach is to use a large number of randomly selected pseudoabsences, and perform model selection based on an information theoretic approach. However, the resulting models can be expected to have limited fit. [ABSTRACT FROM AUTHOR]

Background: Pleistocene glaciations have had an important impact on the species distribution and community composition of the North American biota. Species survived these glacial cycles south of the ice sheets and/or in other refugia, such as Beringia. In this study, we assessed, using mitochondrial DNA from three Diptera species, whether flies currently found in Beringian grasslands (1) survived glaciation as disjunct populations in Beringia and in the southern refugium; (2) dispersed northward postglacially from the southern refugium; or (3) arose by a combination of the two. Samples were collected in grasslands in western Canada: Prairies in Alberta and Manitoba; the Peace River region (Alberta); and the southern Yukon Territory. We sequenced two gene regions (658 bp of cytochrome c oxidase subunit I, 510 bp of cytochrome b) from three species of higher Diptera: one with a continuous distribution across grassland regions, and two with disjunct populations between the regions. We used a Bayesian approach to determine population groupings without a priori assumptions and performed analysis of molecular variance (AMOVA) and exact tests of population differentiation (ETPD) to examine their validity. Molecular dating was used to establish divergence times. Results: Two geographically structured populations were found for all species: a southern Prairie and Peace River population, and a Yukon population. Although AMOVA did not show significant differentiation between populations, ETPD did. Divergence time between Yukon and southern populations predated the Holocene for two species; the species with an ambiguous divergence time had high haplotype diversity, which could suggest survival in a Beringian refugium. Conclusions: Populations of Diptera in Yukon grasslands could have persisted in steppe habitats in Beringia through Pleistocene glaciations. Current populations in the region appear to be a mix of Beringian relict populations and, to a lesser extent, postglacial dispersal northward from southern prairie grasslands. [ABSTRACT FROM AUTHOR]