Journal of Animal Ecology最新文献

Global trends in marine turtle nesting numbers vary by region, influenced by environmental or anthropogenic factors. Our study investigates the potential role of past temperature fluctuations on these trends, particularly whether warmer beaches are linked to increased nesting due to higher female production (since sea turtles have temperature-dependent sex determination). We selected the loggerhead turtle (Caretta caretta) due to its wide distribution, strong philopatry and vulnerability to environmental changes. We compiled nest counts per year on 35 globally significant rookeries, analysing trends at regional and individual beach levels. We compiled air (CHELSA) and land surface (MODIS) temperature data sets spanning the last four decades (1979-2023) for each location. To analyse temporal trends in nest counts and temperatures, we used generalised additive models and Mann-Kendall trend tests. Additionally, we correlated nest counts with lagged air temperature variables. We found significant warming at 33 nesting locations, 23 of which also showed significant increases in nest counts. Our results suggest that rising temperatures may be boosting nest numbers in regions of the Caribbean, Atlantic Ocean and Mediterranean (sites in Cayman, Mexico, Brazil, Cyprus and Turkey). Furthermore, while some regions temporarily benefit, continued warming could precipitate long-term population declines. This regional variability helps predict species responses to climate change, with the general global increase in nest counts already indicating short-term warming effects. Nesting count trends might reflect a combination of natural ecological phenomena, conservation efforts, and warming effects. Long-term studies are needed to assess global trends in the sex ratio of hatchlings and the extent to which feminisation is driving nest numbers.

Research Highlight: Edwards, O. M., Zhai, L., Reichert, M. S., Shaughnessy, C. A., Ozment, L., & Zhang, B. (2024). Physiological and morphological traits affect contemporary range expansion and implications for species distribution modelling in an amphibian species. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.14212. Range expansion can have profound ecological and evolutionary consequences that feedback on the expansion process itself. With global climate change causing widespread species range shifts to higher latitudes and altitudes, it is essential that we better understand these dynamics during native range expansion in the wild. In a recent study on poleward-spreading treefrogs (Hyla cinerea), Edwards et al. (2024) measured how morphological and physiological traits differed between populations from the recently expanded and historic range. They found that range-edge frogs had increased cold tolerance and longer legs associated with better dispersal, which could strongly affect the rate and geographic limits of expansion. Edwards et al. then show how species distribution models fit separately to the historic and expanded range more accurately predict habitat suitability near the historic range boundary. This paper provides a timely and compelling example of rapid differentiation in dispersal and niche traits during native range expansion, and explores ways in which we can model species range shifts while accounting for this phenotypic variation in space and time.

Research Highlight: Iannarilli, F., Gerber, B. D., Erb, J., & Fieberg, J. R. (2024). A ‘how-to’ guide for estimating animal diel activity using hierarchical models. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.14213. Diel activity patterns are ubiquitous in living organisms and have received considerable research attention with advances in the collection of time-stamped data and the recognition that organisms may respond to global change via behaviour timing. Iannarilli et al. (2024) provide a roadmap for analysing diel activity patterns with hierarchical models, specifically trigonometric generalized linear mixed-effect models and cyclic cubic spline generalized additive models. These methods are improvements over kernel density estimators, which for nearly two decades have been the status quo for analysing activity patterns. Kernel density estimators have several drawbacks; most notably, data are typically aggregated (e.g. across locations) to achieve sufficient sample sizes, and covariates cannot be incorporated to quantify the influence of environmental variables on activity timing. Iannarilli et al. (2024) also provide a comprehensive tutorial which demonstrates how to format data, fit models, and interpret model predictions. We believe that hierarchical models will become indispensable tools for activity-timing research and envision the development of many extensions to the approaches described by Iannarilli et al. (2024).

Animal colour patterns are often accompanied by specific, synergistic behaviours to most effectively defend prey against visual predators. Given the inherent context-dependence of colour perception, understanding how these colour-behaviour synergies function in a species' natural environment is crucial. For example, refuge-building species create a unique visual environment where most (or all) of the body is obscured unless closely inspected. How these built environments affect the perception of defensive colour patterns by predators is not well understood. Using artificial caterpillars that resemble a refuge-building species with conspicuous markings (Papilio troilus; Lepidoptera: Papilionidae), I tested the hypothesis that leaf rolls amplify the antipredator effect of this species' eyespots. I compared wild avian predation rates on 659 artificial swallowtail-like caterpillars from four treatment groups: eyespotted and non-eyespotted, and presented in leaf rolls or on open leaves of live host plants. In support of my hypothesis, eyespots only reduced predation for larvae in leaf rolls. On open leaves, eyespots had no antipredator effect. I also found that leaf rolls reduced predation in general for both eyespotted and non-eyespotted prey. These results highlight the importance of considering relevant behaviours in studies of animal coloration whenever possible, including behaviours that influence colour perception indirectly (e.g. through habitat use or modification).

Research Highlights: Schausberger, P., & Nguyen, T. H. (2024). Early social isolation disrupts adult personality expression in group-living mites. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.14169. Personality traits in animals have been of great interest in the last decades. The number of studies demonstrating the existence of personality in a wide range of taxa is growing rapidly. Although the effect of early experience on later average values of behavioural traits is well documented, very few articles demonstrate the effects of those factors on personality expression itself. One factor in particular received very little, if not no, attention: social isolation. Although social isolation is known to have major impacts on later animal behaviour, it is still unknown whether it may favour or inhibit personality expression. In a recent study, Schausberger and Nguyen (2024) demonstrated that early-life social isolation had strong effects on adults of the predatory mite Phytoseiulus persimilis. They show for the first time that early social isolation decreased the expression of personality in the activity of adults when tested in a social context. Interestingly, they observed the opposite effect when the same mites were tested alone: previously isolated mites were highly repeatable but group-reared mites were not. Finally, they also show an indirect effect of early social isolation through mating: mating with a male who experienced social isolation increased the behavioural repeatability of females. This study not only reinforces the established understanding of personality but also paves the way for future research in the field.