Journal of Animal Ecology最新文献

Research Highlight: Dri, G. F., Bogdziewicz, M., Hunter, M., Witham, J., & Mortelliti, A. (2025). Coupled effects of forest growth and climate change on small mammal abundance and body weight: Results of a 39-year field study. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70114. Biodiversity is declining due to global environmental change, yet it remains challenging to assess how specific drivers, such as climate change, affect the dynamics and trends of individual species. While many studies correlate climate variables with species abundance or occurrence, few explicitly link environmental drivers to demographic processes to uncover the mechanisms behind population trends. Such insight requires long-term data capable of revealing slow-moving, nonlinear trends and disentangling natural variability from directional change. In a 39-year study, Dri et al. (2025) demonstrate the power of sustained observation and mechanistic approaches by linking climate warming and forest maturation to increased acorn production, which enhanced body condition and survival in white-footed mice, ultimately driving population increases. Their findings underscore the importance of long-term data for identifying meaningful ecological trends and tracing the causal pathways by which biodiversity changes. Effective conservation under global change depends on two key shifts: greater investment in long-term biodiversity monitoring and broader adoption of frameworks that explicitly connect environmental drivers to demographic responses. Together, these approaches provide the foundation for adaptive, evidence-based conservation strategies in a rapidly changing world.

Research Highlight: Myers, J. H., & Cory, J. S. (2025). Long-term population dynamics of western tent caterpillars: History, trends and causes of cycles. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70104. For centuries, population cycles have intrigued ecologists and posed challenges for resource managers. These dramatic fluctuations are influenced by strong interactions with natural enemies and/or the climate, yet these external drivers alone are typically insufficient to explain the observed cycles. Cyclic changes in life-history traits (e.g. fecundity) often play a significant role, though the mechanisms underlying these regular phenotypic shifts remain largely undetermined. Here Myers and Cory (2025) convincingly demonstrate the key role of plastic changes in fecundity in driving the 8–11-year population cycles of the western tent caterpillar Malacosoma californicum pluviale. These cycles are partially driven by lethal infections from a specialized baculovirus Malacosoma pluviale nucleopolyhedrovirus. Although tent caterpillars evolve increased resistance to the virus following peak infection periods, this resistance does not incur a fecundity cost, suggesting that eco-evolutionary feedback does not regulate this cycle. Instead, sublethal viral infections induce plastic reductions in fecundity. Declines in food quantity and quality following peak defoliation periods likely further contribute to these plastic changes. While climate variation does influence population growth, future climate change is unlikely to disrupt these cycles. Taken together, this long-term research underscores the importance of phenotypic plasticity in shaping dramatic herbivore population cycles. Future research on eco-evolutionary dynamics should consider, more even-handedly, alternative mechanisms by which the environment can feedback to cause phenotypic change.

Exposure to stressors and associated hormones during development can significantly affect offspring phenotype, including social and philopatric behaviour, but these effects can be mediated by the postnatal social environment ('social buffering'). While the effects of social buffering are well established for complex social behaviours-such as parental provisioning, grooming or cooperative care-the role of social buffering for simpler social interactions-such as parental tolerance of offspring-remains less understood. Here we used the facultatively social viviparous lizard, Liopholis whitii, to test the following: (i) the effects of elevated maternal glucocorticoid levels during gestation on offspring mass, growth, dispersal and social interactions after birth; and (ii) whether these effects are mediated by postnatal mother-offspring association. We conducted a factorial experiment in which pregnant lizards were given thrice-weekly doses of a glucocorticoid hormone (corticosterone) or a control during gestation. Their offspring were then raised either alone or with their mother for 3 weeks. We subsequently released mothers and offspring in large semi-natural enclosures and quantified offspring mass and social/exploratory behaviour. There were persistent negative effects of prenatal glucocorticoid exposure on offspring growth. We also observed lasting effects of prenatal glucocorticoid exposure on social behaviour: offspring from glucocorticoid-treated mothers had stronger social associations with other individuals, including with their mother and siblings, compared to offspring from control mothers. Association with their mother early in life did not mediate the effects of prenatal glucocorticoid exposure on offspring phenotype. These effects demonstrate that maternal stress can be an important mediator of variation in social behaviour in lizards, even overriding the influence of the social environment in the early postnatal period. This has potential implications for understanding how social groups form and are maintained.