Journal of Animal Ecology最新文献

The timing of breeding is an important aspect of any species' realised niche, reflecting adaptations to synchronise with food supplies, dilute predation, avoid competition and exploit seasonal fluctuations in resources. Breeding phenology is typically studied either through long-term monitoring of focal populations (limiting the strength of inferences about species-wide traits and trends) or, when conducted at a landscape level, using remotely visible traits (restricting most studies to plants). For the first time, this study demonstrates landscape-scale measurement of vertebrate breeding phenology using a network of 77 time-lapse cameras to monitor three sympatric penguin species across 37 colonies in the Antarctic Peninsula and Sub-Antarctic islands. Camera temperature loggers showed penguin colony locations are warming up four times faster (0.3°C/year) than the continental average (0.07°C/year), already the second fastest-warming area in the world. We analysed the start of the breeding season of Adélie, Chinstrap and Gentoo penguins at a sub-continental scale between 2012 and 2022. The phenology of all three species advanced at record rates (10.2 ± 2, 10.4 ± 1.5 and 13 ± 4 days/decade, respectively). Different demographic trends as well as intra- and inter-species differences in response to environmental change suggest niche-based response differences between species. Phenological advances are causing niche separation to reduce. In this context, the Gentoo penguins' generalist and resident nature seems better suited to compete for space and resources than krill-specialist Chinstraps and ice-specialist Adélies. Synthesis: A decade of observation of the three pygoscelid penguins shows they are advancing their settlement phenology at record speeds in relation to climate change across the Antarctic Peninsula. These changes are species-dependent, reflecting different vulnerabilities and opportunities depending on their niche and life-history traits. In the long term, the trend towards earlier settlement risks increasing inter-species competition, causing trophic and temporal mismatch, and reshaping community assemblages.

Research Highlight: Han P, Yang Y, Kajanus MH, Lu W, Chen Q, Ding P, Si X. (2025). Community composition coupled with habitat fragmentation drives acoustic divergence in bird assemblages. Journal of Animal Ecology doi: 10.1111/1365-2656.70185. Animals that communicate acoustically have to deal with the problem of getting their message through environments often crowded by acoustic signals from other individuals (from the same and different species). This poses the problem that the signal of interest may be masked by these other sounds, lowering the probability that it will be detected/discriminated by targeted receivers. The acoustic niche hypothesis (ANH; Krause 1993) predicts that acoustic signals will occupy different acoustic niches (e.g. different frequencies, Hz) to lower competition for the acoustic space. Han et al. (2025) put this idea to the test. While various studies have tested the acoustic niche hypothesis in relation to biotic factors (e.g. species richness and abundance), Han et al. (2025) went one step further by also considering habitat fragmentation and isolation. To do so, they recorded the songs of 51 bird species in 12 islands differing in size (as a measure of habitat fragmentation) and distance to nearest island and mainland (as a measure of isolation). Han et al. (2025) also took into account body mass and evolutionary history. As expected, they found that biotic factors (body mass and species richness) and phylogenetic relationships were associated with the degree of competition and acoustic partitioning. Interestingly, the authors also found that island size and isolation played an important role (acoustic partitioning increased in more isolated islands and in smaller islands). These results confirm the ANH and provide evidence that habitat fragmentation and isolation can also play a role influencing acoustic partitioning in birds.

Quantifying how energy moves through ecosystems has been a central objective for ecologists since the early development of the field because it helps to understand how and why food webs are structured the way they are. Yet, for as long as it has been of intellectual interest, it has also been a logistical challenge. Ramirez and colleagues employ cutting-edge stable isotope techniques to show that, in contrast to expectations, human impacts do not strongly alter energy pathways in coral reef ecosystems.

Although difficult to carry out, long-term studies are essential for understanding the trajectories of biological systems and organisms in response to environmental change. Despite becoming more common, studies providing interannual data on insect populations remain rare, although they have confirmed widespread insect declines. In the case of dung beetles-a key group among decomposers-no existing studies provide continuous annual data over a period exceeding 20 years. This study describes changes in species richness, abundance, biomass and assemblage composition of dung beetle assemblages across 16 sites in a semi-arid region of central Spain, sampled on 9 occasions over 26 years. The results reveal a marked regional decline in these metrics, evident in two-thirds of the sites, three-quarters of the recorded species and the main functional groups. This decline coincided with the disappearance of traditional sheep grazing in the region and involved a 50% reduction in species richness and a 65% decrease in both abundance and biomass. Despite interannual fluctuations, a slight rebound in the populations of some species was observed approximately 17 years after the decline in trophic resources. The presence of rabbit dung and the distance from urban centres emerged as key factors that may help to mitigate biodiversity loss in these assemblages following the abandonment of traditional livestock grazing. It is suggested that, after rural depopulation, wild mammals-particularly rabbits-may act as a reservoir, facilitating the recovery of dung beetle populations and preventing local extinction.

Research Highlight: Ben Mocha, Y., Woith, M., Scemama de Gialluly, S., Bruscagnin, L., Kestel, N., Markman, S., Drobniak, S. M., Baglione, V., Boersma, J., Cousseau, L., Covas, R., Braga de Miranda, G. H., Dey, C. J., Doutrelant, C., Gula, R., Heinsohn, R., Keynan, O., Kingma, S. A., Leitão, A. V., … Griesser, M. (2025). An integrative, peer-reviewed open-source cooperative-breeding database (Co-BreeD). Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.70154. The Cooperative-Breeding Database (Co-BreeD) is an open, peer-reviewed resource that collects data on cooperative breeding across birds and mammals, including humans. As such, it serves as a valuable resource for studies on sociality and cooperation. Currently, Co-BreeD provides population-level data on nearly 40,000 breeding events from 316 species and is growing. The database allows for cooperative breeding to be treated as a continuous rather than binary trait, and at finer spatial and temporal scales, enabling detailed exploration of the ecological and evolutionary drivers of cooperation. This novel approach revealed that alloparental care, and hence cooperative breeding, is likely more widespread than previously recognised. The importance of curated, high-quality, and accessible data across ecology and evolution is becoming evident; Co-BreeD has great potential to contribute to such collaborative, reproducible, and robust research.

The ability of consumers to adjust their diet in response to resource shifts is a key mechanism allowing the persistence of populations and underlying species' adaptive capacity. Yet on coral reefs, one of the marine habitats most vulnerable to global change, the extent to which species alter their diet and the consequences of dietary shifts for consumer performance and ecosystem functioning remain poorly understood. Here, we tested how dietary versatility can mediate the effects of habitat degradation on two invertivorous reef fishes-Chaetodon capistratus, a browser, and Hypoplectrus puella, an active predator-and whether diet shifts relate to variation in body condition and growth. We integrated DNA-based gut content analyses (metabarcoding), otolith analysis, body condition and field surveys to link diet profiles to growth and relative body condition across reefs differing in coral cover. Metabarcoding revealed significant dietary variation in both species across reefs with different levels of coral cover. However, the response was more pronounced in the browser, whose diet was anthozoan-dominated on healthier reefs, whereas it was annelid-dominated on degraded reefs. We found significantly more variable body condition on degraded reefs in the browser, while the body condition of the active predator decreased in larger individuals on degraded reefs. Our results suggest that while dietary versatility serves as a mechanism to cope with degraded environments, the degree to which dietary shifts can buffer against the effects of habitat degradation varies between species. Overall, the variation in trophic niche across sites suggests that food webs and energy flow differ at relatively small scales between healthy and degraded reefs.

Habitat imprinting is the phenomenon where exposure to cues in the natal habitat increases the probability of choosing a habitat with similar cues later in life. It is considered a key behavioural mechanism that decreases the costs associated with habitat selection. The similarity of breeding to natal habitats can be especially beneficial when choosing the first breeding site and when the choice has long-term consequences due to high site fidelity. Habitat imprinting in breeding habitat selection has rarely been documented in wild animals living in unmanipulated environments and is challenging to study in long-lived species with delayed maturity. We used a combination of genetic and visual identification to identify 354 white-tailed eagles Haliaeetus albicilla hatched between 1991 and 2015 that were subsequently documented breeding between 2001 and 2023 along the Baltic Sea coast or in the inland environments. We examined (a) the similarity of natal and breeding habitats and (b) the effects of natal dispersal distance on this similarity. Furthermore, (c) we were interested in breeding habitat selection and tested whether eagles showed a preference for natal-like habitats among suitable territories that were at the time still unoccupied. We found that breeding habitats were similar to natal habitats, independent of natal dispersal distance. Eagles were also more likely to choose a natal-like breeding site among available alternative sites. These results indicate that habitat imprinting is a possible driving mechanism in the habitat selection of long-lived animals with delayed maturity and has important implications for conservation actions such as eagle reintroduction programmes.

In the face of global coral decline, coral reefs in the Gulf of Aqaba (GOA), northern Red Sea are considered a coral reef refuge from global warming and acidification, with echinoid herbivory playing a fundamental role in maintaining their balance. Like many echinoderms, echinoids are known for their 'boom-and-bust' population fluctuations. However, as population fluctuations are influenced by multiple, complex and non-linear processes that operate at various temporal scales, short-term studies may fail to capture the true trajectories of population trends. We explored echinoid population dynamics in the GOA, spanning 15 years (2007-2022), complemented by historical data dating back to the 90s and 70s. We show that while some species oscillated around a steady mean, others collapsed by up to 98%. Consequently, the once most common herbivores on these reefs currently account for only a fraction of their population size from half a century ago. Increased anthropogenic stress attributed to the accelerated regional urbanization, rather than the direct effect of a single environmental variable, is suggested as a key facilitating driver of the observed declines. This study reveals ongoing, alarming declines of key echinoid species, calling for rapid, species-aware management. We highlight the necessity to transition from year-long to decades-long monitoring to facilitate the detection of ongoing, long-term trends.

Social interactions among conspecifics can have significant fitness implications, but how social behaviours develop in wild animals remains poorly understood. Here, we examine the intrinsic drivers of a social behaviour, communal winter roosting, in red kites Milvus milvus. In this species, communal roosting is a facultative behaviour, and the mechanisms underlying its emergence at the individual and population levels are unclear. Through longitudinal GPS tracking of 635 bird-winters from 216 red kites, we derived multi-year roosting histories to investigate (i) which individual characteristics associate with the decision to join communal roosts, (ii) how these patterns change across life stages and (iii) whether roost composition reflects assortative associations among breeding pairs or kin. Based on 33,930 nights across six consecutive winters on the breeding grounds, we identified red kites from our tagged sample joining communal roosts on average 38% of the time. Males occurred more at communal roosts than females, but in both sexes this probability drastically decreased with age and additionally decreased once they started breeding. These ontogenetic changes in communal roosting behaviour were driven by behavioural plasticity at the individual level rather than selective mortality. Red kites displayed assortative behaviour both in communal and non-communal roosting contexts. Breeding pairs showed the strongest affiliation, roosting more often together than expected by chance in non-communal roosting sites, when in proximity to their breeding territory. In contrast, sibling and parent-offspring dyads were rare, and roosting less frequently together than expected by chance within communal roosts. Overall, our results show that the structure of communal roosts in the red kite is shaped by the age, sex and social relationships of individuals. The influence of these factors may stem from trade-offs across various life history stages, driven by changes in the net benefits associated with foraging, territory and mate prospecting, as well as territory maintenance throughout an individual's life.