Biology subjects

Vanderlocht, C.

Publications and source records attributed to Vanderlocht, C..

3 recordsLinked to original sources

bioRxiv2026

Multidimensional isotopic niches inform coexistence mechanisms in an Alpine ungulate community

O_LIUnderstanding functional community structure and the niche-based mechanisms that enable coexistence among sympatric species is essential for explaining how biodiversity is maintained in natural systems, and for anticipating how ecological communities will respond to ongoing environmental change. Stable isotope analysis provides a process-oriented perspective on resource use by integrating information across time and space, thereby allowing reconstruction of realised isotopic niches that reflect multiple dimensions of ecological differentiation. C_LIO_LIWe applied this framework to a community of ungulates in the Central-Eastern Italian Alps, including red deer (Cervus elaphus), roe deer (Capreolus capreolus), and Alpine chamois (Rupicapra rupicapra). Using stable isotope ratios in summer-grown hair segments ({delta}13C, {delta}15N, {delta}34S, {delta}18O, {delta}2H), we quantified species-specific n-dimensional niche hypervolumes within a Bayesian framework and estimated niche regions, overlap probabilities, univariate differentiation and multivariate structure. C_LIO_LIDespite broad dietary overlap typically observed among these ungulates, we found clear isotopic niche segregation, with mean pairwise overlap consistently remaining below 40%. Three dimensions emerged as primary drivers of differentiation: water sourcing ({delta}18O), diet quality ({delta}15N), and habitat openness ({delta}13C). Specifically, chamois appeared to derive more water from plants in their diet rather than from drinking, and to consume a higher-quality diet compared to Cervids. Red deer relied more heavily on forested habitats for resource use compared to roe deer and chamois, and additional isotopic differences between red deer and roe deer may stem from fine-scale abiotic conditions like microclimate and topography. We found no isotopic evidence for differential niche breadth among the three ungulate species. C_LIO_LITogether, these patterns highlight functional differentiation across multiple ecological axes, offering mechanistic insight into how these ungulates segregate realised niche space despite substantial potential for resource overlap. This multi-element isotope perspective underscores the value of integrative, process-based approaches for understanding current coexistence as well as improving predictions of how mammal communities may reorganise under accelerating environmental change. C_LI

ecology↗

bioRxiv2025

Living with urban fear: vervet monkey response to an evolutionarily new predator

Humans have facilitated contacts between prey and predator species that have originally not co-evolved, reshuffling the prey-predator arms race. How do prey cope with an evolutionarily new predation risk? We tracked three vervet monkey troops in a South-African semi-urban habitat for 14 months to study their response to domestic dogs. We show that monkeys responded to dogs with a two-pronged behaviour: they emitted alarm calls, and became more vigilant and displayed aggressive behaviours towards the dogs. While their movement highlighted risk-prone behaviour, they appeared to have mapped and planned for risk, as they reacted more strongly when risk was unexpected. The response intensity was further modulated by risk labels typically encountered in their natural environment, but not by labels uniquely associated with dogs. This highlights that vervet monkeys responded with ingrained behaviour to this evolutionarily new threat, anticipating risk based on long-term spatial memory, but failed to integrate evolutionarily new information. TeaserVervet monkeys fear domestic dogs but fail to adjust their antipredator response by discriminating evolutionarily new risk labels.

animal behavior and cognition↗

bioRxiv2024

Movement responses to lethal risk: an integrative analysis of proactive and reactive antipredator behaviours in a large herbivore

Prey species can display antipredation movement behaviours to reduce predation risk including proactive responses to chronic or predictable risk, and reactive responses to acute or unpredictable risk. Thus, at any given time, prey movement choice may reflect the trade-off between proaction and reaction. In previous studies, proaction and reaction have generally been considered separately, which neglects their simultaneous influence on animal decisions. In this study, we analysed how proaction and reaction interact to shape the movements of GPS-collared red deer (Cervus elaphus), in response to human hunting of conspecifics. Our results show that red deer proactively selected canopy cover where and when risk was predictably high. However, when they were unable to avoid risk, canopy cover was no longer selected, but only modulated a reactive response along a freeze-to-escape continuum. This reaction was even more evident when the environment was unfamiliar, underlining the importance of memory in such reaction patterns. Therefore, to our knowledge, for the first time, we describe how proaction and reaction fuse in an antipredation sequence of interconnected movement decisions in a large herbivore, and we lay the foundations for further investigations into the evolutionary origins of similarities and differences between proactive and reactive behaviours.

ecology↗