Biology subjects

Dulude-de Broin, F.

Publications and source records attributed to Dulude-de Broin, F..

5 recordsLinked to original sources

bioRxiv2025

Predicting space use patterns of a territorial top predator: from individual movement decisions to Arctic fox space use

O_LIPredicting animal space use could greatly improve our understanding and forecasting of ecological processes. Despite growing interest, the development of predictive space use models amenable to the integration of spatial processes into ecological frameworks have yet to reach their full potential. C_LIO_LIUsing high-resolution tracking data collected at 4-minute intervals from 26 Arctic foxes over five years, we developed a predictive space use model based on a step-selection approach. We assessed fine-scale habitat selection in relation to prey distribution, landscape features, and ecological constraints such as central place foraging and territoriality. We then used these results to build an agent-based model simulating fox space use and evaluated its ability to reproduce observed space use patterns. C_LIO_LIStep-selection analyses confirmed that fox movements were driven by habitat type, goose nest density, distance to den, and avoidance of distance to the home range boundary. Agent-based simulations closely matched empirical tracking data and accurately forecasted fox space use, even for individuals excluded from model parameterization. C_LIO_LIBy developing a predictive model of predator space-use, our study provides a foundation for incorporating additional components of the predation sequence and contributes to more spatially informed approaches in predator-prey ecology. C_LI

ecology↗

bioRxiv2025

Timing matters: phenological constraints and predation shape Arctic community structure

Top-down and bottom-up controls of animal populations are key elements of niche and coexistence theories, but there is still little empirical evidence on how these forces determine species distribution and community assemblies. In Arctic ecosystems, spring snowmelt sets the timing and duration of the snow-free period, thereby controlling food availability, while predation often imposes additional constraints on prey species. The relative importance of these abiotic and biotic filters on distribution is also susceptible to vary with body size. Using 10 years of high-resolution data on all major members of an Arctic vertebrate community and their shared predator, we tested how snowmelt timing interacts with predation to shape species occurrence and community structure. Species occurrence declined with later snowmelt dates, with larger-bodied species being particularly constrained by short snow-free periods. Predation further modulated species occurrence, with responses varying according to body mass. Our findings highlight the combined influence of the phenology of food availability and predation as important filters shaping local community structure. Building on species contrasted responses, we propose a conceptual framework for how phenological constraints and predation jointly shape community assembly in highly seasonal environments.

ecology↗

bioRxiv2024

Integrating predator energetic balance, risk-taking behavior and microhabitat in functional response: Untangling indirect interactions in a multispecies vertebrate community

1O_LIPredator-prey interactions in natural communities are complex, with predators often exploiting multiple prey types and generating indirect interactions among them. Ecological theory has traditionally modeled these interactions using functional responses models which are based on foraging rates, not energy transfers. This approach overlooks how the energy acquisition rate of a predator can alter its behavior and, in turn, the strength of species interactions. C_LIO_LIHere, we integrate predator energetics into a functional response model to represent trade-offs predators face when foraging on prey that vary in risk and abundance across heterogeneous landscapes. We compared model predictions to 20 years of prey species density and reproductive success data. The mechanistic model was parameterized for an Arctic tundra vertebrate community, where the Arctic fox feeds on cyclic lemmings and eggs of sandpipers (non-risky prey) and gulls (risky prey that often nest in partial refuge like islands). In this system, predator-mediated interactions generate apparent mutualism between lemmings and birds, but its strength varies between species, and the mechanisms underlying this interaction remain unclear. C_LIO_LIWe found that fox energetic balance was highly related to lemming density, with a threshold of 89 lemmings per km2 required for a positive energetic balance. Model-predicted gull nest acquisition rates were lowest on islands when the energetic balance of foxes was positive, and highest for nests on the shore when foxes were in deficit. The model that incorporated predator risk-taking behavior and energetic balance produced variation in gull hatching success that most closely matched empirical observations. C_LIO_LIWe documented for the first time that a shift in predator energetic balance, triggering changes in attack and capture probabilities on a risky prey, can be a key mechanism underlying the apparent mutualism between lemmings and gulls. In contrast, for non-risky prey, the indirect effect can be essentially driven by changes in predator movement. These findings highlight how prey characteristics can lead to different mechanisms behind similar indirect interactions. C_LIO_LITaken together, our results indicate that mechanistic models integrating species traits, landscape features, and energy-dependent behavioral adjustments can improve our ability to quantify interaction strengths in natural communities. C_LI

ecology↗

bioRxiv2024

Territoriality and resource availability modulate the effect of conspecific encounters on the foraging behaviours of a mammalian predator

The probability of encountering conspecifics shapes multiple dimensions of animal behaviour. For example, territorial individuals increase vigilance, scent marking and alarm calling when approaching home range boundaries. Whether territorial predators modify their foraging behaviours with respect to the probability of encountering neighbouring territory owners is poorly understood. However, this could strongly influence the landscape of predation risk and therefore modulate predator-prey interactions. We studied the movements and behaviours of 23 resident Arctic foxes occupying neighbouring home ranges during two years of contrasting resource availability (abundant resources in 2019, scarce resources in 2022) on Bylot Island, Nunavut, Canada. First, based on simultaneous GPS tracking of individuals, we established which individuals used a territory (an exclusive area) by estimating the spatial distribution of the probability of encountering a neighbour within their home range. Second, using GPS and accelerometry data, we evaluated if the probability of encountering a neighbour influenced the spatial distribution of foraging behaviours, and whether this relationship differed between territorial and non-territorial individuals. When resources were abundant, only breeding individuals excluded other foxes from a part of their home range and were thus territorial. When resources were rare, none of the foxes reproduced and all but one were territorial. Non-territorial individuals in 2019 were less likely to cache prey in areas with a high probability of encounter, possibly reducing the risk of cache pilfering. We found no effect of the probability of encounter on the behaviours of the non-territorial individual in 2022. The probability to cache prey of territorial individuals however did not depend on the probability of encountering a neighbour, suggesting they have no benefit of modulating the distribution of their caches according to potential encounters in a partly exclusive area. Our results thus suggest that Arctic foxes use different tactics to secure resources based on their degree of territoriality and the availability of resources. We highlight how the presence of resident, but non-territorial predators, whose home ranges overlap those of their territorial neighbours, may influence the distribution of predation risk by creating zones where predator density is high, potentially influencing predator-prey interactions.

ecology↗

bioRxiv2020

The predator activity landscape predicts the anti-predator behavior and distribution of prey in a tundra community

Predation shapes communities through consumptive and non-consumptive effects, where in the latter prey respond to perceived predation risk through risk management strategies occurring at different spatial and temporal scales. The landscape of fear concept is useful to better understand how predation risk affects prey behavioral decisions and distribution, and more generally the spatial dimension of predator-prey relationships. We assessed the effects of the predation risk landscape in a terrestrial Arctic community, where arctic fox is the main predator of ground-nesting bird species. Using high frequency GPS data, we developed a predator activity landscape resulting from fox space use patterns, and validated with an artificial prey experiment that it generated a predation risk landscape. We then investigated the effects of the fox activity landscape on multiple prey, by assessing the anti-predator behavior of a primary prey (snow goose) and the nest distribution of several incidental prey. Areas highly used by foxes were associated with a stronger level of nest defense by snow geese. We further found a lower probability of occurrence of incidental prey nests in areas highly used by foxes, but only for species nesting in habitats easily accessible to foxes. Species nesting in refuges consisting of micro-habitats limiting fox accessibility, like islets, did not respond to the fox activity landscape. Consistent with the scale of the fox activity landscape, this result reflected the capacity of refuges to allow bird nesting without regard to predation risk in the surrounding area. We demonstrated the value of using predator space use patterns to infer spatial variation in predation risk and better understand its effects on prey in landscape of fear studies. We also exposed the diversity of prey risk management strategies, hence refining our understanding of the mechanisms driving species distribution and community structure.

ecology↗