Jodie Martin

Freelance Researcher

This study aimed to (1) identify the scale of environmental drivers of seasonal movements on the migration – residency behavior continuum in a large herbivore species and to (2) test the hypothesis that the same environmental drivers and spatio-temporal scaling should influence spatial processes in both migrants (long distance migration) and reside...

Context Routine movements of large herbivores, often considered as ecosystem engineers, impact key ecological processes. Functional landscape connectivity for such species influences the spatial distribution of associated ecological services and disservices. Objectives We studied how spatio-temporal variation in the risk-resource trade-off, genera...

Prey mortality depends on the likelihood of encountering a predator and of being killed following such an encounter. While the proactive responses of large herbivores to the risk of predation have been well documented, the reactive responses of prey following encounters have been less well studied and restricted mostly to northern temperate ecosyst...

Moon phase affects nocturnal activity patterns in mammals. Among ungulates, a number of studies have found animals to be more active over full moon nights. This may be because increased luminosity provides increased opportunity to forage and/or increased ability to detect predators; known as the visual acuity hypothesis. Here, we use GPS-derived mo...

Niche separation among species with similar resource requirements can be expressed at various spatiotemporal scales, from the resource components selected at feeding sites to habitat and home range occupation and ultimately geographic distribution ranges. African large herbivores present a challenge to niche theory because multiple species commonly...

An intermediate spatiotemporal scale of food procurement by large herbivores is evident within annual or seasonal home ranges. It takes the form of settlement periods spanning several days or weeks during which foraging activity is confined to spatially discrete foraging arenas, separated by roaming interludes. Extended by areas occupied for other...

Movement is a key mean for mobile species to cope with heterogeneous environments. While in herbivorous mammals large-scale migration has been widely investigated, fine-scale movement responses to local variations in resources and predation risk remain much less studied, especially in savannah environments. We developed a novel approach based on co...

The domestic cat has been introduced on several sub-Antarctic islands such as the Kerguelen archipelago (48 28 50 S, 68 28 70 35E), causing a worrying impact on the viability of some seabird populations. A better understanding of the biology of this introduced predator is needed to help design appropriate management actions. To investigate the effe...

Habitat selection studies generally assume that animals select habitat and food resources at multiple scales to maximise their fitness. However, animals sometimes prefer habitats of apparently low quality, especially when considering the costs associated with spatially heterogeneous human disturbance. We used spatial variation in human disturbance,...

Movement is fundamental to individual and population dynamics, as it allows individuals to meet their basic requirements. Although movement patterns reflect interactions between internal and external factors, only few studies have examined the effects of these factors on movement simultaneously, and they generally focused on particular biological c...

1. Identification of suitable habitats for small, endangered populations is important to preserve key areas for potential augmentation. However, replicated spatial data from a sufficient number of individuals are often unavailable for such populations, leading to unreliable habitat models. This is the case for the endangered Pyrenean brown bear Urs...

No-take reserves are sometimes implemented for sustainable population harvesting because they offer opportunities for animals to spatially avoid harvesters, whereas harvesters can benefit in return from the reserve spillover. Here, we used the framework of predator-prey spatial games to understand how protected areas shape spatial interactions betw...

In human-dominated landscapes, species with large spatial requirements, such as large carnivores, have to deal with human infrastructure and activities within their home ranges. This is the case for the brown bear (Ursus arctos L., 1758) in Scandinavia, which is colonizing more human-dominated landscapes, leading inevitably to an overlap between th...

Understanding the relationships between organisms and their habitat is a central question in ecology. The study of habitat selection often refers to the static description of the pattern resulting from the selection process. However the very nature of this habitat selection process is dynamic, as it relies on individual movements, which are affecte...

The aim of this study is to empirically illustrate the importance of taking movement constraints into account when testing for habitat selection with telemetry data. Global Positioning System relocations of two Scandinavian brown bears were used to compare the results of two different tests of habitat selection by the bears within their home range....

Brown bears (Ursus arctos) are threatened by habitat loss, habitat fragmentation by infrastructure and human settlements, and have been hunted to local extinction in large areas of their former range. We analyzed the habitat use during the non denning period of 106 radio-collared bears in an expanding bear population in Sweden in relation to resort...