Evidence for nonconsumptive effects from a large predator in an ungulate prey?

Predators can indirectly affect prey survival and reproduction by evoking costly antipredator responses. Such nonconsumptive effects may be as strong or stronger than consumptive predator effects. However, evidence for this in large terrestrial vertebrate systems is equivocal and few studies quantify the actual fitness costs of nonconsumptive effects. Here, we investigated whether nonconsumptive effects elicited by Eurasian lynx (Lynx lynx), a large terrestrial predator, reduced survival in an ungulate prey, the European roe deer (Capreolus capreolus). To reveal the behavioral processes underlying nonconsumptive effects, we distinguished between proactive risk avoidance of areas with high lynx encounter probability, and reactive risk avoidance in response to actual lynx encounters and analyzed these responses using step selection functions. We also quantified the consequences of these behaviors for deer survival. Deer reacted differently at day and at night, but avoided high-risk areas proactively during the day and at night in the summer. During a predator encounter, deer increased avoidance of high-risk areas at night but not during the day. Thus, roe deer exhibited a behavioral response race that involved temporally and spatially varying tradeoffs with environmental constraints. We found evidence that nonconsumptive effects of lynx predation risk reduced deer survival and that survival was more sensitive to variation in nonconsumptive effects of lynx than to variation in human proximity. Our findings highlight that nonconsumptive effects may depend on the spatiotemporal distribution of risks and the environmental context, and we discuss how human factors contribute to predator–prey dynamics in human dominated landscapes

Comparing survey methods to assess the conservation value of a community-managed protected area in western Tanzania

The ability of low‐status protected areas under community management to achieve a conservation objective is frequently questioned, particularly in developing countries. The lack of sound, scientific‐based biodiversity monitoring frequently undermines attempts to evaluate the extent to which these areas are contributing to biodiversity conservation. Based on data collected between 2008 and 2010 in a Forest Reserve under community management in western Tanzania, our study tested fives methods: camera trapping, walking line transects, vehicle transects, opportunistic encounters and indirect signs, to find the most appropriate for future monitoring. Method comparisons confirmed a higher performance of camera trapping compared to other methods for the ability to detect species. However, our results identified the need of a better survey design to ensure a sound monitoring in the future. Besides method comparisons, our study provides the first fine‐scale data on mammal communities in such a low‐status protected area. Combined methods allow the identification of 49 species of medium and large mammals, a surprisingly high diversity for such area. These findings outline the potential conservation value of this type of protected area and call for better biodiversity monitoring throughout complexes of protected areas of different statuses and management regimes

PredRisk_KillData

This table contains the predations risk values (based on a lynx resource selection function) of the 199 lynx killed roe deer used in Gehr et al. 2018 (Behavioral Ecology). As time of kill was unknown the predation risk values were calculated for midnight. For information on the raw data or for R-code used to calculate the predation risk please contact the data owner

Evidence for nonconsumptive effects from a large predator in an ungulate prey?

Predators not only affect prey survival directly through predation, but they can also affect prey survival and reproduction indirectly by evoking costly antipredator responses. Here, we present evidence that a large terrestrial mammalian predator elicits strong antipredator behavioral responses in an ungulate prey, which indirectly affect prey survival. This is one of few large terrestrial mammal studies that provide evidence for the survival costs of antipredator responses in their prey

Data from: Evidence for nonconsumptive effects from a large predator in an ungulate prey?

Pedators can indirectly affect prey survival and reproduction by evoking costly anti-predator responses. Such non-consumptive effects may be as strong or stronger than consumptive predator effects. However, evidence for this in large terrestrial vertebrate systems is equivocal and few studies quantify the actual fitness costs of non-consumptive effects. Here we investigated whether non-consumptive effects elicited by Eurasian lynx (Lynx lynx), a large terrestrial predator, reduced survival in an ungulate prey, the European roe deer (Capreolus capreolus). To reveal the behavioral processes underlying non-consumptive effects, we distinguished between proactive risk avoidance of areas with high lynx encounter probability, and reactive risk avoidance in response to actual lynx encounters and analyzed these responses using step selection functions. We also quantified the consequences of these behaviors for deer survival. Deer reacted differently at day and at night, but avoided high-risk areas proactively during the day and at night in the summer. During a predator encounter, deer increased avoidance of high-risk areas at night but not during the day. Thus, roe deer exhibited a behavioral response race that involved temporally and spatially varying tradeoffs with environmental constraints. We found evidence that non-consumptive effects of lynx predation risk reduced deer survival and that survival was more sensitive to variation in non-consumptive effects of lynx than to variation in human proximity. Our findings highlight that non-consumptive effects may depend on the spatiotemporal distribution of risks and the environmental context, and we discuss how human factors contribute to predator-prey dynamics in human dominated landscapes

Data from: Hunting-mediated predator facilitation and superadditive mortality in a European ungulate

Predator-prey theory predicts that in the presence of multiple types of predators using a common prey, predator facilitation may result as a consequence of contrasting prey defense mechanisms, where reducing the risk from one predator increases the risk from the other. While predator facilitation is well established in natural predator-prey systems, little attention has been paid to situations where human hunters compete with natural predators for the same prey. Here, we investigate hunting-mediated predator facilitation in a hunter-predator-prey system. We found that hunter avoidance by roe deer (Capreolus capreolus) exposed them to increase predation risk by Eurasian lynx (Lynx lynx). Lynx responded by increasing their activity and predation on deer, providing evidence that superadditive hunting mortality may be occurring through predator facilitation. Our results reveal a new pathway through which human hunters, in their role as top predators, may affect species interactions at lower trophic levels and thus drive ecosystem processes

Data from: A landscape of coexistence for a large predator in a human dominated landscape

Human related mortality is a major threat for large carnivores all over the world and there is increasing evidence that large predators respond to human related risks in a similar way as prey respond to predation risk. This insight recently led to the conceptual development of a landscape of coexistence that can be used to identify areas which can sustain large predator populations in human dominated landscapes. In this study we applied the landscape of coexistence concept to a large predator in Europe. We investigated to what extent Eurasian lynx Lynx lynx habitat selection is affected by human disturbance in a human dominated landscape. More specifically, we were interested in the existence of a tradeoff between the availability of roe deer, one of their main prey and avoidance of human disturbance and how this affects the spatio-temporal space use patterns of lynx. We found that lynx face a tradeoff between high prey availability and avoidance of human disturbance and that they respond to this by using areas of high prey availability (but also high human disturbance) during the night when human activity is low. Furthermore our analysis showed that lynx increase their travelling speed and remain more in cover when they are close to areas of high human disturbance. Despite clear behavioral adjustments in response to human presence, prey availability still proved to be the most important predictor of lynx occurrence at small spatial scale, whereas human disturbance was considerably less important. The results of our study demonstrate how spatio-temporal adaptations in habitat selection enable large carnivores to persist in human dominated landscapes and demonstrate the usefulness of the concept of a landscape of coexistence to develop adaptive management plans for endangered populations of large carnivores

deer_data

This table contains the GPS locations of roe deer associated with habitat variables and temporal variables that were used to build a habitat model (RSF) for roe deer. The table is divided into used (actual) deer locations and random locations (loc_id=NA) in a ratio of 1:10 (column "use"). The table also includes an animal id. Swisstopo in the column headers refers to the source of the environmental variables. Cover swisstopo is a dummy variable for open/cover. Slope_sq and altitude_sq are the squared slope and altitude variables. Aspect swisstopoS is the southern exposition. Hum_indx is a composite of road_dist and house density. The 8 temporal variables are time harmonics of a Fourier transform for time of day (tsin, tcos, tsin2, tcos2; period of 24) and day of year(ytsin, ytcos, ytsin2, ytcos2; period of 365) All continuous variables in this table are mean centered and standardized to a SD=1. For information on the raw data or for R-code used to run the models please contact the data owner