Effect of behavioral marginality on survival of an alpine ungulate

Abstract

Inter‐individual variability in behavior has been studied extensively for a wide range of species. However, few researchers have considered marginality, defined as the degree to which a choice made by an individual is located at the margins of the distribution of all possible choices available to a particular population. We explored the influence of marginal behaviors on the probability of survival of woodland caribou (Rangifer tarandus caribou). We used GPS collars to record the movement and fate of 43 caribou and distributed their habitat use behavior along two axes of a multidimensional scaling. We used Cox proportional‐hazards models to evaluate whether marginality had an effect on mortality risk. We found that individuals that exhibited marginal behavior had higher mortality risk than more conformist individuals. Caribou is a social species; thus, sharing a common habitat use strategy is likely an adaptation for minimizing the risk of predation. Our findings provide an empirical link between behavior and survival, contributing to our understanding of the decline of Rangifer across much of its Canadian distribution.

A Caribou Decline Foreshadowed by Inuit in the Central Canadian Arctic: A Retrospective Analysis

“…data). It is important to manage land use across the entire range because caribou herds that persist with constricted distributions have been linked to higher cortisol levels (Ewacha et al, 2017), restricted genetic flow (Thompson et al, 2019), reduced resilience to predation (Lesmerises et al, 2019), higher susceptibility to rain-on-snow events (Macias-Fauria and Post, 2018), and a higher conservation risk (Lucas et al, 2019). The participatory mapping highlights the potential advantages and limitations of TK in conservation settings and reinforces the importance of ensuring multi-community representation to obtain a comprehensive understanding of a migratory species with a large range.…”

Trophic niche partitioning between two prey and their incidental predators revealed various threats for an endangered species

“…These changes have supported increases in moose density from 1.0 to 8.0 moose/10 km 2 between 1992 and 2011 (Dorais, 2015). This increase was accompanied by an increase in bear and coyote densities (Frenette et al, 2020) that has exacerbated the predation pressure on caribou calves (Crête & Desrosiers, 1995) and adults (Lesmerises et al, 2019) via an apparent competition phenomenon ( sensu Holt, 1977). This habitat‐mediated apparent competition is responsible for low calf recruitment rates (~8 calves per 100 females, Morin & Lesmerises, 2020) and low adult survival rates (77% for females and 56% for males in 2014 and 2015; Frenette et al, 2020).…”

Untangling Effects of Human Disturbance and Natural Factors on Mortality Risk of Migratory Caribou

“…Marginal individuals can face a higher risk of mortality because they are not as good at avoiding or defending themselves against predators when isolated from most of the population. These caribou also might have bolder personalities, which may place them in riskier situations (Lesmerises et al, 2019). Alternatively, habitats strongly selected by the population are presumably high-quality habitats that may contribute to maintain or improve body condition, and ultimately survival.…”

“…We first considered a habitat use hypothesis, where mortality risk of caribou is mostly affected by the proportion of time spent in highly selected habitats (H1; Figure 1A). We expected that caribou spending less time in habitats that are strongly selected at the population level would face a higher risk of mortality because of the potentially lower quality of these habitats or to the marginality of their behavior (e.g., bolder personalities), which could increase predation risk (Lesmerises et al, 2019). Alternatively, the use of highly selected habitats could be a "non-ideal" behavior, being inefficient at reducing the mortality risk associated with one or more factors.…”