Natal habitat preference induction in large mammals-Like mother, like child?

Abstract

Habitat selection has received considerable attention from ecologists during the last decades, yet the underlying forces shaping individual differences in habitat selection are poorly documented. Some of these differences could be explained by the early experience of individuals in their natal habitat. By selecting habitat attributes like those encountered early in life, individuals could improve resource acquisition, survival, and ultimately fitness. This behavior, known as natal habitat preference induction (NHPI), could be particularly common in large mammals, because offspring generally stay with their mother for an extended period. We used three complementary approaches to assess NHPI in a marked population of woodland caribou (Rangifer tarandus caribou): (a) population-based resource selection functions (RSFs), (b) individual-based RSFs, and (c) behavioral repeatability analyses. All approaches compared the behavior of calves in their natal range to their behavior as independent subadults during the snow-covered (Dec-Apr) and snow-free (May-Nov) seasons. Using RSFs, we found that the magnitude of habitat selection between calf and subadult stages differed for most covariates, yet the signs of statistically significant effects (selection vs. avoidance) were generally the same. We also found that some habitat selection tactics were highly repeatable across life stages. Notably, caribou responses to habitat disturbances were highly repeatable year-round, meaning that different individuals reacted differently, but consistently, to disturbances. This study highlights the potential role of natal habitat preference induction in shaping individual differences in habitat selection in large mammals and provides valuable knowledge for the management and conservation of a threatened species.

Keywords: Rangifer tarandus caribou; natal experience; natal habitat preference induction; repeatability; resource selection functions; woodland caribou.

Figure 1

A mother with her calf, in the boreal woodland caribou (Rangifer tarandus caribou) population of Charlevoix, Québec, Canada. Photo credit: Benjamin Larue

Figure 2

Map of the study area, showing the natal ranges of calves and the postdispersal ranges of subadults during the snow‐covered (Dec–Apr) and snow‐free seasons (May–Nov) used to study natal habitat preference induction in a boreal population of woodland caribou in Charlevoix, Québec, Canada, 2004‒2011

Figure 3

Individual selection coefficients for 6–20‐year‐old disturbances during the (a) snow‐covered (Dec–Apr) and (b) snow‐free (May – Nov) seasons in a boreal population of woodland caribou in Charlevoix, Québec, Canada, 2004‒2011. Selection coefficients were extracted from individual‐based RSFs fitted to every caribou at every life stage and season. Coefficients above and below 0 represented selection and avoidance of 6–20‐year‐old disturbances, respectively. Repeatabilities of selection coefficients for 6–20‐year‐old disturbances between individual life stages (calf =blue dots vs. subadult =orange triangles) were 0.00 and 0.54 during the snow‐covered and snow‐free seasons, respectively.