Data from: Many places called home: the adaptive value of seasonal adjustments in range fidelity

1. The vast majority of animal species display range fidelity, a space-use
behaviour enhancing familiarity with local habitat features. While the
fitness benefits of this behaviour have been demonstrated in a variety of
taxa, some species or populations rather display infidelity, displacing
their home range over time. Others, such as many ungulate species, show
seasonal adjustments in their range fidelity to accommodate changes in the
dominance of limiting factors or in the distribution of resources. 2. Few
empirical studies have explored the adaptive value of seasonal adjustments
in range fidelity. Using boreal populations of woodland caribou (Rangifer
tarandus caribou) as a biological model, we evaluated how range fidelity
impacted individual performance during two seasons where juvenile and
adult survival are limited by different predation pressures. 3. Between
2004 and 2013, we monitored the survival, reproductive success, habitat
selection and range fidelity of female caribou in the boreal forest of
eastern Canada. Using resource selection functions, we assessed how
seasonal range fidelity was linked to two fitness correlates: calf
survival in summer and adult female survival in winter. 4. Females
displayed season-specific space use tactics: they selected previously used
areas during calving and summer, but tended to shift their winter range
from one year to the next. During calving and summer, range fidelity
yielded relatively high fitness benefits, as females that did not lose
their calf displayed stronger fidelity than females that did. In winter,
however, adult survival was negatively linked to range fidelity, as
females that survived selected areas further away from their seasonal
range of the previous year than females that died. 5. We provide one of
the first evidences that making seasonal adjustments in range fidelity can
be an adaptive behaviour influencing the spatial distribution of a
threatened species. Assessing the seasonal nature of range fidelity
tactics may improve our predictions of space use and associated fitness
implications for species displaying this behaviour.