Behavioral plasticity allows ungulates to balance risk and reward following megafire

Abstract

Anthropogenic climate and land use change has accelerated the frequency of extreme climatic disturbances such as megafire. These megafires dramatically alter ecosystems and threaten the long-term conservation of economically and ecologically important species, including native ungulates. Recent work suggests that ungulate species may be able to adjust to the immediate effects of megafire by adjusting their movement and behavior, but whether these adjustments persist or change over time following these major disturbances is far less is understood. We take advantage of a rare research opportunity to examine how a dominant ungulate species, black-tailed deer (Odocoileus hemionus columbianus), adjusts its movement and behavior immediately following a megafire. We collected GPS data from 24 individual doe over the course of a year and fit these data to resource selection functions (RSFs) and hidden Markov movement models (HMMs) to assess whether and how deer alter habitat selection and behavioral decisions to adjust to novel landscape conditions following this megafire. We found compelling evidence of adaptive capacity across black-tailed deer following megafire, with deer modifying their habitat usage and behavior following megafire. Deer avoided exposed (chaparral) and severely burned areas immediately following megafire, but later altered these behaviors to eventually select for areas that burned at higher severities to potentially take advantage of enhanced forage in these recovering areas. These results suggest that despite their high site fidelity, this deer population, and similar ungulate species, can effectively navigate altered landscapes to track relatively sudden shifts in predation risk and resource availability. The successful adjustment of dominant ungulate species to extreme disturbances such as these could help facilitate resilience at broader ecological and trophic scales.