Prevalence and mechanisms of partial migration in ungulates
- 1University of Alberta, Canada
- 2Idaho Department of Fish and Game (IDFG), United States
- 3University of Wyoming, United States
- 4University of Montana, United States
Partial migration, a phenomenon wherein only some individuals within a population migrate, is taxonomically widespread. While well-studied in birds and fish, partial migration in large herbivores has come into the spotlight only recently due to the decline of migratory behavior in ungulate species around the world. We reviewed studies describing these trends to explore both population- and individual-level mechanisms for partial migration in ungulates. We addressed how density-dependent and -independent factors, alone or together, could maintain both migrants and residents within a population. We then searched for evidence that intrinsic and extrinsic factors could combine with genetic predispositions and individual differences in temperament or life experience to promote migratory tendencies of individuals. Despite the long-held assumption that migration is a fixed behavior of individuals, evidence suggested that changes in migratory behavior result from state-dependent responses of individuals. Data are needed to demonstrate empirically which factors determine the relative costs and benefits to using migratory versus resident tactics. We outline what types of long-term data could address this need and urge those studying migration to meet these challenges in the interest of conserving partially migratory populations.
Keywords: ungulate, Partial migration, density-dependence, Frequency-dependence, condition, review
Received: 29 Mar 2019;
Accepted: 13 Aug 2019.
Copyright: © 2019 Berg, Hebblewhite, St. Clair and Merrill. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Jodi E. Berg, University of Alberta, Edmonton, Canada, email@example.com