Webinar - Effectiveness of Population-Based Recovery Actions for Threatened Southern Mountain Caribou

Authors
Clayton Lamb
Sara Williams
Stan Boutin
Michael Bridger
Deborah Cichowski
Kristina Cornhill
Craig DeMars
Melanie Dickie
Bevan Ernst
Adam Ford
Michael Gillingham
Laura Greene
Douglas Heard
Mark Hebblewhite
Dave Hervieux
Mike Klaczek
Bruce McLellan
Scott McNay
Lalenia Neufeld
Barry Nobert
Joshua Nowak
Agnes Pelletier
Caroline Seip
Carolyn Shores
Robin Steenweg
Shane White
Heiko Wittmer
Mark Wong
Kathryn Zimmerman
Robert Serrouya
Contacts
Resource Date:
2024

Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population’s range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973–2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population-based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.