1
|
Lamb CT, Williams S, Boutin S, Bridger M, Cichowski D, Cornhill K, DeMars C, Dickie M, Ernst B, Ford A, Gillingham MP, Greene L, Heard DC, Hebblewhite M, Hervieux D, Klaczek M, McLellan BN, McNay RS, Neufeld L, Nobert B, Nowak JJ, Pelletier A, Reid A, Roberts AM, Russell M, Seip D, Seip C, Shores C, Steenweg R, White S, Wittmer HU, Wong M, Zimmerman KL, Serrouya R. Effectiveness of population-based recovery actions for threatened southern mountain caribou. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2024; 34:e2965. [PMID: 38629596 DOI: 10.1002/eap.2965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/12/2023] [Accepted: 12/20/2023] [Indexed: 06/04/2024]
Abstract
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.
Collapse
Affiliation(s)
- Clayton T Lamb
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Sara Williams
- Wildlife Biology Program, University of Montana, Missoula, Montana, USA
| | - Stan Boutin
- Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Bridger
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | | | - Kristina Cornhill
- Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Craig DeMars
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
| | - Melanie Dickie
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Bevan Ernst
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Adam Ford
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
- Department of Biology, University of British Columbia, Kelowna, British Columbia, Canada
| | - Michael P Gillingham
- Ecosystem Science and Management, University of Northern British Columbia, Prince George, British Columbia, Canada
| | - Laura Greene
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Douglas C Heard
- Tithonus Wildlife Research, Prince George, British Columbia, Canada
| | - Mark Hebblewhite
- Wildlife Biology Program, University of Montana, Missoula, Montana, USA
| | - Dave Hervieux
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Mike Klaczek
- Ministry of Forests, Government of British Columbia, Victoria, British Columbia, Canada
| | - Bruce N McLellan
- International Union for the Conservation of Nature Bear Specialist Group, D'Arcy, British Columbia, Canada
| | - R Scott McNay
- Wildlife Infometrics Inc., Mackenzie, British Columbia, Canada
| | | | - Barry Nobert
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | | | - Agnès Pelletier
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Aaron Reid
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Anne-Marie Roberts
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Mike Russell
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Dale Seip
- Ministry of Environment, Government of British Columbia, Fort St. John, British Columbia, Canada
| | - Caroline Seip
- Alberta Environment and Protected Areas, Government of Alberta, Grande Prairie, Alberta, Canada
| | - Carolyn Shores
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Robin Steenweg
- Canadian Wildlife Service, Environment and Climate Change Canada, Kelowna, British Columbia, Canada
| | - Shane White
- Ministry of Forests, Government of British Columbia, Victoria, British Columbia, Canada
| | - Heiko U Wittmer
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Mark Wong
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Kathryn L Zimmerman
- Ministry of Water, Land and Resource Stewardship, Government of British Columbia, Victoria, British Columbia, Canada
| | - Robert Serrouya
- Wildlife Science Center, Biodiversity Pathways, Kelowna, British Columbia, Canada
| |
Collapse
|
3
|
McFarlane S, Manseau M, Jones TB, Pouliot D, Mastromonaco G, Pittoello G, Wilson PJ. Identification of familial networks reveals sex-specific density dependence in the dispersal and reproductive success of an endangered ungulate. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.956834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Density is an important demographic parameter that is commonly overlooked in studies of wild populations. Here, we examined the effects of variable spatially explicit density on a range of demographic parameters in a wild population of a cryptic ungulate, boreal woodland caribou (Rangifer tarandus caribou). Using non-invasive genetic sampling, we applied spatial capture–recapture methods with landscape covariates to estimate the density of boreal woodland caribou across a 108,806 km2 study area. We then created a familial network from the reconstructed parent–offspring relationships to determine whether spatial density influenced sex-specific individual reproductive success, female pregnancy status, and dispersal distance. We found that animal density varied greatly in response to land cover types and disturbance; animal density was most influenced by landscape composition and distance to roads varying from 0 in areas with >20% deciduous cover to 270 caribou per 1,000 km2 in areas presenting contiguous older coniferous cover. We found that both male and female reproductive success varied with density, with males showing a higher probability of having offspring in higher-density areas, and the opposite for females. No differences were found in female pregnancy rates occurring in high- and low-density areas. Dispersal distances varied with density, with offspring moving shorter distances when parents were found in higher-density areas. Familial networks showed lower-closeness centrality and lower-degree centrality for females in higher-density areas, indicating that females found in higher-density areas tend to be less broadly associated with animals across the range. Although high-density areas do reflect good-quality caribou habitat, the observed decreased closeness and degree centrality measures, dispersal rates, and lower female recruitment rates suggest that remnant habitat patches across the landscape may create population sinks.
Collapse
|
6
|
DeMars CA, Gilbert S, Serrouya R, Kelly AP, Larter NC, Hervieux D, Boutin S. Demographic responses of a threatened, low-density ungulate to annual variation in meteorological and phenological conditions. PLoS One 2021; 16:e0258136. [PMID: 34624030 PMCID: PMC8500449 DOI: 10.1371/journal.pone.0258136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/17/2021] [Indexed: 11/30/2022] Open
Abstract
As global climate change progresses, wildlife management will benefit from knowledge of demographic responses to climatic variation, particularly for species already endangered by other stressors. In Canada, climate change is expected to increasingly impact populations of threatened woodland caribou (Rangifer tarandus caribou) and much focus has been placed on how a warming climate has potentially facilitated the northward expansion of apparent competitors and novel predators. Climate change, however, may also exert more direct effects on caribou populations that are not mediated by predation. These effects include meteorological changes that influence resource availability and energy expenditure. Research on other ungulates suggests that climatic variation may have minimal impact on low-density populations such as woodland caribou because per-capita resources may remain sufficient even in “bad” years. We evaluated this prediction using demographic data from 21 populations in western Canada that were monitored for various intervals between 1994 and 2015. We specifically assessed whether juvenile recruitment and adult female survival were correlated with annual variation in meteorological metrics and plant phenology. Against expectations, we found that both vital rates appeared to be influenced by annual climatic variation. Juvenile recruitment was primarily correlated with variation in phenological conditions in the year prior to birth. Adult female survival was more strongly correlated with meteorological conditions and declined during colder, more variable winters. These responses may be influenced by the life history of woodland caribou, which reside in low-productivity refugia where small climatic changes may result in changes to resources that are sufficient to elicit strong demographic effects. Across all models, explained variation in vital rates was low, suggesting that other factors had greater influence on caribou demography. Nonetheless, given the declining trajectories of many woodland caribou populations, our results highlight the increased relevance of recovery actions when adverse climatic conditions are likely to negatively affect caribou demography.
Collapse
Affiliation(s)
- Craig A. DeMars
- Caribou Monitoring Unit, Alberta Biodiversity Monitoring Institute, Edmonton, AB, Canada
- * E-mail:
| | - Sophie Gilbert
- Department of Fish & Wildlife Sciences, University of Idaho, Moscow, ID, United States of America
| | - Robert Serrouya
- Caribou Monitoring Unit, Alberta Biodiversity Monitoring Institute, Edmonton, AB, Canada
| | - Allicia P. Kelly
- Department of Environment and Natural Resources, Government of Northwest Territories, Fort Smith, NT, Canada
| | - Nicholas C. Larter
- Department of Environment and Natural Resources (retired), Government of Northwest Territories, Fort Simpson, NT, Canada
| | - Dave Hervieux
- Alberta Environment and Parks, Grande Prairie, AB, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|