Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival. © 2005 NRC Canada.

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Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

Canadian Journal of Zoology ◽

10.1139/z05-034 ◽

2005 ◽

Vol 83 (3) ◽

pp. 407-418 ◽

Cited By ~ 80

Author(s):

Heiko U Wittmer ◽

Bruce N McLellan ◽

Dale R Seip ◽

James A Young ◽

Trevor A Kinley ◽

...

Keyword(s):

British Columbia ◽

Population Dynamics ◽

Rangifer Tarandus ◽

Population Decline ◽

Survival Rates ◽

Adult Survival ◽

Rangifer Tarandus Caribou ◽

Vital Rates ◽

Woodland Caribou ◽

Annual Survival

We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival.

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Seasonal distribution and population parameters of woodland caribou in central Manitoba: implications for forestry practices

Rangifer ◽

10.7557/2.20.5.1633 ◽

2000 ◽

Vol 20 (5) ◽

pp. 85 ◽

Cited By ~ 3

Author(s):

Kimberley G. Brown ◽

Campbell Elliott ◽

Francois Messier

Keyword(s):

Boreal Forest ◽

Rangifer Tarandus ◽

Seasonal Distribution ◽

Rate Of Change ◽

Adult Survival ◽

Rangifer Tarandus Caribou ◽

Population Parameters ◽

Woodland Caribou ◽

Forestry Practices ◽

Resource Exploration

Woodland caribou (Rangifer tarandus caribou) in the boreal forest are believed threatened by human encroachment and associated disturbances such as resource exploration and extraction. We radiocollared and monitored fifteen female woodland caribou in central Manitoba, from 1995 to 1997, to obtain information on their population range, seasonal distribution and movements in relation to forestry concerns. The population ranged over 4600 km2 within a large peatland system and concentrated their activities in two areas for both the summer and winter seasons. Females were relatively more solitary during the summer and exhibited fidelity to specific calving and summering areas averaging 83.4 km2. Individual wintering locations varied between years and among individuals. Post-rut and pre-calving mixed-sex aggregations occurred on the southern portion of the herds range. Caribou from the northern part of the range utilized a traditional travel corridor moving as far as 65 km to access the aggregation areas and their summer or winter ranges. Adult survival during the study period averaged 0.90 (95% CI, 0.80-1.00). Survival of the 1995 cohort appeared to be high as indicated by the 0.65:1 calf-cow ratio, and 30 ± 7% calf composition of observed caribou in the autumn of 1995. The annual rate of change (A,) of 1.19 (95% CI, 1.02-1.36) from January to November of 1995 indicated rhat the population was increasing at that time.

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Woodland caribou: Facts for forest managers

The Forestry Chronicle ◽

10.5558/tfc68481-4 ◽

1992 ◽

Vol 68 (4) ◽

pp. 481-491 ◽

Cited By ~ 24

Author(s):

H. G. Cumming

Keyword(s):

Forest Management ◽

Rangifer Tarandus ◽

Population Decline ◽

Habitat Destruction ◽

Rangifer Tarandus Caribou ◽

Woodland Caribou ◽

Mortality Factors ◽

Resource Managers ◽

Ultimate Cause ◽

Multiple Resource

A literature review points to predation as the proximate factor controlling woodland caribou (Rangifer tarandus caribou) populations in most cases, but that finding does not obviate the need for caribou to be included in forest management. Managers must consider the indirect effects of forest operations on caribou through their impacts on caribou mortality factors, such as prédation. Lichens remain important. Habitat destruction may in some cases be the ultimate cause of population decline. Reactions of caribou to disturbance vary, and remain controversial; more research is needed. Multiple resource managers of boreal commercial forests should identify sensitive components of caribou range – calving grounds, rutting locations, wintering areas, and travel routes among them – and prescribe for these areas in forest management plans. Ways of accommodating caribou in commercial forests are not well established, but some examples suggest how this might be done. Most importantly, areas that have been proven by their continued use to contain all necessary requirements for caribou survival should not be physically altered until their essential qualities and functions are better understood. Key words: Rangifer tarandus caribou, woodland caribou, predation, forest management.

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Managing second-growth forests as caribou habitat

Rangifer ◽

10.7557/2.10.3.844 ◽

1990 ◽

Vol 10 (3) ◽

pp. 139 ◽

Cited By ~ 8

Author(s):

Susan K. Stevenson

Keyword(s):

British Columbia ◽

Habitat Management ◽

Rangifer Tarandus ◽

Management Practices ◽

Rangifer Tarandus Caribou ◽

Woodland Caribou ◽

Old Growth ◽

Stand Management ◽

Second Growth ◽

Old Growth Forests

Habitat management for woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia has generally focussed on protecting old-growth forests from logging. As that strategy becomes more difficult to maintain, biologists are beginning to explore opportunities to manage second-growth stands to provide arboreal lichens and other habitat resources important to caribou. Special harvesting and stand management practices are being developed and formulated into strategies for maintaining caribou populations in managed stands.

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Factors influencing variation in site fidelity of woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia

10.26686/wgtn.12971867.v1 ◽

2020 ◽

Author(s):

Heiko Wittmer ◽

B McLellan ◽

F Hovey

Keyword(s):

British Columbia ◽

Site Fidelity ◽

Rangifer Tarandus ◽

Snow Accumulation ◽

Limiting Factors ◽

Late Winter ◽

Behavioural Plasticity ◽

Rangifer Tarandus Caribou ◽

Early Winter ◽

Woodland Caribou

Where predation is a major limiting factor, it has been postulated that woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual's distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter. © 2006 NRC.

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Factors influencing variation in site fidelity of woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia

Canadian Journal of Zoology ◽

10.1139/z06-026 ◽

2006 ◽

Vol 84 (4) ◽

pp. 537-545 ◽

Cited By ~ 33

Author(s):

Heiko U. Wittmer ◽

Bruce N. McLellan ◽

Frederick W. Hovey

Keyword(s):

British Columbia ◽

Site Fidelity ◽

Rangifer Tarandus ◽

Snow Accumulation ◽

Limiting Factors ◽

Late Winter ◽

Behavioural Plasticity ◽

Rangifer Tarandus Caribou ◽

Early Winter ◽

Woodland Caribou

Where predation is a major limiting factor, it has been postulated that woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual’s distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter.

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Reply to the comment by Harron on “Widespread declines in woodland caribou (Rangifer tarandus caribou) continue in Alberta”

Canadian Journal of Zoology ◽

10.1139/cjz-2014-0321 ◽

2015 ◽

Vol 93 (2) ◽

pp. 151-154 ◽

Cited By ~ 2

Author(s):

D. Hervieux ◽

M. Hebblewhite ◽

N.J. DeCesare ◽

M. Russell ◽

K. Smith ◽

...

Keyword(s):

Rangifer Tarandus ◽

Original Study ◽

Rangifer Tarandus Caribou ◽

Vital Rates ◽

Woodland Caribou ◽

Protected Species ◽

Demographic Trends ◽

Powerful Means ◽

Conservation Actions ◽

Study Species

Estimation of demographic trends from vital rates provides a powerful means to estimate population trends in cryptic or difficult to study species such as woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). Using such methods, Hervieux et al. (2013; Can. J. Zool. 91(12): 872–882) recently showed 11 of 14 woodland caribou populations in Alberta were declining at ∼8%/year following up to 18 years of monitoring. Harron (2015; Can. J. Zool. 93(2): 149–150) critiques our original study, claiming that negative biases in our demographic monitoring exaggerate our conclusions of widespread caribou declines. Here, we systematically review each of Harron’s claims of bias, rejecting each of his claims upon careful review of the mechanisms by which his purported claims would manifest in our population trend estimation. Therefore, we conclude that Harron’s scientific critique was superficial and misleading. Delays in conservation actions raised by Harron’s critique risk diminishing opportunities to conserve and recover this federally and provincially protected species.

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Population dynamics of the black-cheeked gnateater (Conopophaga melanops, Conopophagidae) in southern Brazil

Journal of Tropical Ecology ◽

10.1017/s0266467409990289 ◽

2009 ◽

Vol 25 (6) ◽

pp. 605-613 ◽

Cited By ~ 3

Author(s):

André Magnani Xavier de Lima ◽

James Joseph Roper

Keyword(s):

Population Dynamics ◽

Population Growth ◽

Breeding Season ◽

Survival Rates ◽

Territory Size ◽

Adult Survival ◽

Southern Brazil ◽

Annual Survival ◽

Socially Monogamous ◽

Population Structure And Dynamics

Abstract:Population structure and dynamics of the black-cheeked gnateater (Conopophaga melanops) were studied at Salto Morato Nature Reserve, in Paraná, southern Brazil, from October 2006 to September 2007. Territory size and population density, breeding season (timing and length), reproductive success and annual survival rates were estimated from sightings of 18 marked adult birds and the success of 18 nesting attempts. The black-cheeked gnateater is socially monogamous and territorial, with a breeding-season length of approximately 3 mo beginning in early October. Predation caused most nest failures, nest survival was 0.96 d−1and apparent annual nesting success was 22%, resulting in annual productivity of 0.36 individuals per adult. Apparent adult annual survival was ~0.44 y−1. Seventy-five per cent of fledglings survived at least 2 mo after fledging. Two methods of estimating population growth rate suggest very different rates: r = −0.04 (~ stable), or λ varies between 0.475–0.616 (declining). Yet, low apparent adult survival suggests that territories are not permanent, perhaps abandoned after nest failure. We find that by estimating population growth, even in short-term studies, testable hypotheses can be generated that will allow better understanding of population dynamics.

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Survival of radio-collared caribou (Rangifer tarandus caribou) from the George River herd, Nouveau-Québec – Labrador

Canadian Journal of Zoology ◽

10.1139/z90-041 ◽

1990 ◽

Vol 68 (2) ◽

pp. 276-283 ◽

Cited By ~ 11

Author(s):

Brian J. Hearn ◽

Stuart N. Luttich ◽

Michel Crête ◽

Maria B. Berger

Keyword(s):

Cause Of Death ◽

Rangifer Tarandus ◽

Survival Rates ◽

Rangifer Tarandus Caribou ◽

Annual Survival ◽

Lower Survival ◽

Fecundity Rate ◽

Rate Of Increase ◽

George River ◽

Age And Sex

Between September 1983 and June 1987, 175 caribou (Rangifer tarandus caribou) from the George River caribou herd were captured and radio-collared. By October 1987, 42 of those had died: 15 were apparently killed by predators, 8 were legally shot, 4 appeared to have died proximally from malnutrition, 1 died from an accident, and cause of death could not be determined for 14 others. Seasonal and annual survival rates were estimated most precisely for adult (≥ 24 months) females, but a consistent trend towards lower survival at the end of the study period was evident in all age and sex groups. Decreasing summer survival was responsible for the lowering of annual survival rates, as winter survival was relatively constant over the study period. Using our calculated age-specific survival rates, and estimates of age-specific fecundity, the survival–fecundity rate of increase (rs) for the female segment of the herd was 0.12 for 1983–1984 and −0.01 for 1986–1987. Decreasing summer survival thus appears to have been of greatest importance in reducing rs to zero and halting the growth of the herd. Density-dependent mechanisms acting on the George River caribou herd appear different from those described for caribou herds regulated by winter forage.

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