Population dynamics of caribou herds in southwestern Alaska

Valkenburg, Patrick; Sellers, Richard A.; Squibb, Ronald C.; Woolington, James D.; Aderman, Andrew R.; Dale, Bruce W.

doi:10.7557/2.23.5.1694

Cited by 11 publications

(10 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These controlled experiments quantified how nutrition affects performance and identified thresholds of performance useful for helping to understand the role of nutrition in wild elk populations. We integrated our assessment of nutritional Klein (1970) Caribou/muskoxen Juvenile growth Bobek (1977) Roe deer Population numbers White (1983) Arctic grazers Reproduction, survival, growth Reimers et al (1983) Caribou/reindeer Juvenile growth, body mass, calving time Verme and Ullrey (1984) White-tailed deer Reproduction, survival, growth Saether (1985) Moose Body mass Messier et al (1988) Caribou/reindeer Population numbers, reproduction Huot (1989) Caribou/reindeer Body composition Cook (1990) Bighorn sheep Juvenile survival Saether and Heim (1993) Moose Juvenile growth, age of maturation Couturier et al (1990) Caribou/reindeer Population numbers, reproduction Bø and Hjeljord (1991) Moose Body mass Lavigueur and Barrette (1992) Caribou/reindeer Juvenile growth Caribou/reindeer Body composition, juvenile growth, milk production, survival, reproduction Caribou/reindeer Reproduction, growth, body composition Langvatn et al (1996) Red deer Age at first breeding Crête and Courtois (1997) Moose Calf production Gerhart et al (1996) Caribou/reindeer Reproduction Hjeljord and Histol (1999) Moose Body mass Parker et al (1999) Black-tailed deer Body composition Post and Klein (1999) Caribou/reindeer Reproduction, juvenile survival Solberg et al (1999) Moose Calf recruitment, population growth Mysterud et al (2001) Red deer Body mass Ericsson et al (2002) Moose Juvenile growth Peek et al (2002) Mule deer Population numbers Valkenburg et al (2003) Caribou/reindeer Juvenile growth Cameron et al (2005) Caribou/reindeer Reproduction, body composition Herfindal et al (2006a, b) Moose Body mass Tollefson (2007) Mule deer Body composition, juvenile growth, milk production, reproduction Dale et al (2008) Caribou/reindeer Juvenile growth Post and Forchhammer (2008) Caribou/rein...…”

Section: Introductionmentioning

confidence: 99%

Regional and seasonal patterns of nutritional condition and reproduction in elk

Cook

Vales³

et al. 2013

Wildlife Monographs

119

245

View full text Add to dashboard Cite

Demographic data show many populations of Rocky Mountain (Cervus elaphus nelsoni) and Roosevelt (Cervus elaphus roosevelti) elk have been declining over the last few decades. Recent work suggests that forage quality and associated animal nutritional condition, particularly in late summer and early autumn, influence reproduction and survival in elk. Therefore, we estimated seasonal nutritional condition of 861 female elk in 2,114 capture events from 21 herds in Washington, Oregon, Wyoming, Colorado, and South Dakota from 1998 to 2007. We estimated ingesta-free body fat and body mass, and determined age, pregnancy status, and lactation status. We obtained estimates for most herds in both late winter-early spring (late Feb-early Apr) and in autumn (Nov-early Dec) to identify changes in nutritional condition of individuals across seasons.Body fat levels of lactating females in autumn were consistently lower than their non-lactating counterparts, and herd averages of lactating elk ranged from 5.5% to 12.4%. These levels were 30-75% of those documented for captive lactating elk fed high-quality diets during summer and autumn. Body fat levels were generally lowest in the coastal and inland northwest regions and highest along the west-slope of the northern Cascades. Adult females in most herds lost an average of 30.7 kg (range: 5-62 kg), or about 13% (range: 2.6-25%) of their autumn mass during winter, indicating nutritional deficiencies. However, we found no significant relationships between spring body fat or change in body fat over winter with winter weather, region, or herd, despite markedly different winter weather among herds and regions. Instead, body fat levels in spring were primarily a function of fat levels the previous autumn. Thinner females in autumn lost less body fat and body mass over winter than did fatter females, a compensatory response, but still ended the season with less body fat than the fatter elk.Body fat levels of lactating females in autumn varied among herds but were unrelated to their body fat levels the previous spring. Within herds, thinner females exhibited a compensatory response during summer and accrued more fat than their fatter counterparts over summer, resulting in similar body fat levels among lactating elk in autumn despite considerable differences in their fat levels the previous spring. Level of body fat achieved by lactating females in autumn varied 2-fold among herds, undoubtedly because of differences in summer nutrition. Thus, summer nutrition set limits to rates of body fat accrual of lactating females that in turn limited body condition across the annual cycle.Pregnancy rates of 2-to 14-year-old females ranged from 68% to 100% in coastal populations of Washington, 69% to 98% in Cascade populations of Washington and Oregon, 84% to 94% in inland northwestern populations of Washington and Oregon, and 78% to 93% in Rocky Mountain populations. We found evidence of late breeding, even in herds with comparatively high pregnancy rates. Mean body mass of calves (n ¼ 242) in 3 popul...

show abstract

Section: Introductionmentioning

confidence: 99%

Regional and seasonal patterns of nutritional condition and reproduction in elk

Cook

Vales³

et al. 2013

Wildlife Monographs

119

245

View full text Add to dashboard Cite

show abstract

“…Some Rangifer populations in southwestern Alaska exhibit a 40-to 50-year periodicity (16), whereas in Greenland some Rangifer populations have a periodicity of 65-115 years (17). Peary caribou in the Canadian High Arctic have exhibited a relatively short 20-year periodicity (18).…”

Section: Rangifer Fluctuations In Abundance and Human Demographymentioning

confidence: 99%

Evidence for declines in human population densities during the early Upper Paleolithic in western Europe

Morin

2008

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

In western Europe, the Middle to Upper Paleolithic (M/UP) transition, dated between Ϸ35,000 and Ϸ40,000 radiocarbon years, corresponded to a period of major human biological and cultural changes. However, information on human population densities is scarce for that period. New faunal data from the high-resolution record of Saint-Cé saire, France, indicate an episode of significant climatic deterioration during the early Upper Paleolithic (EUP), which also was associated with a reduction in mammalian species diversity. High correlations between ethnographic data and mammalian species diversity suggest that this shift decreased human population densities. Reliance on reindeer (Rangifer tarandus), a highly fluctuating resource, would also have promoted declines in human population densities. These data suggest that the EUP represented for humans a period of significant niche contraction in western Europe. In this context, the possibility that a modern human expansion occurred in this region seems low. Instead, it is suggested that population bottlenecks, genetic drift, and gene flow prevailed over human population replacement as mechanisms of evolution in humans during the EUP.archaeology ͉ Rangifer ͉ Middle to Upper Paleolithic transition ͉ modern human origins ͉ Neandertals

show abstract

“…In the Alaskan mountains, there are two examples of herds with increasing population sizes that shifted their calving grounds. The new calving ground overlapped the calving area of a smaller and neighbouring herd Valkenburg et al, 2003;Hinkes et al, 2005). Although information on caribou densities on the calving grounds is not available, it is reasonable to assume that they were high for the larger herd.…”

Section: Discussionmentioning

confidence: 99%

“…The two reported instances are from the Alaskan mountains, where the calving grounds of two large caribou herds shifted <25 km and engulfed the dispersed calving sites of two small herds Valkenburg et al, 2003;Hinkes et al, 2005).…”

mentioning

confidence: 99%

A conceptual model for migratory tundra caribou to explain and predict why shifts in spatial fidelity of breeding cows to their calving grounds are infrequent

Gunn¹,

Poole²,

Nishi³

2012

Ran

View full text Add to dashboard Cite

Calving grounds of migratory tundra caribou (Rangifer tarandus) have two prominent characteristics. Firstly, the cows are gregarious, and secondly, the annual calving grounds spatially overlap in consecutive years (spatial fidelity). The location of consecutive annual calving grounds can gradually shift (either rotationally or un-directional) or more rarely, abruptly (non-overlapping). We propose a mechanism to interpret and predict changes in spatial fidelity. We propose that fidelity is linked to gregariousness with its advantages for individual fitness (positive density-dependence). Our argument is based on a curvilinear relationship between the density of cows on the calving ground (which we use to index gregariousness) and spatial fidelity. Extremely high or low densities are two different mechanisms which can lead to reduced spatial fidelity to annual calving grounds and reflect the caribou's adaptive use of its calving ranges.

show abstract

Population dynamics of caribou herds in southwestern Alaska

Cited by 11 publications

References 9 publications

Regional and seasonal patterns of nutritional condition and reproduction in elk

Regional and seasonal patterns of nutritional condition and reproduction in elk

Evidence for declines in human population densities during the early Upper Paleolithic in western Europe

A conceptual model for migratory tundra caribou to explain and predict why shifts in spatial fidelity of breeding cows to their calving grounds are infrequent

Contact Info

Product

Resources

About