| Abstract: | Calf mortality is major component of caribou population dynamics, but
little is known about the timing or causes of calf losses, or of
characteristics that predispose calves to mortality. During 1984-87,
we radiocollared 226 calves (less than or equal to 3 days old) in the
Denali Caribou Herd (DCH), an unhunted population utilized by a
natural complement of predators, to determine the extent, timing, and
causes of calf mortality and to evaluate influences of year, sex,
birthdate, and birth mass on those losses. Overall, 39% of
radio-collared calves died as neonates (less than or equal to 15 days
old), and 98% of those deaths were attributed to predation. Most
neonatal deaths (85%) occurred within 8 days of birth. Few deaths
occurred after the neonatal period (5, 10, and 0% of calves
instrumented died during 16-30, 31-150, and greater than 150 days of
age, respectively). Survival of neonates was lower (P = 0.038) in
1985, following a severe winter, than during the other 3 years. In
years other than 1985, calves born during the peak of calving (approx
50% of the total, born 5-8 days after calving onset) experienced
higher (P less than 0.001) neonatal survival than did other calves.
Grizzly bears, wolves, and unknown large predators (i.e., grizzly
bears or wolves) accounted for 49, 29, and 16% of the neonatal deaths,
respectively. The rate of bear-caused mortalities declined (P less
than 0.001) with calf age, and bears killed few calves greater than 10
days old. Wolf predation was not related (P greater than 0.05) to
calf age and peaked 10 days after onset of calving. Grizzly bear and
wolf predation on neonates during the calving season was a limiting
factor for the DCH. |
| Genre: | Article |
| ProdID: | 1012894 |
| Citation Author: | Adams, L. G.; Singer, F. J.; Dale, B. W. |
| Citation Contributing Office: | Alaska Biological Science Center |
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| Citation End Page: | 594 |
| Citation Issue: | 3 |
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| Citation Language: | English |
| Citation Larger Work Title: | Journal of Wildlife Management |
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| Citation Number Of Pages: | 11 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | pp. 584-594 |
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| Citation Search Results Text: | Caribou calf mortality in Denali National Park, Alaska; 1995; Article; Journal; Journal of Wildlife Management; Adams, L. G.; Singer, F. J.; Dale, B. W. |
| Citation Start Page: | 584 |
| Citation Volume: | 59 |
| Citation Year: | 1995 |
| Type: | citation/reference |
| Text: | Caribou calf mortality in Denali National Park, Alaska; 1995; Article; Journal; Journal of Wildlife Management; Adams, L. G.; Singer, F. J.; Dale, B. W. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Sun, 1 Jan 1995 00:00 -0600 |
| Publisher: | |
