Wolf Predation on the Nelchina Caribou Herd: A Reply
Bergerud AT and Ballard WB. 1989. Wolf Predation on the Nelchina Caribou Herd: A Reply. The Journal of Wildlife Management. 53(1):251-259
We review arguments on the roles of wolf predation and winter starvation in recruitment of the Nelchina caribou (Rangifer tarandus) herd, Alaska. Van Ballenberghe (1985) originally proposed that high calf mortality in the 1960's and 1971-72 was caused by winter severity and that wolf (Canis lupus) predation played a minor role. Van Ballenberghe (1989) now argues that the data are not adequate to decide between hypotheses, and winter starvation is no longer stressed as the valid explanation for low calf survival. His basis for arguing that predation played a minor role in calf survival was that the wolf population was low and stable from 1962 to 1974 (Van Ballenberghe 1985:fig. 2). However, he revised 9 of 10 original estimates and incorporated them into a graph where there were no estimates for 15 years. Original estimates indicated that the wolf population increased at a finite rate of 1.30 from 1953 to 1965, and wolf population estimates based on original census data were negatively correlated with recruitment (Bergerud and Ballard 1988). Additionally, recruitment improved 3 times when wolf populations were reduced through hunting and removal programs. The decline of the Nelchina herd from 1962 to 1972 can be explained by excessive human harvests in the absence of adequate recruitment.
- Type
- Journal Article
- Authors
- Bergerud, A; Ballard, W
- Units
- CAKN , DENA , WRST
- Keywords
- Canis lupus, Caribou, Copper River Basin, GMU 13, Mortality, Nelchina, Population Dynamics, Predation, Rangifer tarandus, Recruitment, Wolves