Differences in survival and behaviour of rock ptarmigan ( Lagopus mutus ) chicks among years in Alaska

• Published in: Canadian Journal of Zoology
• Main Authors: Theberge, John B., Bendell, James F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1980
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Lagopus mutus; rock ptarmigan; Alaska
• Online Access: http://dx.doi.org/10.1139/z80-225; http://www.nrcresearchpress.com/doi/pdf/10.1139/z80-225

Three successive cohorts of rock ptarmigan chicks were raised in the standard conditions of a controlled environment aviary at the University of Alaska to identify inherent differences in survival and behaviour. That such differences were occurring was suggested by analysis of 10 years of population data. Eggs and chicks less than 4 days old were collected adjacent to the Eagle Creek population study area, representing one cohort at the peak of the cyclic fluctuation in 1968, and one on each side of the peak. Survival to 8 weeks varied among years. Parallel differences occurred in survival of chicks in the wild. Differences also occurred among years in level of agonistic behaviour measured from day 1 to 8 weeks by means of mirror tests. The behavioural differences are also attributed to inherent differences between cohorts. The difference in agonistic behaviour between 1968 and 1969 was primarily due to the greater scores of chicks from adult (2 years or older) hens. In 1969, chicks from adult hens were significantly more agonistic than chicks from yearling hens.