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|Title:||The effects of dominance status on reproductive success and offspring quality in Japanese quail|
|Author(s):||Halupka, Karl C.|
|Doctoral Committee Chair(s):||Burley, Nancy|
|Department / Program:||Biology|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
Biology, Animal Physiology
|Abstract:||Behavioral dominance is a common phenomenon among vertebrates, but the relative costs and benefits associated with dominance status are not well understood. My research addressed the fitness consequences of dominance in Japanese Quail (Coturnix japonica). By measuring both reproductive success and offspring quality I sought to determine if tradeoffs occurred between these two components of fitness.
I assessed intrasexual dominance status by observing dyadic encounters and flock interactions. The most dominant and subordinate individuals from hierarchies were selected and paired in all four possible combinations of status and sex.
Dominance status did not affect overall reproductive success, but did have significant effects on mating behavior. Dominant males courted their mates more frequently and dominant females tended to be more aggressive toward their mates.
I evaluated offspring quality in a variety of ways including growth, response to cold stress, immune response, and the dominance status of offspring when they reached adulthood. Offspring of mixed status pairs had more rapid early growth and less severe response to cold stress. The immune response of offspring of subordinate parents to a coccidian parasite was significantly less effective than the response of offspring of dominant parents. Immune response to intravenous inoculation of Chukar red blood cells did not differ among offspring from different status pairing treatments. I found the heritability of dominance ability to be in the moderate range, but heritability could not be measured with great accuracy in my study due to limited sample size.
Dominance status in Japanese Quail does not affect reproductive success directly, but does have significant effects on certain important aspects of offspring quality. Interpreting the relative costs and benefits of these effects on fitness is complicated by their dependence on prevailing selection pressures. The moderate heritability of dominance ability, an extremely variable trait, and the lack of significant differences in reproductive success in relation to dominance, suggests fluctuating selection may be important in preserving this behavioral variation.
|Rights Information:||Copyright 1992 Halupka, Karl C.|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9215823|