Repeatable nest defense behavior in a wild populat

Authors: Jennifer L Burtka Jennifer L Grindstaff

Publish Date: 2013/01/22

Volume: 16, Issue: 3, Pages: 135-146

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Abstract

Consistent individual differences in behavior or personality have been demonstrated in a variety of species other than humans including mammals birds and invertebrates Behavioral consistency has been shown to affect dispersal foraging exploration and antipredator responses which may have an impact on parental and offspring survival Despite increasing research in behavioral consistency the repeatability of nest defense behavior has rarely been assessed in wild bird populations Furthermore previous studies investigating nest defense behavior have utilized laboratory studies or mounted predators to elicit defensive behavior It is important to assess personality in wild populations to fully understand the fitness consequences of behavioral consistency across natural contexts and to utilize live predators or competitors for accurate assessment of defensive behavior We used an ecologically relevant live invasive nest site competitor the house sparrow Passer domesticus to elicit nest defense behavior in a wild population of Eastern bluebirds Sialia sialis to determine if nest defense behavior is repeatable within and between years for males and females males 2009 N = 17 2010 N = 18 both years N = 9 Females 2009 N = 22 2010 N = 15 both years N = 11 We also determined if individual behavior changes as a function of season parental age brood size or the number of house sparrows around the nest site We found that females demonstrated repeatable behavior both within and between years Male nest defense behavior was only repeatable in 1 year and was influenced by season in the other year Parental age brood size and the number of house sparrows around the nest site did not affect nest defense behavior We conclude that Eastern bluebirds demonstrate consistent nest defense behavior or personality although males are more plastic than femalesWe would like to thank our field technicians and volunteers for help with this project in particular Emily Clark Erin LaVasque and Brian Hidden We also thank Dr Craig Davis for advice on sparrow point counts Funding was provided by Bob and Julia Bollinger the Oklahoma Ornithological Society the Payne County Audubon Society and the Department of Zoology at Oklahoma State University

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