| Summary: | 碩士 === 國立臺灣師範大學 === 生命科學研究所 === 101 === Injury Feigning, is a kind of bird behaviors of nest defenses. There is two hypothesis referring optimal timing of nest defense: (1) Brood value hypothesis. (2) Vulnerability hypothesis. In this study, I focus on demonstrating the difference of the injury feigning behaviors which take by semi-precocial Savanna Nightjars (Caprimulgus affinis) during different ages, to test the timing, frequency, and settling distance. The study sites include river banks (with cover) and building rooftops (without cover). During 2008-2012, we recorded 54 nests at building rooftops and 69 at river banks (breeding success age: 17 days old). At building rooftops, female began to display injury feigning behaviors when nestlings were 4 days old. And the frequency of this behaviors reached a peak at 6-9 days old (weighted average:7.9 days old). At river banks, female began to display injury feigning behaviors when nestlings were 5 day old. And the frequency of this behaviors reached a peak at 8-11 days old (weighted average:9.0 days old). In both environments, the timing of injury feigning is highly related to the days of nestlings usually moved(river banks：rs=0.921, building rooftops：rs= 0.932). Besides, females displayed injury feigning behaviors early and longer at the uncover site. The older females displayed more injury feigning than the youngers at the uncover surroundings. The difference of timing and sites which females displayed injury feigning behaviors, may be refered to the environment cover provides different protection on nestlings.
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