Date of Award

Summer 2015

Access Restriction

Thesis

Degree Name

Master of Science

Department

Environmental Science & Civil Engineering

School or College

Seaver College of Science and Engineering

First Advisor

Eric G. Strauss

Second Advisor

John H. Dorsey

Third Advisor

Peter J. Auger

Abstract

The response of American crows (Corvus brachyrhynchos) to electrified eggs at the Venice Beach California least tern nesting colony was monitored throughout the 2014 season. Game cameras were deployed beside the artificial nests to record crow behavior towards the electrified eggs. Conditioned crows were defined as crows that were present within <15 feet but >1 foot of the electrified eggs and unconditioned crows were considered crows that were present within 1 foot of the eggs. The number of conditioned crows observed in the video clips significantly differed from a homogenous distribution using a chi-square test (p<0.001). The first 5 weeks of the experiment experienced a larger number of unconditioned crows than the remaining weeks of the experiment. A modified approach to the Lincoln index was also used to estimate population flux of crows at the Venice Beach colony. The nesting California least terns at Venice Beach successfully produced fledges when this predator aversion experiment was deployed, after 5 years of no reproductive success and the 2014 fledging per pair ratio was the second highest ratio recorded in 2013 and 2014. Further multi-year research is needed to clarify the efficacy of this management intervention as there may be associated confounding variables.

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