Term of Award

Fall 2007

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Department

Department of Biology

Committee Chair

John W. Parrish

Committee Member 1

William S. Irby

Committee Member 2

Lance A. Durden

Abstract

This research involved a survey of the distribution and reproductive biology of the threatened southeastern subspecies of the American Kestrel (Falco sparverius paulus). Numbers of Southeastern American Kestrels are estimated to have declined by more than 80% over the last fifty years in the southeastern United States. In Georgia, populations have nearly disappeared below the Fall Line. The paucity of adequate nest sites is the major factor contributing to the decline of this obligate secondary cavity nester. The largest breeding population of this subspecies in Georgia is located in the south-central part of the state in the hollow cross-arms of a 230kV transmission line extending from the Offerman substation (Pierce County) in the east, to Plant Mitchell (Putney, Dougherty County, GA) in the west. Current data show this kestrel population remains stable in spite of high electromagnetic fields. Of the 373 usable transmission towers, 284 (76%) were used by breeding kestrel pairs in 2005 and 2006. The majority of the sites used for breeding occurred along the middle transect of the line where it is paralleled by an additional transmission line lacking hollow cross-arms. The study also indicated that kestrels will utilize human-made, alternative nest sites. Four of 17 (24%) and three of 17 (18%) PVC-tubes and nest boxes were used by kestrels in 2005 and 2006, respectively. Additional data from a transmission line in central Georgia (near Butler, Taylor County, GA) support this finding by showing kestrel use of nest boxes placed on replacement towers lacking potential nest sites that were erected once the hollow cross-armed transmission towers were removed. Overall, this research continues the collection of data on F.s. paulus in Georgia, providing essential demographic and reproduction data of this subspecies of concern in Georgia.

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