Date of Award

5-2011

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Biology

Thesis Sponsor/Dissertation Chair/Project Chair

John A. Smallwood

Committee Member

Scott L. Kight

Committee Member

John J. Gaynor

Abstract

American kestrel (Falco sparverius) populations throughout much of the United States have exhibited a substantial decline during recent years. Prompted by this decline, I designed this study to determine if removing arthropod parasites from nestlings was an effective strategy in increasing the breeding success of American kestrels, as well as to identify and quantify the ectoparasites found on nestlings. I conducted the study in Sussex and Warren counties in northwestern New Jersey in conjunction with a nest box program established and monitored by J. A. Smallwood and his students (hereafter referred to as we). I removed parasites periodically from all chicks in 13 experimental broods and only once from chicks in 11 control broods. I checked all nest boxes where chicks hatched during each of the following intervals: 5-7, 10-12, 15-17, and 20-22 days from hatching of the first chick. I removed and handled all chicks from the nest boxes during each visit. I removed parasites from experimental chicks during each of the four visits, and from control chicks only during the final visit during days 20-22. Parasite removal from both control and experimental chicks during the final visit allowed for a comparison of parasite loads between the two groups. During the final visit, we banded all chicks and measured the length of the right seventh primary feather (wing length), length of the right outer tail feather (tail length), and weight of each chick. I performed a principal component analysis using wing length, tail length, and the cube root of weight to condense these three variables into one measure of chick size. I also calculated weight/wing length for each chick as an index of chick health condition, as wing length is mostly dependent on age and chick weight is dependent on chick health as well as age. I collected a total of 1767 arthropod specimens, 1679 (95.0%) of which were Camus hemapterus Nitzsh (Diptera: Carnidae). The remaining 88 specimens included 59 parasites, 2 parasitoids, 10 detritivores, and 17 incidental species (species not know to be parasitic, eg. herbivores). C. hemapterus loads per chick increased as chicks aged, were highest during the 10-12 day interval, and declined thereafter. I found differences in size (weight and principle component one) between male and female kestrels, so I treated males and females as separate groups. I used four groups for the analysis, control males (n = 11 broods), control females {n = 9 broods), experimental males (n = 13 broods), and experimental females («=11 broods). C. hemapterus loads and other parasite loads during the final check were significantly higher for experimental broods. I did not find any significant differences between control and experimental broods for wing length, tail length, weight, principal component one, or weight/wing length. Ectoparasite removal would not be an effective strategy in increasing the breeding success of American kestrels in this study area.

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