Master's Theses

Date of Award

Summer 1964

Degree Name

Master of Science (MS)

Department

Biology

Advisor

Charles A. Ely

Abstract

This research is a descriptive study of an isolated colony of common grackles, Quiscalus guiscula (Linnaeus), through two nesting seasons. The objectives of the study are: (1) to study the nesting habits of the common grackle in Western Kansas, and (2) to study the growth of the young from hatching to fledging. Field work was conducted from the time the birds arrived in the spring until they left the area at the completion of the nesting season in 1963 and until June 30, 1964. Searches were made twice a week for nests by slowly walking through the area, and the history of each located nest was followed closely. Field records were kept on nesting heights, egg laying, incubation, hatching, predation, growth of the young, fledging, and behavior of the young and adults. Seventy- four nests and 246 eggs were recorded during the 1963 and 1964 nesting seasons with 66 nests and 212 eggs being followed to completion. Nesting success from the 66 nests was 34.8 percent, hatching success from the 212 eggs was 46.7 percent, and fledging success was 32.5 percent. There were two peaks of egg-laying in both seasons. They were: May 1-13 and May 29 to June 9 in 1963 and May 4-16 and June 3-16 1n 1964. Egg laying occurred from late April to mid-June in both years and clutch size averaged 4.3 for all nests with complete clutches. Predation was the major cause of nesting failures with 39 nests, 104 eggs, and 17 young being destroyed by predators. One known predator was the eastern wood rat, Neotoma florldana (Ord). On the day of hatching nestlings weighed 6.0 grams, averaged 8.3 mm for tarsus length, and averaged 6.7 mm for culmen length. On the day of fledging they averaged 68.2 grams for weight, 33.0 mm for tarsus length, and 16.4 mm for culmen length.

Rights

Copyright 1964 Gerald D. Lindsey

Comments

Notice: This material may be protected by copyright law (Title 17 U.S. Code).

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