Publication Date

1968

Document Type

Dissertation/Thesis

First Advisor

Southern, William E.||Mathers, Carrol K.

Degree Name

M.S. (Master of Science)

Department

Department of Biological Sciences

LCSH

Crows

Abstract

Evening entrance and morning departure behavior was observed at six crow roosts In DeKalb County, Illinois during the winter of t967-68. About 2,000 crows were observed at all of the sites. Crows apparently have a preference for coniferous groves and deciduous woodlands along creek bottoms for roost sites. After departure froe the roost, the birds usually flew northward toward areas of relatively level farmlands. Intact flocks often flew to a field about 0.5 mile from the roost, where they landed and then later dispersed as smaller groups to areas farther from the roost. The sequence of events associated with pre-roost flocking are: (1) gathering of crows in a secondary roost, usually a cornfield, near the final roost; (2) several short flights near the ground which gradually bring the birds closer to the roost; (3) somewhat random flights around the roost by portions or all of the flock; and, (4) entrance into the roost. The crows departed from, and returned to the roost in direct relation to sunrise and sunset times. Departure and return times did not vary significantly when compared with variations in temperature, wind velocity, and cloud cover.

Comments

Includes bibliographical references.

Extent

vii, 49 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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