Document Type

Thesis - Open Access

Award Date

1982

Degree Name

Master of Science (MS)

Department

Wildlife and Fisheries Science

First Advisor

Lester D. Flake

Abstract

Breeding biology, nest site activities, and habitat use of great blue herons (Ardea herodias) nesting in the Glendale heronry, South Dakota, were investigated in 1980 and 1981. Mean brood size was 3.35 nestlings. The predicted number of feeding trips of adult birds peaked when nestlings were 29 days old. A significant amount of variance in adult feeding trips per hour was accounted for by southerly winds and the time period from 1800-2100 hours. The variables that were not significantly related to the number of feeding trips were temperature, wind speed, wind directions other than south, cloud cover, and the 4 time periods occurring from 0600-1800 hours. Nest attentiveness of adult birds declined with increasing nestling age, with feeding the predominant nest activity of adults once nestlings reached 5-6 weeks of age. Standing at the nest, standing on branches, and gular fluttering increased as nestlings matured, while the inactive behavior and not visible categories decreased. Gular fluttering by nestlings and ambient temperature were significantly correlated. Important feeding habitats of adult herons included the James River and its inlets, streams, intermittent streams, and pastures. Forty-eight of 65 radiolocations occurred on the James River and its inlets. Unmarked herons travelled average and maximum distances of 3.15 and 24.40 km, respectively. Foraging herons occurred at a rate of 2.33 birds/km of Timber Creek and 3.56 birds/km of the James River. Departure directions of herons from the colony differed significantly during the 2 years of study. A significant amount of departure clumping in the same flight directions occurred, although data collected during the study did not allow the conclusion that the herons were following each other to feeding sites.

Library of Congress Subject Headings

Birds -- South Dakota -- James River Valley -- Habitat
Birds -- South Dakota -- James River Valley -- Ecology
Birds -- South Dakota -- James River Valley -- Eggs and nests
James River Valley (S.D.)

Description

Includes bibliographies

Format

application/pdf

Number of Pages

65

Publisher

South Dakota State University

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