A time budget study of green-winged teal wintering on the Texas High Plains

Date

1982-08

Journal Title

Journal ISSN

Volume Title

Publisher

Texas Tech University

Abstract

The Southern High Plains of Texas contain 20,000-30,000 playa lakes. These ephemeral wetlands are the second-most important wintering habitat for waterfowl in the Central Flyway; in years of adequate rainfall they may support 1 million ducks. However, this area is intensively cultivated, with irrigation demands depleting the Ogallala Aquifer at rates exceeding its recharge. The ground water depletion has prompted farmers to modify playa basins for water storage, in turn reducing littoral zones and their biological productivity. Because green-winged teal (Anas crecca carolinensis) especially utilize playas as winter habitat in the Central Flyway, this study reports their behavior and energy demands on the Southern High Plains.

The behavioral ecology of green-winged teal wintering on the playa lakes of the Southern High Plains of Texas was investigated using diurnal time budget data from September 1981 to March 1982. No differences (P >0.05) in activity patterns occurred between males and females. All activities showed differences (P <0.0001) across 6-week seasons. Aquatic feeding was highest during September-October (23.0%) indicating that green-winged teal supplement a nutritionally incomplete diet of corn during periods of molting and fat deposition. Resting was the primary activity throughout the winter, reaching a peak (66.9%) in the coldest season of December-January.

Presumably, green-winged teal are adapted to arrive on their wintering area in early fall when excess productive energy is available to engage in energy costly activities and to meet the demands of molting and fat deposition prior to winter. There is then a shift to less costly activities (i.e., resting) with the onset of cold weather.

Green-winged teal also exhibited distinctive daily activity cycles. Courtship and locomotion were highest (P <0.0001) during early morning, resting was highest (P <0.001) during late morning and afternoon, and feeding was highest (P <0.001) during late afternoon. The influences of several environmental variables were tested, with ambient temperature showing the most correlations with activities.

Management recommendations for green-winged teal include maintaining winter habitat on playas by, 1) restriction of extensive basin modifications, 2) curtailment of grazing and agricultural activities near edges of playa, 3) encouraging the catchment of irrigation runoff.

Description

Keywords

Green-winged Teals, Playas -- Texas, Ducks -- Texas, Ducks -- Ecology, Time management

Citation