Food Selection and Feather Molt by Nonbreeding American Green-Winged Teal in Texas Playas

Abstract

We examined whether intensity of feather molt influenced food selection of nonbreeding American green-winged teal (Anas crceea carolincusis) in the Southern High Plains of Texas from autumn to early winter 1994 (n = 104) and 1995 (n = 85). Invertebrates comprised 8-31% and seeds 69-92% of the foods consumed by teal. All age-sex cohorts of teal consmmed invertebrates in greater proportion than available and consumed seeds less than expected (P ≤ 0.01). Feather molt intensity (% sheathed feathers) was greater during wet (11.64 ± 0.17% in 1995: x ± SE) than dry (3.61 ± 0.14% in 1994) years (P < 0.001). Invertebrate consumption increased as feather molt intensity increased for adult males and juvenile females (P < 0.001). Because teal selected invertebrates over seeds and molt intensity was greater when invertebrates were more abundant natural foods, especially invertebrates, may be an important proximate factor related to feather molt intensity and nutrient-reserve acquisition of nonbreeding green-winged teal in the Southern High Plains. Wetland management for nonbreeding waterfowl should incorporate strategies for production of invertebrates and seeds.