Ecology of nesting waterfowl on Anderson Mesa, in north central Arizona

Abstract

Ducks nesting on seasonal and semi-permanent wetlands near Flagstaff, Arizona were studied during 1978, 1979, and 1980 to determine factors limiting the production of waterfowl. The breeding population was comprised of 12 species of ducks. Pintails (Anas acuta), cinnamon teal (A. cyanoptera), redheads (Aythya americana), and ruddy ducks (Oxyura jamaicensis) made up 72% of the breeding population. Redheads and ruddy ducks were essentially limited to nesting in dense stands of hardstem bulrush (Scirpus acutus) found only in semi-permanent wetlands. Reproductive success (broods/pair) of redheads and ruddy ducks was limited by high nest abandonment. Pintails and cinnamon teal indicated a strong preference for seasonal wetlands. Reproductive success of both species was greater on seasonal wetlands. Cinnamon teal success was limited by intense nest depradation by crows (Corvus brachyrhyncos) and ravens (C. corax). The quality of upland nesting cover was reduced by cattle and may have facilitated corvid predation.