Nest predation of Abert's Towhees by coachwhips and roadrunners

Abstract

Predation by snakes has been implicated as a major cause of high nesting mortality in many passerine birds (e.g., Willis 1972, Best 1978, Nolan 1978), but predation is rarely observed (e.g., Snow 1962, Lill 1974). Snakes and other predators typically consume the entire contents of a nest during one visit (e.g., Nolan 1978). Nestling starvation caused by sibling competition for food is frequently invoked to explain partial loss of broods (e.g., Ricklefs 1965, Howe 1978). While conducting a study of Abert's Towhees (Pipilo aberti) in the lower Colorado River valley 9.7 km north of Ehrenberg, Arizona from March to July 1980, I witnessed two instances of nest predation and one predation attempt. My observations suggest that, in some cases, predation is an alternative explanation for partial loss of broods.

Citation

Finch, Deborah M. 1981. Nest predation of Abert's Towhees by coachwhips and roadrunners. The Condor. 83(4): 389.