Adult Red-headed Woodpecker Interaction with Bullsnake after Arboreal Nest Depredation

Authors

• Brittney J. Yohannes, University of MinnesotaFollow
• James L. Howitz, University of Minnesota

Date of this Version

6-2017

Document Type

Article

Citation

The Prairie Naturalist 49:23–25; 2017

Comments

Published by the Great Plains Natural Science Society. Used by permission.

Abstract

Nest success rates often are higher among cavity-nesting birds than those that nest in open cups or on the ground. Among cavity-nesting birds, woodpeckers have some of the highest rates of nest success. A review of woodpecker nesting ecology across species documented nest success ranging from 0.42 to 1.00 with a median of 0.80 (n = 84 populations), and that predation was low, ranging from 0.00 to 0.35 with a median of 0.13 (n = 33 populations). The constrained opening to a cavity nest limits predation to relatively small animals or those able to break open cavity walls. Snakes can readily enter cavities, and predation by various snake species has been observed or assumed a significant cause of egg and nestling mortality for red-headed woodpeckers (Melanerpes erythrocephalus).

The bullsnake (Pituophis catenifer sayi), a subspecies of the gopher snake (Pituophis catenifer), is found throughout the Great Plains region of North America, parts of the Midwest, and northeastern Mexico. Gopher snakes typically eat terrestrial and subterranean mammals, but a study of 2,600 preserved specimens demonstrated that 11.9% of ingested prey were bird eggs, 8.1% were birds, and 0.7% were either nestlings or bird eggs, with frequencies regionally greater in the Great Plains. In captivity, bullsnakes have been shown to develop an exclusive appetite for bird eggs, preferring eggs over live rodents and nestling birds.