Adjacent nesting and egg stealing between males in the Greater rhea, Rhea americana

FERNANDEZ, GUSTAVO J.; REBOREDA, JUAN C.

JOURNAL OF AVIAN BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 1995 vol. 26 p. 321 - 324

0908-8857

In a three year field study on a population of 350 greater Rheas Rhea americana we followed the fates of 138 nests. In four of these nests we observed that, instead of one, there were two males sitting. These males were less than one meter apart during the incubation period, they stole eggs from each other. There were no signs of aggression between them. The total number of eggs in these adjacent or double nests was similar to that in single nests: Each double nest began as a single nest but during the incubation, a second male sat beside the first male and started stealing eggs. We discuss possible functional and mechanistic explanations of this apparently misdirected behaviour.