Cooperative Breeding at a Nest of Slaty-backed Nightingale-Thrushes (Catharus fuscater)

Abstract

ABSTRACT Our observations on the reproductive habits of the Slaty-backed Nightingale-Thrush (Catharus fuscater) were made at a single nest between 2–12 November 2009 at an elevation of 2,050 m, in the vicinity of the Yanyacu Biological Station and Center of Creative Studies (00o 36′ S, 77o 53′ W), 5 km west of Cosanga (Napo Province, northeastern Ecuador). During the first 3 days following hatching, the only adult which provisioned nestlings was a color-banded female. Beginning with day 4, however, we observed five other individuals bringing food to the nest, including three color-banded males, one unmarked male, and one unmarked individual presumed to be female. The last two birds and one of the banded males were sexed using morphological differences, the remaining banded individuals were sexed molecularly. Most (72%) of provisioning visits to 4–9 day old nestlings were made by the color-banded female which also incubated the eggs. Our observations suggest the existence of a potentially complex cooperati...