LIFE HISTORY OF THE BRIGHT‐RUMPED ATTILA ATTZLA SPADZCEUS

Abstract

SUMMARYAn adaptable and highly variable species, the Bright‐rumped Attila ranges across the whole breadth of tropical America and from sea level up to 6,000 or 7,000 feet. It inhabits not only rain forests and deciduous woodland but often enters plantations and clearings with scattered trees. It is usually seen alone, high in the trees.Its diet includes insects, small lizards, tiny frogs, fruits, and arillate seeds. Sometimes it catches small creatures from pasture grass or low weeds in plantations. Occasionally it forages with army ants.Both sexes deliver clear, melodious, far‐carrying songs or calls, in Costa Rica chiefly from February to April.A nest found in the Caribbean lowlands of Costa Rica was a bulky open cup, situated 32 inches above the ground on a little shelf in the deep embayment between two high plank buttresses of a great tree at the edge of a cacao plantation. In 1967 this nest held four nestlings that flew on 24 April. A new nest built in the very same site in the following year contained four newly laid eggs on 13 March. They resembled the eggs of certain American flycatchers more than those of other cotingas.Only the female incubated. During an all‐day watch, her sessions ranged from 63 to 111 minutes, her recesses from 13 to 60 minutes, and she covered her eggs for 67% of the time. When she returned to her nest she was escorted closely by her mate. While sitting, she often sang a long‐drawn, subdued nest song, or in a louder voice answered her mate with a song similar to his. The incubation period was no less than 18 days.Newly hatched nestlings had flesh‐coloured skin shaded by dark grey down that was abundant for a passerine. The interior of the mouth was bright orange‐yellow. Even before they were feathered, these nestlings gave weaker‐voiced imitations of their parents' calls or songs, and soon they could reproduce much of the adults' repertoire. The nestling period was about 18 days.Only the female brooded the nestlings, but the two parents took about equal parts feeding them, chiefly with small lizards, tiny frogs, and a few insects, brought one at a time in the parents' bills.The parents defended the territory around their nest, vigorously attacking intruders of their own species.