Observations on the Purple-throated Fruitcrow in Guyana
Snow, D.W. 1971. Observations on the Purple-throated Fruitcrow in Guyana. Living Bird, 10: 5–17.
This paper is based on a study of the Purple-throated Fruitcrow (Querula purpurata) from January to April 1970, in the foothills of the Kanuku Mountains in southern Guyana, where they live in small communal groups of from 3 to 4 birds, with strong social bonds and an almost complete absence of aggressiveness between members of the group.
The adults feed partly on insects and partly on tree fruits, both usually taken on the wing. The fruits of 4 trees (Didymopanax morototoni, Hirtella sp., Guarea trichiliodes, Lauraceae sp.) were especially important during the period of observation.
We found two nests, one of which was successful. Both nests consisted of open cups made of sticks and were situated in isolated trees. The birds made no attempt to conceal the nest, which they defended vigorously by mobbing intruders at all stages of the nesting cycle.
The clutch in the one successful nest consisted of a single egg. Only the female that laid the egg incubated it, but all 4 members of the group brought food to the young. The incubation period lasted 25 days.
The members of the group fed the nestling almost entirely on insects and regularly brought more food than it could eat. One male did 60% of the feeding and he apparently had no difficulty in increasing his feeding rate as the occasion demanded. The young bird left the nest at the age of 32 or 33 d.
We suggest that the Fruitcrow’s breeding strategy has been an important factor determining its body proportions and its social behavior. The 1-egg clutch cannot be an adaptation to the number of young that the adults can feed. We need more information on other species of Cotingidae before we can discuss thoroughly the very long incubation and fledging periods of this and other members of the family.