LIFE HISTORY OF THE RUFOUS‐TAILED JACAMAR GALBULA RUFICAUDA IN COSTA RICA

Abstract

Summary.In Costa Rica, the Rufous‐tailed Jacamar inhabits both humid second‐growth and primary rain forest, from sea level up to about 3,000 feet. It subsists upon insects, including many large butterflies and dragonflies as well as numerous glittering beetles, all of which it catches on the wing.The search for nest‐sites begins in the dry month of February; eggs are laid from late March until June; and the latest young fledge in July. Both sexes dig the nest burrow in a roadside bank, side of a gully, or the vertical wall of clay raised up by a great uprooted tree. At this time the male often feeds his mate. Burrows range from about 12 to 16 inches in length, are straight or curve more or less to the right, and dilate at the inner end to form a low, unlined nest chamber. The same burrow may be used in successive years.About ten days elapse between the completion of a burrow and the start of laying. The pure white eggs are deposited at intervals of two or more days. In Costa Rica sets of two or three are laid, but farther north in Guatemala two sets of four were found.The female incubates each night. The male replaces her before sunrise, and throughout the day they change places at intervals of 1 1/2 to 2 hours, sometimes more. The incubation period is 19–23 days.The nestlings hatch with abundant, long, white down. They are prognathous and have well‐developed heel pads. They are very loquacious, calling from an early age and soon delivering beautiful, long trills much like those of the adults. Both parents bring them insects, one at a time; no other food was noticed. The male parent fed feathered nestlings about 2 1/2 times as often as the female. In 25 hours, two nestlings were fed at the average rate of 2·4 times each per hour, but there were great hourly fluctuations. Two young who remained in the nest unusually long finally left spontaneously, without parental urging. The nestling period varies from 20 to 26 days and is longest for late broods.Jacamars wholly neglect the sanitation of their nests. They fail to give threat or distraction displays when a man or a small native mammal approaches their burrow.