Notes on the Life History of the Pileated Flycatcher

Abstract

When a person has learned the calls of the Pi!eated Flycatcher (Aechmolophus mexicanus), by exercising much patience and vigilance in the usually thick understory of its habitat, he will be rewarded by the observing of one of the rarest of Mexican birds. This flycatcher is a small drab bird about five inches in length, its tail contributing about half its total length. The underparts are very pale yellow and the wing coverts have two white bars. A long pointed crest, with the longer feathers lanceolate, and the jerky motion of the tail are the distinctive field recognition marks. The feathers of the crest may be held fairly flat or more often fully elevated. Male and female are alike in plumage. The range of the Pileated Flycatcher appears to be restricted to the central plateau section of Mexico from Michoacan to Oaxaca and from Guerrero to Morelos. I have found it only in Morelos and Oaxaca at elevations of from 4500 feet to 6000 feet above sea level. It appears to be resident and to breed wherever it is found. (A. R. Phillips, MS, obtained two specimens in Cafion de Lobos on January 24, 1962, indicating a permanent occurrence in this area of Morelos.) This flycatcher inhabits the thick understory of semiarid barrancas and seems to prefer second-growth woodlands and thorn thickets. The mated pairs are solitary and usually forage in the broken shade of the densest portions of the thickets where they dart about catching insects low in the bushes and snapping their bills like wood pewees. The first known example of this species, which eventually was named as the type specimen, was collected by Austin P. Smith on April 9, 1908, with the locality noted as simply Cuernavaca, Mexico.' It was originally identified as Myiochanes richardsonii and was labeled as that form. For thirty additional years, this specimen remained unrecognized until Zimmer discovered it in a tray of Emipidonax traillii at the American Museum of Natural History in New York. After much speculation and study, Zimmer (Auk, 55, 1938:663-665) described this bird as a new genus and species. From 1938 until the publication of part II of the Mexican check-list in 1957 (Pac. Coast Avif. No. 33), apparently some twenty additional specimens were collected from the central plateau section of Mexico from Michoacan to Oaxaca. In 1957, Ernest P. Edwards (Pac. Discovery, 10, no. 4, 1957:24-25) reported the first discovery of the nest of this bird from Caiion de Lobos in Morelos. My studies in Mexico began in 1958 and continued through 1962, during which time I had the opportunity to observe much of the nesting habits of this species.