Notes on Avian Bamboo Specialists in Southwestern Amazonian Brazil

Abstract

A number of bird species in southwestern Amazonia are associated with stands of bamboo. We studied the birds in bamboo in two regions, eastern Rondonia near the Rio where a single small patch was located, and near Alta Floresta, in northern Mato Grosso, where several extensive bamboo stands were explored. We found a moderately large bamboo avifauna at each site, with eight species in Rondonia and ten at Alta Floresta. In species accounts, we discuss the significance of these records and provide notes on the ecology and behavior of these bamboo species. For most of these species, these records represented significant range extensions. Four species were recorded in Brazil for the first time. We also located a population of Poecilotriccus tricolor, previously known from a unique type, in Rondonia. We determined that it should be treated as a weakly differentiated subspecies of Poecilotriccus capitalis. Resumo. VaYias espe*cies de aves no sudoeste da Amazonia associam-se com bambuzais. Investigamos as aves de bambu em duas regioes: na regiao leste de Rondonia, perto ao no Jiparana* onde encontramos um pequeno bambuzal, perto de Alta Floresta, no norte de Mato Grosso, onde emploramos v£rios bambuzias. Encontramos uma avifauna bastante diversa associada com bambus, composta de oito especies em Rondonia, de dez em Atla Floresta. No relato de espe*cies, discutimos a importancia destes registros, fornecemos imforma9oes sobre a ecologia o comportamento destas especies. Para a maioria destas espe*cies, estes registros representam um aumento significante na drea de distribuic.ao. Quatro especies foram registradas no Brasil pela primeira vez. Tambe*m, localizamos uma populac^o de Poecilotriccus tricolor, antes conhecido s6mente do holotipo, em Rondonia. Determinamos que esta forma e uma subespe*cie pouco differenciada de Poecilotriccus capitalis. During ornithological surveys in Rondonia and Mato Grosso, Brazil, in 1986 and 1989, we made observations on birds inhabiting tall, dense thickets of spiny bamboo (Guadua spp.) within both disturbed and undisturbed rainforests. Large species of bamboo occur patchily in southern Amazonia, primarily in floodplain forests along riverbanks or on natural landslides in hilly terrain. Guadua bamboos quickly invade clearings, and some bamboo-dwelling bird species may be spreading because of deforestation in SW Amazonia (Parker and Remsen 1987). On 6 and 11 November 1986, during an avifaunal survey in Rondonia conducted by the Field Museum of Natural History (FMNH) and the Museu de Zoologia, Universidade de Sao Paulo (MZUSP), Stotz and Fitzpatrick, together with T. S. Schulenberg, D. E. Willard, S. M. Lanyon and A. T. Peterson surveyed an isolated bamboo area of ca. 4 ha in partly disturbed terra firme forest at the edge of a recently planted corn field, along the road from Jam to Mac.adinho, ca. 40 km W of Cachoeira NazarS (9°44'S, 61°53'W), Rio Jiparana This was the only substantial