Specific status and behavior of Cymbilaimus sanctaemariae, the Bamboo Antshrike, from southwestern Amazonia
Auk
1983
Journal Article
100
3
645-652
Cymbilaimus sanctaemariae Formicariidae animals birds Bamboo Antshrike single-species study ecology animal behavior taxonomy systematics distributions habitat selection bamboo Guadua plant-animal interactions endemism Reserva Nacional Tambopata Parque Nacional Bahuaja-Sonene plants grasses Poaceae habitat heterogeneity Madre de Dios Bibliography
Cymbilaimus sanctaemariae (Formicariidae), previously considered to be a little known sub-species of Cymbilaimus lineatus, is a separate species. The two species overlap to a considerable extent in respect of their ranges of distribution, but are distinct in plumage, song and habitat. Both are found in the TRZ, where T. Parker (pers. comm.) has made sound recordings of their song, and found that they have different preferences in regard to habitat. C. sanctaemariae is smaller than C. lineatus and its beak is markedly smaller and more slender. The plumages of the two species are rarely similar, but there are common characteristics in both males and females. The most striking characteristic is the bars on the tail. In the males of all varieties of C. lineatus, the white bars are thin and arched and almost meet in the middle of each tail feather. In C. sanctaemariae these bars are short, wide and stubby on both edges of the plumage, so they never meet in the middle; both the females and the males of C. sanctaemariae have a long black crest. The different songs of the two species are evidence consistent with their being separate species. In C. lineatus both sexes have the same song, while in C. sanctaemariae the male has a harmonious and rasping call. C. sanctaemariae appears to be a specialist in bamboo (Guadua sp.) and, like all members of the formicariidae family, is insectivorous. It normally forages in very dense masses of bamboo branches, and lives in the tops of plants 12-15 m high, being exclusively found in this type of habitat. They appear to live in pairs in exclusive territories. C. lineatus forages for insects usually in dense vegetation with creepers at a height of 6-20 m in the undergrowth and sub-canopy of tall tropical forest (40-50 m tall). It appears to be monogamous and is frequently associated with mixed zones of undergrowth and low canopy. C. sanctaemariae appears to be the link between the genera Cymbilaimus and Thamnophilus; it is one of a number of bird species known to be endemic in South America and associated with bamboo.