A new Herpsilochmus antwren (Aves: Thamnophilidae) from northern Amazonian Peru and adjacent ecuador : The role of edaphic heterogeneity of terra firme forest

摘要: -Herpsilochmus gentryi, the Ancient Antwren, is described from northern Amazonian Peru and one locality in southeastern Ecuador. As for several other recently birds, new species was first identified by voice. Herpsilochmus gentryi restricted to two structurally distinct kinds of terrafirme forest, growing on nutrient-poor, podzolic quartzitic soils; its distribution almost entirely edaphically controlled. Morphological vocal comparisons strongly indicate a sister relationship with H. stictocephalus widely disjunct Guianan region. Both are sympatric taxa parallel geographic disjunction sticturus complex. However, degree syntopy regions different. We suggest that more limited overlap dugandi function higher habitat mosaicism resulting Andean orogeny fluvial perturbance than relatively stable uniform shield. common within habitat, but itself naturally rare patchily distributed. Construction road through these ancient fragile habitats near city Iquitos has led dramatic increase destruction over just last 10 years. Integration satellite imagery aerial photographs multidisciplinary ground-truthing soil types, botanical inventories teams University Turku, shown terra firme landscape heterogeneity high Peruvian Amazonia, at least some distinctive habitats, such as those readily mapped. history destiny exemplify how deterministic effects local edaphic conditions phytogeographic and, extension, bird distribution, define an integral role factors conservation initiatives, revealing biogeographic patterns. Received 16 September 1997, accepted 2 February 1998. OVER THE COURSE years field work along Tigre, Corrientes, Pucacuro rivers northwestern Loreto, Peru, we (Alvarez 1994, Alvarez Whitney unpubl. data) documented exceptionally diverse avifauna, including not previously known country. An aspect this recording vocalizations. In listened Alvarez's recordings, mostly unseen canopy birds. Among them, he song undescribed antwren, diagnosing it most closely related (Todd's Antwren) late January 1995, mounted brief expedition up Tigre search Herpsilochmus. This resulted tape-recording 3E-mail: 75213.3314@compuserve.com individuals collection adult males which proved be type forest. Subsequent collections both sexes different age classes Alvarez, tape recordings larger sample us, have significantly augmented our knowledge bird's (even edge Iquitos). addition, David J. Stejskal occurrence Kapawi Ecological Reserve Rio Pastaza short distance into Examination material hand, study pertinent selection museum specimens extensive experience genus throughout wide range, convinces us antwren best species. Its description, discussion intrageneric ecological relationships, follows.