The avian biogeography of an Amazonian headwater: the Upper Ucayali River, Peru

Abstract The Ucayali River is a major tributary of the Amazon, but it narrows considerably toward its headwater at the base of the Andes. This region, the upper Ucayali Valley, is of biological interest for the large number of closely related birds elsewhere separated from each other by major rivers that come into close proximity and potential contact. Between 2006–2011, we conducted the first modern ornithological inventory of the upper Ucayali River and sampled localities in all major avian habitats on either side of the river. We document the continued importance of the Ucayali River as a biogeographic barrier, even at the headwater, but also find that some mixing occurs, both in the form of taxa crossing to the “wrong” bank and in the potential intergradation of distinct forms. We describe the biogeography of birds in the region, characterize the avifaunas of major habitats, and discuss in detail species of particular biogeographical interest.

[1]  R. T. Brumfield.  Inferring the Origins of Lowland Neotropical Birds , 2012 .

[2]  R. T. Brumfield,et al.  The Role of Physical Barriers in the Location of Avian Suture Zones in the Guiana Shield, Northern Amazonia , 2012, The American Naturalist.

[3]  Glenn F. Seeholzer,et al.  Avifauna of the Gran Pajonal and Southern Cerros Del Sira, Peru , 2011 .

[4]  W. Bowerman,et al.  More Records of Sympatry of Black-faced Hawk (Leucopternis melanops) and White-browed Hawk (L. kuhli) in Madre de Dios, Peru , 2011 .

[5]  R. Wiley,et al.  Alfonso Olalla and His Family: The Ornithological Exploration of Amazonian Peru , 2010 .

[6]  D. Stotz,et al.  Birds of Peru: Revised and Updated Edition , 2010 .

[7]  A. Whittaker,et al.  Species limits in antbirds (Aves: Passeriformes: Thamnophilidae): an evaluation of Frederickena unduligera (Undulated Antshrike) based on vocalizations , 2009 .

[8]  L. F. Silveira,et al.  NEW LOCALITIES FOR THE BLACK-FACED HAWK (LEUCOPTERNIS MELANOPS) SOUTH OF THE AMAZON RIVER AND DESCRIPTION OF THE IMMATURE PLUMAGE OF THE WHITE-BROWED HAWK (LEUCOPTERNIS KUHLI) , 2007 .

[9]  R. T. Brumfield,et al.  A NEW SPECIES OF THAMNOPHILUS ANTSHRIKE (AVES: THAMNOPHILIDAE) FROM THE SERRA DO DIVISOR, ACRE, BRAZIL , 2004 .

[10]  J. Bates,et al.  Avian mitochondrial DNA sequence divergence across a headwater stream of the Rio Tapajós, a major Amazonian river , 2004, Journal of Ornithology.

[11]  H. Tuomisto,et al.  The role of ecological knowledge in explaining biogeography and biodiversity in Amazonia , 1997, Biodiversity & Conservation.

[12]  A. Kratter,et al.  Bamboo Specialization by Amazonian Birds 1 , 1997 .

[13]  Ju¨rgen Haffer.  On the river effect in some forest birds of southern Amazonia , 1992 .

[14]  G. Rosenberg.  Habitat Specialization and Foraging Behavior by Birds of Amazonian River Islands in Northeastern Peru , 1990 .

[15]  J. Terborgh,et al.  The Role of Competition in the Distribution of Andean Birds , 1975 .

[16]  J. Haffer.  Speciation in amazonian forest birds. , 1969, Science.

[17]  D. Lathrap.  Aboriginal Occupation and Changes in River Channel on the Central Ucayali, Peru , 1968, American Antiquity.

[18]  A. Wallace.  On the Monkeys of the Amazon , 1854 .

[19]  E C Dickinson,et al.  THE HOWARD AND MOORE COMPLETE CHECKLIST OF THE BIRDS OF THE WORLD. 4 th EDITION VOLUME 2 (2014) , 2003 .

[20]  J. O'neill,et al.  NEW SUBSPECIES OF MYRMOBORUS LEUCOPHRYS (FORMICARIIDAE) AND PHRYGILUS ALAUDINUS (EMBERIZIDAE) FROM THE UPPER HUALLAGA VALLEY, PERU , 1997 .

[21]  M. Bush.  Amazonian speciation: a necessarily complex model , 1994 .

[22]  C. Munn,et al.  Nannopsittaca dachilleae, a New Species of Parrotlet from Eastern Peru , 1991 .

[23]  W. L. Brown,et al.  The birds of South America , 1989 .

[24]  J. Cracraft.  Historical Biogeography and Patterns of Differentiation within the South American Avifauna: Areas of Endemism , 1985 .

[25]  J. Weske.  The distribution of the avifauna in the Apurimac Valley of Peru with respect to environmental gradients, habitat, and related species / , 1972 .

[26]  Oficina Nacional de Evaluación de los Recursos Naturales Onern.  Inventario, evaluación e integración de los recursos naturales de la zona del río Tambo-Gran Pajonal , 1968 .

[27]  J. Zimmer.  Studies of Peruvian birds. No. 55, The hummingbird genera Doryfera, Glaucis, Threnetes, and Phaethornis. American Museum novitates ; no. 1449 , 1950 .