Browsing by Autor "Ryan S. Terrill"

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    A new genus and species of tanager (Passeriformes, Thraupidae) from the lower Yungas of western Bolivia and southern Peru
    (2021) Daniel F. Lane; Miguel Ángel Aponte Justiniano; Ryan S. Terrill; Frank E. Rheindt; Luke B. Klicka; Gary Rosenberg; Charlotte Schmitt; Kevin J. Burns
    Abstract We describe a colorful and distinctive new species of tanager from the lower slopes of the Andes of southeastern Peru and western Bolivia. The species was first noted from southeastern Peru in 2000, but little of its natural history was uncovered until the 2011 discovery of a breeding population in deciduous forest in an intermontane valley, the Machariapo valley, in Bolivia. This species appears to be an intratropical migrant, breeding in deciduous forest during the rainy season (November–March) and spending the dry season dispersed along the lower slopes of the Andes, apparently favoring Guadua bamboo-dominated habitats in both seasons. Phylogenetic evidence suggests this tanager is embedded within a clade of thraupids that includes Ramphocelus, Coryphospingus, Loriotus, Tachyphonus, and related genera in the subfamily Tachyphoninae. Within this subfamily, the new species falls in a clade with two monotypic genera, Eucometis penicillata (Gray-headed Tanager) and Trichothraupis melanops (Black-goggled Tanager). There is strong support for a sister relationship between the new tanager and T. melanops, but because all three species in this clade are highly distinctive phenotypically, we propose erecting a new genus and species name for the new tanager.
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    The avian biogeography of an Amazonian headwater: the Upper Ucayali River, Peru
    (Wilson Ornithological Society, 2014) Michael Harvey; Glenn F. Seeholzer; Daniel Pascual Cáceres Apaza; Benjamin M. Winger; José G. Tello; Flor Hernández; Miguel Ángel Aponte Justiniano; Caroline Duffie Judy; Sheila Figueroa Ramírez; Ryan S. Terrill
    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.