Estimation of Avian Population Sizes and Species Richness across a Boreal Landscape in Alaska

Publication Type:Journal Article
Year of Publication:2009
Authors:Handel, CM, Swanson, SA, Nigro, DA, Matsuoka, SM
Journal:The Wilson Journal of Ornithology
Volume:121
Issue:3
Date Published:2009
ISBN Number:15594491
Keywords:Canada, Corvidae, Dendroica, Dendroica coronata, Emberizidae, Fringillidae, Garrulus, Garrulus glandarius, Junco, Junco hyemalis, Loxia, Loxia curvirostra, Loxia leucoptera, Pachyramphus, Pachyramphus polychopterus, Parulidae, Parus hudsonicus, Perisoreus, Perisoreus canadensis, Poecile, Poecile hudsonica, Poecile hudsonicus, Setophaga, Setophaga coronata
Abstract:We studied the distribution of birds breeding within five ecological landforms in Yukon-Charley Rivers National Preserve, a 10,194-km² roadless conservation unit on the Alaska-Canada border in the boreal forest zone. Passerines dominated the avifauna numerically, comprising 97% of individuals surveyed but less than half of the 115 species recorded in the Preserve. We used distance-sampling and discrete-removal models to estimate detection probabilities, densities, and population sizes across the Preserve for 23 species of migrant passerines and five species of resident passerines. Yellow-rumped Warblers (Dendroica coronata) and Dark-eyed Juncos (Junco hyemalis) were the most abundant species, together accounting for 41% of the migrant passerine populations estimated. White-winged Crossbills (Loxia leucoptera), Boreal Chickadees (Poecile hudsonica), and Gray Jays (Perisoreus canadensis) were the most abundant residents. Species richness was greatest in the Floodplain/Terrace landform flanking the Yukon River but densities were highest in the Subalpine landform. Species composition was related to past glacial history and current physiography of the region and differed notably from other areas of the northwestern boreal forest. Point-transect surveys, augmented with auxiliary observations, were well suited to sampling the largely passerine avifauna across this rugged landscape and could be used across the boreal forest region to monitor changes in northern bird distribution and abundance.
URL:http://www.jstor.org/stable/20616941
Short Title:The Wilson Journal of Ornithology
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