Estimating the Abundance of Nesting Rusty Blackbirds in Relation to Wetland Habitats in Alaska

The condor

Steven M. Matsuoka¹ 

关键词: Alaska;    boreal wetlands;    double sampling;    Euphagus carolinus;    habitat selection;    nesting abundance;    Rusty Blackbird;   

DOI  :  10.1525/cond.2010.100148

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. We used double sampling to estimate densities of Rusty Blackbird (Euphagus carolinus) nests among boreal wetlands in Anchorage and Tanana Flats, Alaska, 2007–2008. We also assessed habitat selection by examining the number and location of nests relative to the availability of various wetland types. We rapidly surveyed 78 sample units for adult Rusty Blackbirds and intensively searched for nests in a subset of 55 units to determine actual numbers of nests. Rapid surveys detected 97% of the 75 nests when we restricted counts to pairs and lone females. They overestimated nest numbers by 17% when we included in the counts lone males, which sometimes made long flights within and between sample units. Nest densities in sampled wetlands averaged 2.2 and 3.4 nests km 2 in Anchorage and Tanana Flats, respectively, surprisingly similar despite wetlands being rare in Anchorage. An abundance of wetlands made identifying important breeding habitats difficult on the Tanana Flats, where blackbirds used most we...

【 授权许可】

CC BY