Date: 11/29/18 7:28 pm From: Mike Patterson <celata...> Subject: [obol] McKays Bunting - population status
Since I am probably the source to the 5000 figure (a ball-park guess made without any real basis), I figure I' should probably set this one straight...
From Birds of North America Montgomerie, R. and B. Lyon (2011). McKay's Bunting (Plectrophenax hyperboreus), version 2.0. In The Birds of North America (A. F. Poole, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.199
Breeding populations restricted to Hall and St. Matthew islands (Fig. 3) comprising 326 km2 total land area. Based on counts made from 46 regularly spaced transects (total length 202 km) across both islands from 30 May to 29 Jun 2003 (Matsuoka and Johnson 2008), total breeding population size was estimated at 31,200 birds (95%CI = 27,500 – 35,400). Breeding population density was higher on Hall I. (154 birds/km2) than on St. Matthew I. (93 birds/km2), probably owing to the greater preponderance of tundra and rocky upland habitats (Matsuoka and Johnson 2008). Assuming all these birds were breeding, this translates into breeding densities >5 times the median Snow Bunting densities in Nunavut (see Snow Bunting account), possibly due to the greater availability of nest sites or lower predation pressure (Matsuoka and Johnson 2008).
Adult sex ratio observed on transects in the breeding season was 1.33:1 (male:female, n = 2,011 birds) (Matsuoka and Johnson 2008); possibly male-biased because some females were incubating or brooding and thus not counted.