Differential habitat use by Acadian Nelson's sharp-tailed sparrows: implications for regional conservation
Nelson's Sharp-tailed Sparrows (Ammodramus nelsoni) that breed along the Atlantic coast of North America (Acadian subspecies subvirgatus) are considered saltmarsh specialists. However, these sparrows occasionally use upland habitats, such as hayfields. To evaluate the importance of hayfields as breeding habitat, we studied populations of A. n. subvirgatus in saltmarsh and hayfields in Nova Scotia, Canada, in 2004 and 2005. We monitored relative abundance and breeding phenology at 64 point-count stations (48 in hayfields and 16 in saltmarsh) and used an ordinal (0–5) observational index to quantify reproductive activity. A. n. subvirgatus showed more evidence of reproductive activity in saltmarsh (44% of point-count stations) than hayfields (28%; P= 0.07). However, there was no difference in either mean reproductive activity (saltmarsh = 0.83, hayfields = 0.53; P= 0.69) or mean relative abundance (saltmarsh = 0.27, hayfields = 0.26; P= 0.93). Although A. n. subvirgatus apparently breeds primarily in saltmarsh, hayfields appear to be an alternative breeding habitat. Use of hayfield habitat by A. n. subvirgtus, however, seems to vary between southern Maine and eastern Canada, suggesting that management plans will require approaches uniquely tailored to specific regions.
Ammodramus nelsoni subvirgatus;
Document Type: Research Article
Atlantic Bird Observatory, Biology Department, Acadia University, Wolfville, NS, Canada B4P 2R6
Canadian Wildlife Service, Atlantic Region, P.O. Box 6227, Sackville, NB, Canada E4L 1G6
Nova Scotia Department of Natural Resources, Wildlife Division, 136 Exhibition St., Kentville, NS, Canada B4N 4E5
Publication date: March 1, 2007