Habitat selection and reproductive success of Lewis's Woodpecker (Melanerpes lewis) at its northern limit.

PLoS One. 2012;7(9):e44346. doi: 10.1371/journal.pone.0044346. Epub 2012 Sep 18. Zhu X1, Srivastava DS, Smith JN, Martin K. Author information 1 Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada. Abstract Lewis's Woodpecker (Melanerpes lewis) has experienced population declines in both Canada and the United States and in 2010 was assigned a national listing of threatened in Canada. We conducted a two-year study (2004-2005) of this species at its northern range limit, the South Okanagan Valley in British Columbia, Canada. Our main objective was to determine whether the habitat features that influenced nest-site selection also predicted nest success, or whether other factors (e.g. cavity dimensions, clutch initiation date or time of season) were more important. Nest tree decay class, density of suitable cavities and total basal area of large trees were the best predictors of nest-site selection, but these factors were unrelated to nesting success. Estimates of demographic parameters (mean ± SE) included daily nest survival rate (0.988±0.003, years combined), nest success (0.52±0.08), clutch size (5.00±0.14 eggs), female fledglings per successful nest (1.31±0.11), and annual productivity (0.68±0.12 female fledglings per nest per year). Although higher nest survival was associated with both early and late initiated clutches, early-initiated clutches allowed birds to gain the highest annual productivity as early clutches were larger. Nests in deep cavities with small entrances experienced lower predation risk especially during the peak period of nest predation. We concluded that nest-site selection can be predicted by a number of easily measured habitat variables, whereas nest success depended on complicated ecological interactions among nest predators, breeding behaviors, and cavity features. Thus, habitat-based conservation strategies should also consider ecological factors that may not be well predicted by habitat. PMID: 23028525 PMCID: PMC3445559 DOI: 10.1371/journal.pone.0044346 [Indexed for MEDLINE] Free PMC Article Share on FacebookShare on TwitterShare on Google+ Images from this publication.See all images (4)Free text Figure 1Figure 2Figure 3Figure 4 Publication type, MeSH terms