Meeting Abstract

64.6  Sunday, Jan. 6  Nest success, fledgling survival, and habitat selection of Hooded Warblers (Wilsonia citrina) in partially harvested forest fragments. ENG, ML*; BURKE, DM; STUTCHBURY, BJS; Simon Fraser Univ.; Ontario Ministry of Natural Resources; York Univ. margaret_eng@sfu.ca

Assessment of population productivity and breeding habitat quality for Neotropical migrant birds often is based on adult density and nest success, and does not consider the post-fledging period. We studied the effects of partial harvest on survival and habitat selection for both the nest and fledgling stages of Hooded Warblers (Wilsonia citrina) in southern Ontario forest fragments over the 2005 and 2006 breeding seasons. We compared single-tree selection and heavy cut sites to reference sites that had not been harvested in over 20 years. Young were tracked for up to three weeks post-fledging using radiotelemetry. Predation was the main cause of mortality for both nestlings and fledglings. The apparent quality of each harvest treatment varied depending on the demographic parameter in question. Density of adult males was highest in selection sites and lowest in reference sites. Method of harvest had no influence on nest success (20%), but fledgling survival did differ significantly among treatments (37% in selection, 85% in heavy cut, and 51% in reference sites). Annual recruitment of juveniles was highest in heavy cut sites and lowest in selection sites, and was below population replacement levels in all treatments. We also measured habitat selection, which differed between nesting adults and fledglings. These results suggest that accurate assessment of population productivity and habitat quality requires knowledge of the fledgling stage, in addition to density and nest success measures.