Nesting among slash; the demographic and behavioural response of the ovenbird (Seiurus aurocapilla) to single-tree selection in a mature continuous hardwood landscape.

摘要

Ovenbird (Seiurus aurocapilla) demography, nest-site selection, and nesting behaviours were compared among unharvested forest stands and stands at three stages of recovery following single-tree selection in a continuously forested landscape in Algonquin Provincial Park, Ontario. No differences were detected in daily nesting success, finite rates of increase or in nesting behaviour among treatments. Ovenbirds were increasingly selective for nest-sites with deep leaf litter and basal areas associated with larger trees in recently harvested stands (1-15 years since harvest), as these microhabitat parameters were limited. By 20-25 years after harvest, nest-site and random plot total basal area was the only microhabitat parameter that remained below pre-harvest levels. Based on source-sink modeling, the Algonquin Park landscape was estimated to be a sink during this study. This sink status appeared influenced by small mammal populations responding positively to strong mast production, which may have increased nest predation risk. Future source-sink modeling and behavioural study should include the influence of resource-pulse dynamics, as dramatically high nest predation rates appeared to mask behavioural plasticity and degraded the utility of Algonquin Provincial Park as a potential source for Ovenbird populations.;Key Words: Ovenbird, demography, nesting behaviour, selection silviculture, continuously forested landscape.