Single-tree selection harvesting is frequently used in the tolerant hardwood forests of North America but relatively little is known about how this silvicultural system affects wildlife, including many avian species. I investigated Rose-breasted Grosbeak (Pheucticus leudovicianus) habitat use, survival, and nestling provisioning behaviour in twelve hardwood stands in Algonquin Provincial Park which had been harvested by single-tree selection 0-5, 16-20, 21-25, and > 50 years previously. Density, pairing success, and the number of fledglings per successful nest were all significantly lower in the > 50 years post-harvest stands than in at least one other post-harvest treatment. Density and pairing success were significantly higher in the 16-20 year post-harvest stands than in other treatments. Neither nest nor fledgling survival differed significantly among post-harvest treatments, but all stands were population sinks except those cut 16-20 years previously. Nests that were initiated earlier in the season and built in areas with higher basal area were more likely to survive, whereas fledgling survival increased with days since fledging. Nest sites had higher cover from regenerative growth, saplings, and understory, and lower basal area than random locations. During their first week out of the nest, fledglings used locations with significantly higher cover from regenerative growth, saplings, small shrubs, and raspberry and elderberry bushes than were present at random locations. Habitat characteristics at nest and fledgling locations were significantly different, and estimates of nest and fledgling survival were not correlated among harvested stands. Nests attended by after-second-year (ASY) males were initiated significantly earlier, and territory density and productivity were significantly higher for ASY males than for second-year (SY) males. Nestling provisioning rates, male contribution to nestling provisioning and nest attendance, and mean nestling weights at the time of fledging were also significantly higher at nests attended by ASY males than at nests with SY males. This study found that single-tree selection did not have significant negative effects on Rose-breasted Grosbeaks breeding in a predominantly forested landscape, but like many other species of birds, experienced breeders were more successful than less experienced breeders were.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/31917 |
| Date | 11 January 2012 |
| Creators | Richmond, Sonya |
| Contributors | Malcolm, Jay R. |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
Page generated in 0.002 seconds