Effects of selection cutting and landscape-scale harvesting on the reproductive success of two neotropical migrant bird species

We measured the effects of forest harvesting at two spatial scales on the productivity of two Neotropical migrant bird species, the Black-throated Blue Warbler (Dendroica caerulescens) and the Ovenbird (Seiurus aurocapillus). We selected two forest landscapes representing extremes in harvesting intensity for northwestern New Brunswick, Canada. Within each landscape, we selected study plots located either in recent (<5 years) selection-cut stands (30% removal every 20 years) or in stands that were lightly harvested at least 30 year ago. Black-throated Blue Warblers reached higher densities in selection cuts, but their reproductive performance (pairing and fledging success) did not suffer significantly between stand types (uncut vs. selection cut) or between landscape types (intensity vs. moderately harvested). In 1998, nonetheless, 61% of the estimated number of fledglings produced in our plots were born in selection cuts. In contrast, this proportion was only 23% for Ovenbirds in 1998 and 1999 combined. Ovenbirds had lower densities, and their reproductive performance was significantly lower in selection cuts than in uncut plots. These results indicate that the effects of selection cutting on demography are species-specific and that Ovenbird persistence in selection cuts may be compromised unless the intensity or frequency of cutting is decreased.