No abstract

A new method of measuring reproductive success was used to test Van Horne's (1983) contention that reliance on population density as a measure of habitat quality can produce misleading results. None of the three emberizine sparrows in this study showed a clear correlation between high territory density and high reproductive success. Grasshopper Sparrows (Ammodramus savannarum) were most successful in medium-density plots, and did poorly when territory density was low. Savannah Sparrows (Passerculus sandwichensis) were significantly more successful at low density, and were least successful at high density. Vesper Sparrows (Pooecetes gramineus) were the only species whose reproductive success was unaffected by territory density and, thus, for which density would have been a reasonable measure of habitat quality. These results lend support to Van Horne's thesis that the singular use of density may be a poor indicator of habitat quality and that additional factors should be considered.

No abstract

Wells et al.Boreal Forest Conservation Issues and Opportunities for Indigenous government land conservation and stewardship activities, and should develop new protected area co-management models with Indigenous governments. Governments should also be strongly advocating for raising the global Convention on Biological Diversity protected area goal to at least 30% by 2030.