Is bigger always better? Influence of patch attributes on breeding activity of birds in box-gum grassy woodland restoration plantings

Abstract

Restoration plantings are an increasingly common management technique to address habitat loss in agricultural landscapes. Native fauna, including birds, may readily occupy planted areas of vegetation. However, unless restoration plantings support breeding populations, their effectiveness as a conservation strategy may be limited. We assessed breeding activity of birds in box-gum grassy woodland restoration plantings in the South-west Slopes bioregion of New South Wales, Australia. We compared breeding activity in plantings of different size (small and large) and shape (linear and block-shaped) to breeding activity in a set of remnant woodland sites. Contrary to expectations, we found that bird breeding activity was greatest per hectare in small patches. We also found a negative effect of planting age, with younger plantings supporting more breeding activity per hectare. We found no effect of patch type or shape on breeding activity, and that species’ relative abundance was not predictive of their degree of breeding activity. Our results highlight the value of small habitat patches in fragmented agricultural landscapes, and indicate that restoration plantings are as valuable as remnant woodland patches for supporting bird breeding activity. We demonstrate the importance of breeding studies for assessing the conservation value of restoration plantings and other habitat patches for avifauna.