Using occupancy estimates to fine-tune conservation concerns

Abstract

Our study (Sberze et al., 2010) combined three personal contributions: a professor's (M. C.-H.) experience in neotropical ornithology, a post-doc's (G. F.) practice with occupancy estimation, and a graduate student's (M. S.) interest in nocturnal birds. The work was developed in the Biological Dynamics of Forest Fragments Project (BDFFP), a 30-year landscape manipulation experiment focused on biological change in artificially isolated forest patches created by forest clearing in the early 1980s (Laurance et al., 2002). Circumstances beyond control of the BDFFP led to gradual abandonment of cleared land and subsequent growth of c. 30 km2 of secondary forest (SF) surrounded by old growth (OG) and embedding the experimental patches. Our occupancy study of nocturnal birds was at once an effort to take advantage of unplanned secondary growth (as accurately pointed out in Sekercioglu's commentary) and a contribution to the ongoing debate about the conservation value of SF (Laurance & Wright, 2009). We are grateful to the editors of Animal Conservation for featuring our paper and to Ken Feeley, Çagan Sekercioglu and Daisy Dent for their kind and insightful commentaries. We aim this reply at clarifying some of our methodological choices and identifying two avenues for future progress.