Timber harvest and tree size near nests explains variation in nest site occupancy but not productivity in northern goshawks (Accipiter gentilis)

摘要: Abstract Conservation concern for the northern goshawk (Accipiter gentilis) reflects evidence that goshawks may abandon nest sites or suffer from reduced nesting success in response to some forms of timber harvest. However, this is mixed and has yet be reviewed systemically quantitatively. Therefore, we conducted a meta-analysis assess extent which harvest tree size explain variation productivity site occupancy. Goshawk was not significantly explained by presence nearby nor average trees either North America Eurasia when averaged across all studies. Effect sizes differed dramatically among studies effect close zero (Zr = 0.04). together more strongly occupancy territories. Within studies, territories with less relatively larger were, most cases, likely occupied. When estimated separately two continents, averages were moderate, consistent (Zr = 0.23–0.27), significantly > 0. combined Eurasia, (Zr = 0.24) (Zr = 0.25) similar strength both Thus taken together, our results suggest although lack large are associated lower goshawks, pairs near small have indistinguishable farther We found substantial heterogeneity especially within America, surprising given greatly research methods, forest type, management. In conclusion, populations conservation concern, such as A. g. laingi, need protection than they currently receiving. Equally important, better understand effects management on recommend additional designed to: (1) identify spatial temporal occupancy; (2) determine what do where go after