Factors Influencing the Detectability of Forest Owls in Southeastern Alaska

The condor

Michelle L. Kissling¹ 

关键词: Barred Owl;    detection probability;    Northern Saw-whet Owl;    occupancy;    point count;    Western Screech-Owl;   

DOI  :  10.1525/cond.2010.090217

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. Patch-occupancy models offer a realistic approach to monitoring populations of nocturnal owls. However, because most owls are relatively rare, increasing the probability of detecting an owl at an occupied site will make estimates of occupancy more precise. We investigated the influence of temporal, biological, and environmental factors on rates of detection of forest owls in southeastern Alaska, 2005–2006. Following MacKenzie et al. (2006), we modeled probabilities of detection of the Northern Saw-whet Owl (Aegolius acadicus), Western Screech-Owl (Megascops kennicottii), and Barred Owl (Strix varia). We conducted 479 point counts over 100 days and detected owls 147 times. Sound broadcast increased detections 21–86% over silent surveys. During peak detection (9 April–8 May), probabilities (SE) of detection were 0.39 (0.13) for the Western Screech, 0.44 (0.16) for the Saw-whet, and 0.54 (0.25) for the Barred. For the Barred and Saw-whet, estimated occupancy probabilities (ψ) were constant (i.e., d...

【 授权许可】

CC BY