Comparison of survey methods for detection of the elusive Western Whipbird psophodes nigrogularis with notes on its distribution

Reliable survey methods for detecting the geographic extent of occurrence and population size are needed to inform conservation management of individual species. Commonly used survey methods for monitoring bird populations include transects, point counts, spot maps, area searches, nest searches, and mist netting (mark and recapture). These methods work best on species that are moderately abundant to abundant, and are not particularly effective for rare or elusive species that are usually of the most concern to conservation management. An established approach for monitoring rare and elusive songbird populations is the use of vocalisations, both to assess abundance by identifying individual singers in the field by their songs, using automatic or manual equipment, and to use playback to simulate territory intrusion in order to measure territory defence and presence. The Western Whipbird of southern Australia is elusive and sedentary, and its conservation status varies between the sub-species from Vulnerable to Critically Endangered. Here, we compare two survey methods used to collect distribution data on the Western Whipbird: (1) playback of local Western Whipbird songs; and (2) automated recording stations. The results showed that there was no difference in detectability using the two methods. However, the playback method was less labour intensive than the use of automated recording stations (which required hours of post-collection data analysis). We combined our data with historical data and report that the range of the Western Whipbird has contracted by at least 50% since European settlement 200 years ago.