Day-time roost patterns of new and previously translocated North Island Brown Kiwi (Apteryx mantelli)

Abstract

Information on the day-time roost areas of North Island brown kiwi (NIBK) (Apteryx mantelli), particularly post-translocation, is limited. This study aimed to determine the day-time roost areas of newly translocated NIBK and compare these with birds that had established from a translocation in the previous year. Radio telemetry was used to monitor sub-adult NIBK in the first three weeks post-translocation simultaneously with birds released in the previous year. The data from 15 birds (nine translocated in 2014 and six translocated in 2013) were used to calculate the area over which roost sites were distributed. Areas were estimated using Minimum Convex Polygon (MCP, Ha) and 50 percentile kernel density estimation (KDE, Ha). No significant difference in MCP was determined between newly translocated 2014 birds (21.3 Ha, SE 7.92) and those translocated in 2013 (22.85 Ha, SE 10.84) or between KDE50 for 2013 birds (16.30 Ha, SE 7.44) compared with 2014 birds (20.66 Ha, SE 8.29). Within the first three weeks post-translocation, most of the 2014 birds remained within the vicinity of their release site, which may be due to a combination of suitable habitat/roost sites and the ‘anchoring’ effect of previously established 2013 birds. This study provides new information on roost areas of newly translocated NIBK and highlights the importance of post-translocation monitoring.