Hawai'i conservation alliance

2010 Runner Up Best Student Oral Presentation

Predictors of translocation success to a mainland reserve: New Zealand South Island saddlebacks reintroduced to Orokonui Ecosanctuary

Bryce Masuda, Ian Jamieson
University of Otago, Department of Zoology, New Zealand

Avian translocations to offshore islands are a commonly used conservation tool in New Zealand, and factors influencing their success have been examined since the 1960s. In contrast, translocations to mainland reserves are a recent and increasingly popular management strategy due to advances in predator eradication techniques and predator-resistant fence technology, a growing interest in community-led initiatives, and a desire to make rare species accessible to the public. However, mainland reserves present their own suite of problems, particularly the ease of which birds can disperse from the release site. We monitored a translocated population of South Island saddlebacks (Philesturnus carunculatus carunculatus) for one year after release to understand the role of individual demographic factors such as age, sex, and previous pairing experience on successful establishment. In 2009, 40 birds were translocated to Orokonui Ecosanctuary, a community-based predator-resistant fenced mainland reserve. Equal sex ratios of fledglings (25%) and adults (75%) were released. Resightings declined over the winter, partly due to birds dispersing from the ecosanctuary. At the start of the breeding season, 35% of the original founders were observed within the sanctuary, including 60% of the released fledglings and 27% of the released adults. Fledglings may be better translocation candidates to mainland sanctuaries as they appear to settle close to the release site. Translocations to mainland reserves are an effective conservation tool, particularly in areas where small, predator-free offshore islands are limited, such as Hawai‘i. However, we suggest demographic factors such as age should be considered to maximize translocation success.