Establishment of a Self-Sustaining Population of a Long-Lived, Slow-Breeding Gecko Species (Diplodactylidae: Hoplodactylus duvaucelii) Evident 15 Years after Translocation

Duvaucel's Geckos (Hoplodactylus duvaucelii) are large-bodied, long-lived, and slow-breeding geckos endemic to New Zealand. Translocation is considered an important tool for conservation of this species. The first translocation of these geckos occurred in 1998 when 40 geckos were released on a pest-free island. Despite multiple survey efforts within the decade after release, captures were too sparse to determine whether the population had successfully established. We revisited the population to investigate establishment over a longer time period (11-15 yr post release). We utilized a recently developed outcome assessment framework that assesses a translocation's success as a progression through four, time-bound 'Stages.' We recaptured 12 founder animals and all were larger than at release (Stage 1). Recruitment was evident (Stage 2) with 91.7% of all geckos captured between 2009 and 2013 being island-born. Mark-recapture results from 144 individuals estimated that 245 geckos (95% confidence interval: 179-336) were present in the population by February 2013, an approximately 6-fold increase in number since 1998 (Stage 3). Population viability analysis indicated the population has become self-sustaining, with an average population increase rate of 6.35-10.14% per year and a negligible probability of extinction within 50 yr (Stage 4). In this case, a 10-15 yr time period appeared to be a sufficient time frame for identification of translocation success by both traditional and time-bound criteria. Fulfilment of each time-bound indicator of short-term success therefore appears to have been a reliable predictor of ultimate translocation success in this long-lived, slow-breeding lizard species.