TY - JOUR
T1 - Improved methods for reducing translocation mortality and obtaining reliable population projections for reintroduction of the New Zealand Rifleman Acanthisitta chloris
AU - Withers, Sarah
AU - Armstrong, Doug
AU - Ward-Smith, Tamsin
AU - Parsons, Stuart
AU - Hauber, Mark E.
N1 - Publisher Copyright:
© 2019 BirdLife International.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Despite many notable successes, the failure rate of animal translocations remains high. Conservation practitioners and reintroduction specialists have emphasised the need for ongoing documentation of translocation attempts, whether successful or not, including detailed methodologies and monitoring approaches. This study reports on the first translocation of the North Island subspecies of New Zealand's smallest bird, the endemic Rifleman Acanthisitta chloris granti. We describe an improved transfer methodology following recommendations arising from a previous translocation of South Island Rifleman Acanthisitta chloris chloris. Key modifications included a reduced capture window, shorter holding times, lack of extended aviary housing, and separation of territorial individuals during holding. Survival from capture to release increased from 52% to 97% using this new methodology. However, only 22% of 83 released birds were found in the reserve the next breeding season, resulting in an initial breeding population of only six males and five females. An integrated Bayesian analysis of three years of subsequent population data, including a population boost from a second translocation, projected a median decrease to 0-5 females over 10 years, but with 95% prediction intervals ranging from 0 to 33. These projections explicitly account for parameter uncertainty, as well as demographic stochasticity, and illustrate the need to do so when making inferences for small reintroduced populations.
AB - Despite many notable successes, the failure rate of animal translocations remains high. Conservation practitioners and reintroduction specialists have emphasised the need for ongoing documentation of translocation attempts, whether successful or not, including detailed methodologies and monitoring approaches. This study reports on the first translocation of the North Island subspecies of New Zealand's smallest bird, the endemic Rifleman Acanthisitta chloris granti. We describe an improved transfer methodology following recommendations arising from a previous translocation of South Island Rifleman Acanthisitta chloris chloris. Key modifications included a reduced capture window, shorter holding times, lack of extended aviary housing, and separation of territorial individuals during holding. Survival from capture to release increased from 52% to 97% using this new methodology. However, only 22% of 83 released birds were found in the reserve the next breeding season, resulting in an initial breeding population of only six males and five females. An integrated Bayesian analysis of three years of subsequent population data, including a population boost from a second translocation, projected a median decrease to 0-5 females over 10 years, but with 95% prediction intervals ranging from 0 to 33. These projections explicitly account for parameter uncertainty, as well as demographic stochasticity, and illustrate the need to do so when making inferences for small reintroduced populations.
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U2 - 10.1017/S0959270918000412
DO - 10.1017/S0959270918000412
M3 - Article
AN - SCOPUS:85064911460
SN - 0959-2709
VL - 29
SP - 542
EP - 557
JO - Bird Conservation International
JF - Bird Conservation International
IS - 4
ER -