Individual study: Breeding success of translocated saddleback Philesturnus carunculatus reintroduced to Breaksea and Ulva Islands (Southland) and Motuara Island (Marlborough), New Zealand
Hooson S. & Jamieson I.G. (2004) Variation in breeding success among reintroduced island populations of South Island saddlebacks Philesturnus carunculatus carunculatus. Ibis, 146, 417-426
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
A site comparison study on three islands offshore from South Island, New Zealand, in April-June 2001 (Hooson & Jamieson 2004), found that the nesting success of translocated saddlebacks Philesturnus carunculatus declined with increasing difference in latitude from the source population. All birds originally came from Big South Cape island, being translocated to the study islands and others when rats invaded Big South Cape in 1964. Birds on Ulva Island (60 km north of Big South Cape) had 73% nesting success (11 pairs), compared with 32% (16 pairs) for Breaksea Island (190 km north) and 19% success (14 pairs) for Motuara Island (810 km north). Success was calculated using the Mayfield method and differences were largely due to higher egg fertility and hatching success. The authors note that differences in habitat (due to latitude) were unlikely to be the only reason for varying reproductive success, as Breaksea, Ulva and Big South Cape are all similar in habitat, but Breaksea had significantly lower reproductive success.