Individual study: Translocation as a conservation tool for palila Loxioides bailleui, an endangered Hawaiian honeycreeper, on Mauna Kea, Hawaii
Fancy S.G., Snetsinger T.J. & Jacobi J.D. (1997) Translocation of the palila, an endangered Hawaiian honeycreeper. Pacific Conservation Biology, 3, 39-46
The palila Loxioides bailleui is an endemic Hawaiian honeycreeper restricted to high-elevation sub-alpine woodland on Mauna Kea volcano, Hawaii. It is classified as Endangered. Palila are now absent or occur only in small numbers throughout most of their historic range due to a combination of factors including habitat loss, predation by introduced mammals and disease. The forest occupied by the palila has been severely over-browsed and over-grazed by feral sheep and goats, and invasive grasses suppress regeneration of the palila's main food plant, mamane Sophora chrysophylla. The palila feeds almost exclusively on the unripe seeds of mamane but also the larvae of a moth Cydia spp. that also eats mamane seeds.
In some areas the palila's habitat is regenerating as a result of ungulate control, but the species is considered slow in recolonising its former range where the habitat has recovered, because of strong site fidelity. Therefore, in an attempt to increase the occupied range and hopefully speed a population recovery, translocation of some birds was undertaken in 1993.
In an effort to restore palila habitat, most feral goats and sheep were removed from Mauna Kea in 1982. Subsequently habitat gradually improved in some areas.
In March 1993, 35 wild caught palila (from populations at least 20 km distant) were translocated to Kanakaleonui on the eastern slope of Mauna Kea. They were released in an area where it was considered that the mamane-naio dominated woodland had regenerated sufficiently to support palila and where control of rats Rattus spp. and feral cats Felis catus was ongoing. It was considered highly unlikely that palila would re-colonise this isolated area naturally due to their strong site fidelity.
Approximately half of the translocated birds remained at the release site for 2-6 weeks but then homed back to their capture site. Although many of the palia returned back to their capture site, at least two translocated pairs successfully nested at the release site during their first breeding season, and two other pairs constructed nests. The density of palila at Kanakaleonui in the three years following the translocation (1994-1996) remained higher than that before translocation.
Conclusions: Translocation of adult birds, and perhaps also release of captive-reared juvenile palila, in combination with additional habitat restoration, may be effective in enhancing the recovery of palila. Additional translocations have been undertaken and it is hoped that this and continued management of the mamane-naio woodlands will benefit palila and other native birds in the long-term.
BirdLife International (2005) Species factsheet: Loxioides bailleui. http://www.birdlife.org on 6/10/2005
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