Survival, movements, and breeding of released Hawaiian geese: an assessment of the reintroduction program

  • Published source details Black J.M., Marshall A.P., Gilburn A., Hoshide H., Medeiros J., Hodges C.N. & Katahira L. (1997) Survival, movements, and breeding of released Hawaiian geese: an assessment of the reintroduction program. Journal of Wildlife Management, 61, 1161-1173.


Hawaiian geese (nene) Branta sandvicensis were reduced to 30 wild and 13 captive individuals in 1949. A large-scale captive-breeding and reintroduction programme was begun. This study reports on the programme’s impact.


Large numbers of Hawaiian geese were bred in captivity and released at one low to mid-elevation site and four high-elevation sites on Hawaii and one high-elevation site on Maui.

All geese were kept in enclosures following release and were either released before fledging, or had their wings clipped to prevent them leaving the enclosure too quickly.

Goose survival and reproduction were monitored after release and their movements recorded using individual colour rings.


Since 1949, 2,150 birds were released but this did not result in a self-sustaining wild population.

Estimated mortality rates ranged from 0-87% annually, although were generally low until droughts in 1973-86, when 1,200 released geese died. Mortality rates were lower in the lowest-altitude release site (at <1,300 m a.s.l.), with only three years between 1976 and 1983 having mortality rates over 15%. In contrast, the few geese released in uplands that survived the droughts did so by migrating away from their release site.

Over the study period there were 515 nests recorded, with 37% raising at least one gosling. Overall there were 473 goslings raised (0.92 goslings/nest), with the highest rates in lowland sites.

Note: If using or referring to this published study, please read and quote the original paper.



Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 19

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust