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500,000 Years Ago Canada Goose Ancestors Blew off Course
Before Polynesians settled Hawai鈥榠 over a millennia ago, three unique species of geese thrived in Hawai鈥榠鈥 n膿n膿 (Branta sandvicensi), n膿n膿 nui (Branta hylobadistes), and the giant n膿n膿 (Branta rhuax). All three were descendants of Canada goose ancestors, which arrived in Hawai鈥榠 approximately 500,000 years ago.
Little is known about the prehistoric giant n膿n膿 but fossil records show that the n膿n膿 nui went extinct shortly after humans settled the islands. Humans hunted them for food and brought in predators including rats and dogs who preyed on the birds and their eggs.
The faster and more agile n膿n膿 escaped the tragic fate of their larger cousins.
Even in the early 19th century they still flourished on nearly all the Hawaiian Islands. On Hawai鈥榠 Island alone there were an estimated 25,000 n膿n膿!
A New Wave of Threats Arrived
Europeans arrived in the late 18th century. N膿n膿 were hunted to feed whaling ships and new settlers. During the plantation era in the 19th and 20th centuries huge swaths of habitat were destroyed and more predators including mongoose were introduced. By 1950 the n膿n膿 population had collapsed with less than 30 n膿n膿 estimated to be living in the wild, all on Hawai鈥榠 Island.
Captive-breeding programs breed n膿n膿 from private collections in Europe, Hawai鈥榠 and the mainland United States in effort to recover the n膿n膿 population. Between 1960 and 1997 over 2,000 n膿n膿 were released on Hawai鈥榠 and Maui. Reintroduction efforts were met with mixed results. Introduced predators, especially mongoose killed many of the newly released n膿n膿 and their offspring.
Kaua鈥榠 Held off on Reintroduction
Conservation biologists did not immediately reintroduce n膿n膿 to Kaua鈥榠 because there was no known history of n膿n膿 nesting on the island. That was until research at Makauwahi Cave Reserve on the south shore of the island exposed deeply buried n膿n膿 bones. The discovery finally provided the necessary evidence to begin planning for reintroduction on Kaua鈥榠.
The first release of a dozen young captive-reared birds took place at 碍墨濒补耻别补&苍产蝉辫;笔辞颈苍迟 National Wildlife Refuge in 1991. Reintroduction efforts continued through 2000.
A Conservation Success Story
With no established mongoose population, n膿n膿 thrived on Kaua鈥榠 and helped bring up the state population numbers. By 2012 Kaua鈥榠 accounted for an estimated 60% of Hawaii鈥檚 statewide n膿n膿 population.
In 2019 the n膿n膿 population was estimated at 3,252 and the species was Federally down-listed from endangered to threatened. While this did remove some of the protections guaranteed by the Endangered Species Act, conservation efforts continue throughout Hawai鈥榠 and Kaua鈥榠. K墨lauea Point National Wildlife Refuge leads several of those efforts.
The 2022 annual n膿n膿 population survey estimated 3,862 statewide with 2,430 of those birds on Kaua鈥榠.
