Population Genetics and Emergency Management of Two Kauai Island Endangered Species

Science Center Objects

The Challenge: The Akeke’e (Loxops caeruleirostris) and the Akikiki (Oreomystis bairdi), two species of Hawaiian honeycreeper, are critically endangered bird species endemic to high elevation ohia forests on the Hawaiian island of Kauai.  Both species have suffered severe population declines and range contractions in recent decades.  Akeke’e are currently thought to number ca. 950 wild individuals whereas Akikiki are thought to number ca. 450, and both species occupy ranges of <50 km2.  Captive populations have been established using egg harvesting as a hedge against extirpation in the wild, but the viability of these populations depends on the genetic diversity of captive individuals.

The Science: Genetic diversity is key to the long-term success of captive breeding programs, and it is vital to assess the genetic diversity of captive populations while there is still time to sample additional wild birds.  In collaboration with the Smithsonian Institution and other partners, we are using next-generation genomic methods to assess genetic diversity in captive and wild populations of the Akeke’e and Akikiki to determine (1) what portion of current and past genetic variation is represented by the captive populations, and (2) whether genetic variation in wild populations is geographically structured, and thus whether more diversified geographic harvesting is required. 

The Future: A staggering 13 species of Hawaiian honeycreepers are now extinct, and most other species are endangered.  Captive breeding programs are likely instrumental to the persistence of many of these species, notably the Akeke’e and the Akikiki, whose populations have crashed in recent years.  Our research will evaluate whether current sampling strategies are adequate to capture most genetic variability in these two species, or whether changes in the geographic scope of sampling are warranted.  The results of this work will inform recovery teams and guide ongoing management efforts to preserve these species.