The North Carolina Zoo is helping to save Mariana Island’s endemic birds from extinction. Introduced brown tree snakes threaten Mariana Island’s small bird populations, with many species found nowhere else on Earth. The Zoo participates in this multi-year, multi-institutional effort by providing funding and technical support for the capture, care, and translocation of threatened birds to snake-free islands where they can thrive. In addition, Zoo staff also participate in local outreach and education events, as well as local capacity building efforts that frequently translate to environmental jobs for local biologists.


An Invasive Snake Wreaking Havoc

The Mariana Avifauna Conservation (MAC) Program’s primary objective is to preserve the native endemic population of birds on the Commonwealth of the Northern Mariana Islands from the threat of an accidentally introduced predator – the brown tree snake. Native to Australia, Papua New Guinea, and some of the surrounding islands, it is believed that the brown tree snake was introduced to Guam (the southernmost Marianas Island) when it stowed away on cargo ships. By the mid 1980’s, nearly all of the birds native to Guam had become extinct in the wild due to predation from this snake. From Guam the snake threatens to disperse northward—again through transportation of goods—to other sections of the Northern Mariana island chain.

 

Translocation as a Conservation Tool

To prevent the same fate for the birds of the Mariana Islands, the MAC Program, founded in 2004, works with several other zoos, the Division of Fish and Wildlife, and US Fish and Wildlife Service to translocate eight priority bird species most vulnerable to snake predation to islands considered to be safe from the snake. The North Carolina Zoo participates in this effort by sending staff out to the islands to help with the capture, care. and relocation of target species. Islands where reintroductions occur were carefully selected to minimize harm to native species already on the recipient islands, as well as to the threatened birds once released. This work included research to assess potential competition between different species, as well as ecological surveys to assess habitat availability. 

In 2018, the project involved capturing two bird species on the island of Saipan and relocating them to neighboring Alamagan. A team of over 20 staff from 10 AZA institutions (including two Zoo staff) trapped 50 golden white-eyes and 50 rufous fantails using mist net techniques. Captured birds were housed individually in a climate controlled bird room where zoo staff weighed, monitored, and feed all the birds up to four times a day. After a thorough health exam from vet staff, all birds were banded with aluminum and color bands which will help biologists monitor individual birds upon release. Birds were then crated up into transport containers and secured in a boat after which staff made the long boat ride to Alamagan. Once at the relocation site, staff strapped the transport boxes and birds into modified backpacks and hiked them in to the release site. All birds were successfully released, and local biologists will return to monitor how the birds do in their new home.

 

Early Signs of Success

Monitoring of relocated bird populations are crucially important to measure project success. If populations increase the project can be considered successful; in contrast, decreases might mean that relocations might need to be halted until impediments to success were identified. To that end, biologists have been monitoring bird populations relocated to snake-free islands since 2012. Monitoring efforts indicate that the project is a major success. For example, in 2011/2012 74 golden white-eyes were released on the island of Guguan; this population increased ten-fold, to 714, by 2016. Even more amazing, the 83 translocated rufous fantails increased to more than 1,000 birds between 2013/2014 and 2016! 

 

Building Local Capacity Through Outreach and Education

A critical component of any conservation project is ensuring buy-in from local people, who will need to continue efforts once a project comes to an end. The Zoo has participated in several education and local outreach efforts to ensure local buy-in. For example, during the annual trips to the archipelago Zoo staff make sure they visit local schools, libraries, and festival to talk to the public about ways that they can participate in protecting their natural heritage. To build local capacity and ensure program continuity, the MAC program also empower local interns to help in the translocation efforts. Several MAC program interns have since secured biologists jobs at local organizations, including the Island’s Division of Fish and Wildlife, one of the project’s main partners.

 

Partners: Commonwealth of the Northern Islands’ Division of Fish and Wildlife, Pacific Bird Conservation, US Fish and Wildlife Service, various other AZA-accredited zoos and institutions.