Critical duck bouncing back
…now risen to about 200 individualsThe Critically Endangered Laysan Duck Anas laysanensis had a very successful 2007 breeding season according to U.S. Geological Survey (USGS) and U.S. Fish and Wildlife Service biologists. The year’s total of adults and fledglings on the Midway Atoll National Wildlife Refuge (NWR) has now risen to about 200 individuals.
This is only the third year since this species was translocated. In 2004 and 2005, 42 individuals made a 750-mile voyage across the Pacific and were released at Midway Atoll NWR, managed by the U.S. Fish and Wildlife Service, to increase the species’s geographic distribution and reduce its risk of extinction. With the translocated population more than quadrupling in only three years, researchers are now optimistic that the project will help promote the conservation of this Critically Endangered species.
The Laysan Duck occurs only within the northwestern Hawaiian islands’ Papahānaumokuākea Marine National Monument established in 2006. Laysan Ducks were once widespread across the Hawaiian Islands, but by 1860, they were extirpated from all but Laysan Island, a low-lying island (10 metres above sea level) and home to millions of seabirds. Laysan Island is also protected as part of the Hawaiian Islands “These island ducks could not co-exist with rats, migrate, or disperse away from Laysan Island, so we have translocated birds to restore the species to a larger range”, explained USGS wildlife researcher Dr. Michelle Reynolds, coordinator for the project. “Now Laysan Ducks are found on three rat-free islands for the first time in hundreds of years and are flying between islands at Midway Atoll.”
Survival and breeding of the ducks was closely tracked. Each ‘founder bird’ transported from Laysan carried a small transmitter so that it could be located despite dense vegetation. The post translocation monitoring revealed that the Laysan Duck is capable of flight between the small islands that comprise Midway Atoll and is able to nest in non-native vegetation.
The re-establishment of a second population at Midway Atoll reduces the risk of extinction from chance events such as hurricanes, diseases or the accidental introduction of harmful invasive plants and animals. Discussions are underway about the establishment of a third population on another predator-free island.
"This is marvellous news for a Critically Endangered species and highlights the great work being carried out in these islands", said Ali Stattersfield, BirdLife International's Head of Science.
4th July 2014