Laysan Island is one of the Northwestern Hawaiian Islands, and is just over a thousand acres of low lying atoll created by coral growth and geologic uplift. Our hunger for guano as fertiliser led to exploitation of the island at the end of the 1800s. Rabbits, hare and guinea pigs were imported to feed the workers and it was not long before the ecosystem was overgrazed and starting to blow away. Some endemic plant and bird species were lost, but the small brown Laysan Duck just hung in there. By 1911 there were an estimated 6-12 ducks left and only seven were counted in 1912. Twenty were recorded in 1923 and the rabbits died out the following year. There is a popular story that in 1930, the Laysan Duck became the most endangered species in the world when it was reported that its population had diminished to just one pair. When the drake disappeared in a storm, all that remained was a gravid female. This widowed bird laid a clutch of eggs, but the nest was then predated by a Bristle-thighed Curlew, Numenius tahitiensis (this shorebird is known to use rocks as tools to crack eggshells). The lone duck re-laid and hatched her second clutch. There may be no truth in this story but it’s a good one! It is certainly documented that by 1950, the population had risen to 33 birds and since then has fluctuated between 100 and 600 birds.
Such a precarious existence led the US Government to plan establishing a wild population on an island less prone to a single disaster such as disease, predation, hurricane or tsunami. After much debate, Midway Atoll, National Wildlife Refuge (NWR), 2,000 km north-west of Honolulu, was selected as the place to create a new ‘insurance’ population. Midway was chosen because it lies within the prehistoric range of the species, has predator-free status, and because it is home to a team of biologists who would be able to manage habitat and study and monitor the survival of any re-introduced ducks. USGS and USFWS staff spent almost two years restoring wetland habitat on Midway, prior to 20 ducks being successfully translocated from Laysan Island to Midway’s Sand Island in October 2004. Another 22 were taken the following year to Sand and Eastern Islands. For the first time in hundreds of years Laysan Duck are now found on three islands, and are flying between Midway’s two islands.
Thanks to the success of this conservation action, the Laysan Duck, once possibly the rarest bird on Earth, has now gained a more secure future.