Published January 4, 2020 in the
“Ocean Watch” column, Honolulu Star-Advertiser ©2020 Susan Scott
The gender of Laysan ducks can be told by their bill colors. The male is standing in front of the female. ©2019 Susan Scott
MIDWAY ATOLL >> Although we albatross counters are regularly on the move here, walking back and forth through the colony as we wind our way through the million or so albatrosses at our feet, one bird brings the teams to a halt. This is the Laysan duck, a species so endangered and rare that it’s against the law to approach one within 150 feet. But the charming little ducks don’t know that, and waddle about wherever they please. If people are around, the ducks don’t care.
Laysan ducks once lived on nearly all the Hawaiian Islands. After humans arrived, however, the ducks vanished from everywhere except Laysan, a remote island in Hawaii’s northwest chain.
On Laysan the ducks eat, among other things, brine flies that swarm near Laysan’s shallow salty lake. Nature shows have made famous the image of the roly-poly ducks running in lines as they snap their bills to catch the flies.
But Laysan has had its problems. Introduced rabbits ate all the vegetation that sheltered the ducks and supported their plant and insect food. After the rabbits were removed, and plants restored, natural droughts further hurt the ecosystem, and the duck population dropped.
To create a second wild population, in 2004 and 2005 federal biologists and volunteers transported 42 ducks by ship from Laysan to Midway. Because Midway didn’t have ponds, people made several on two of Midway’s three islands. But the ducks had plenty of food.
Throughout Midway’s decades of human habitation, people unintentionally imported cockroaches, grasshoppers, beetles and loads of other non-native insects. These pests to us are a smorgasbord to the ducks.
Today Laysan has about 500 ducks; Midway, about 1,000. Although numbers that low mean that saving the species is touch and go, the populations at this time are stable.
Laysan ducks are about half the size of Hawaii’s other native duck, the koloa, which is about the size of a mallard. Hawaii’s native ducks both evolved from mallards that eons ago storms blew to the islands.
Laysan ducks develop more and more white feathers on their heads as they age, giving observers clues to the duck’s age. Their life span is about 12 years. Although the little ducks can fly between their two islands here, they don’t go farther.
A huge plus-point for duck watching on Midway is the Laysans’ curiosity and fearlessness. Having no natural predators, the little ducks come out of the bushes after rain to hang out in puddles on Midway’s roads. Neither bicycles, golf carts nor human walkers disturb the lovely brown ducks, which are nearly undetectable until they’re right in front of you. That makes it close to impossible to stay the required 150 feet from this critically endangered species.
There are few moments in the world as thrilling as watching a Laysan duck nonchalantly toddling toward you. Fortunately for us Midway workers, some ducks just don’t know the laws.