LAYSAN DUCK
Anus Laysanensis
WHAT ARE LAYSAN DUCKS?
The Laysan teal is a small duck that inhabits
an island in the Hawaiian Islands. It grows to roughly 14 oz. as an adult. They
are mostly light brown with white-eye rings and a purple green wing patch. The
males have darker feathers around their head, and sometimes their heads take on
a greenish tint. Males also have a blue-green bill with black spots along the
top.
They spend the majority of their
time in vegetation and come out at night to feed. When studying the movement
habits of the birds it is found that they spend over 50% of their time in the
interior, terrestrial, part of the island. With most of the remaining time
spent in or near the lake. The Laysan ducks eating habits are still debated
over, but there are strong studies that conclude their diet contains mainly
insects such as beetles and ants. It has also been recorded that they increase
consumption of brine flies in certain months.
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WHERE DO LAYSAN DUCKS LIVE?
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The ducks are found specifically on Laysan
Island and the Midway Atoll in the string of Hawaiian Islands. Just recently
the duck was also translocate to Kure Atoll at the top of the archipelago. It
was thought that they were
endemic to Laysan Island, until biologists found bones
on many other islands. It is now believed that the Laysan duck once inhabited
the whole of the archipelago.
Populations of the Laysan duck are
hard to estimate because they hide in vegetation most of the day. In the early
1900’s it was estimated that there were only seven birds, and by 1961 the
estimate grew to 688. Although the population declined around 1993 there has
been a strong rebound and there are currently 300-600 birds on the island.
Since the carrying capacity of the island is not very large and the resource
availability is low, the populations should not increase much more.
WHEN AND WHY ARE THEY ON THE ENDANGERED SPECIES LIST?
Listed: Endangered. March 11, 1967.
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The main decline of the Laysan ducks
is still unknown but it is thought that colonizers brought invasive predators
such as the rat and mouse. This limited the ducks to only Laysan Island. In the
late 1800’s their populations sustained another blow when invasive rabbits took
over the island, which led to a great loss of vegetation. The loss of
vegetation brought the population down to seven ducks in 1912. Since then they
have suffered declines from avail flu but recovered well.
The main threats to the Laysan duck
today are its low population size and its range of only two islands. This
leaves the ducks open to extinction from natural disasters or another
introduction of an invasive predator. With a very short range the ducks
survival is based off limited resources. If these resources are altered in any
way it can cause the birds to drop in numbers.
WHAT IS BEING DONE TO HELP?
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| https://www.fws.gov/pacific/ecoservices/documents/LaysanDuckRRP/LaysanDuckRRP.html |
The long-term recovery goals are to
conserve and recover the Laysan so that it can be downgraded to a threatened
species and eventually be taken off the List of Endangered and Threatened
Wildlife and Plants.
To accomplish this goal the ducks on
Laysan Island are being monitored to keep them protected. The U.S. Fish and
Wildlife Service plans to establish additional populations on other areas that
are virtually predator free. There are four main steps to the recovery plan to
ensure that the ducks increase their populations.
1. The
habitat on Laysan needs to be restored and protected.
2.
Young
ducks need to be transferred to viable non-predatory islands in the Hawaiian Islands.
3.
Captive
breeding and the translocation of these ducks to the predator controlled Main
Hawaiian Island sites needs to be implemented.
4.
Further
research on the life history, genealogy, and other areas to further enhance the
recovery of the Laysan duck.
WHAT CAN YOU DO?
You can help by donating money to
the Hawaii Wildlife Center at:
You can also donate to Birdlife
International at: http://www.birdlife.org/worldwide/programmes/preventing-extinctions
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They fund
conservation actions on an array of endangered birds.
You can also help
through education of others. The more people that know the plight of the Laysan
duck the more people that can help.
Sources:
“Endangered Species in the Pacific Islands”
“Laysan Duck”
“Anus Laysanensis”
Laysan duck species fact sheet.
“Return of the Laysan Ducks”
http://www.hawaiiwildlifecenter.org/
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