Wednesday 11 April 2012

Laysan duck

Anas laysanensis

Photo by Melinda Webster (Melinda Annie's Website)

Common name:
Laysan duck (en); pato-de-Laysan (pt); canard de Laysan (fr); ánade de Laysan (es); Laysanente (de)


Taxonomy:
Order Anseriformes
Family Anatidae


Range:
This species is endemic to the island of Laysan, in the Hawaii archipelago.


Size:
These birds are 40-42 cm long and weigh up to 400 g.


Habitat:
Laysan ducks use all habitats in the island of Laysan. During the day they are mostly found hidden in dense scrubland, coming out during the evening and night to forage along the sea shores or on the brackish lake inside the island.


Diet:
They mostly eat brine flies Scatella sexnotata, shrimps, snails and other invertebrates such as insect larvae and moths, but will also take grass seeds, sedge seeds and some algae.


Breeding:
The Laysan duck can breed almost all year round, with the breeding season varying significantly between years. The female builds the nest on the ground, under dense vegetation, where she lays 3-4 eggs which she incubates alone for 24-28 days. The precocial chicks leave the nest within 2 days of hatching, but are guarded, brooded, and led to foraging sites by the female for 40-60 days.


Conservation:
IUCN status - CR (Critically endangered)
In the past the Laysan duck occurred throughout the Hawaiian islands, but the introduction of rats lead to its disapearance everywhere but in Laysan. At present, the species has an extremely small breeding range and the global population is estimated at 888-1.064 individuals. The Laysan duck nearly became extinct in the beginning of the XX century, and although the population is currently increasing it shows extreme fluctuations caused by extreme weather, diseases and the accidental introduction of competitors. Some conservation measures, including habitat restoration in Laysan and the relocation of 42 birds  to the Midway Atoll, are under-way to try and save this critically endangered species. 

1 comment:

  1. Dear Francesc,

    I just want to clarify that I am not the author of the photo. I only used a photo available online to illustrate the text that I compiled about this species!

    cheers

    ReplyDelete