LAYSAN DUCK Anas laysanensis (Rothschild) 



Order: ANSERIFORMES Family: ANATIDAE 



Distinguishing characteristics : Teal-sized, dull brownish duck. Similar to the 

 Hawaiian duck but darker, particularly on head of male and with varying amounts of 

 white around eye and on throat. 



Present distribution : Resident on Laysan Island (1,117 acres), Hawaiian Islands National 

 Wildlife Refuge in Northwestern Hawaiian Islands . 



Former distribution : Same as present. 



Status : Currently small and fluctuating population. Subject to sudden destruction and 

 extinction if vegetation feeders such as rabbits or goats, or predators such as rats, cats, 

 or dogs should arrive on the island. Accidental introduction of pest insects or plants 

 could adversely alter ecology of the island. 



Estimated numbers : Almost exterminated by 1923 when only 7 were recorded. Since 



1964 population has fluctuated between 75 (1970) to 475 (1964) . Estimated 175 in September, 



1972. 



Breeding rate in the wild : About 3 to 4 young . Brood success unknown . 



Reasons for decline : Almost became extinct in early part of the century because of 

 destruction of vegetation by feral rabbits introduced by man. Increased when rabbits 

 were eliminated and vegetation grew back. Reasons for current fluctuations unknown. 



Protective measures already taken : Island now posted with refuge warning signs . 

 Protected by Federal and State law . Entry to island restricted and by permit only . Status 

 of refuge and entry by permit requirement information is on official nautical charts of area 

 and in U.S. Coast Pilot . A considerable number are in aviaries in the United States and 

 Europe and are available for stocking purposes if needed. Prevent introduction of harmful 

 insects, plants, and animals. Publicize critical status and aesthetic and scientific values. 

 Patrol of refuge . 



Measures proposed : Continued publicity concerning refuge status and unauthorized 

 landings prohibited by law . Establishment of populations on other Pacific islands . Captive 

 rearing program to include conditioning birds for release into the wild for establishing 

 new populations . Intensify life history studies especially breeding habits and mortality 

 factors . 



Number in captivity : There are over 150 in zoos and private aviaries in the United States 

 and Europe including a few breeding birds at the Pohakuloa State Game Farm, Hawaii. 



Breeding potential in captivity : Very good . 



References : 



Bureau of Sport Fisheries and Wildlife Administrative Reports . 

 Warner, R. E. 1963. Recent history and ecology of the Laysan duck. 

 Condor 65: 2-23. 



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