NIHOA MILLERBIRD Acrocephalus kingi (Wetmore) 



Order: PASSERIFORMES Family: SYLVIIDAE 



Distinguishing characteristics : A small, plain bird, smaller than a sparrow with a thin, 

 warbler-type bill; gray-brown above and buffy white below. 



Present distribution : Confined to Nihoa Island in the Hawaiian Islands National Wildlife 

 Refuge in the Northwestern Hawaiian Islands . 



Former distribution : Same as present . 



Status : Vulnerable because of very small population and extremely restricted geograph- 

 ical distribution (174 acres). 



Estimated numbers : About 400 in September, 1972, by Bureau of Sport Fisheries and 

 Wildlife personnel. Fluctuates from 300 to 600 for unknown reasons. 



Breeding rate in the wild : Two or three eggs per clutch. 



Reasons for decline : Not known to be declining and no reason known at present why it 

 should . 



Protective measures already taken : Protected by State and Federal law . Its entire range 

 is within the Hawaiian Islands National Wildlife Refuge and thus is protected. Landings 

 on islands restricted and by permit only. Life history study begun. Publicity of refuge 

 status in news media. Status of refuge and need for entry permit included in current 

 nautical charts of area and U.S. Coast Pilot. 



Measures proposed : Preservation of natural environment. Prevent introduction of 

 harmful insects, plants, and animals. Initiate experimental artificial propagation 

 program . Introduction into new range . Increase patrol . Continue ecological and life 

 history research of the species. Continue to publicize critical status and aesthetic and 

 scientific values . 



Number in captivity : None . 



Breeding potential in captivity : Unknown . 



References: 



Bureau of Sport Fisheries and Wildlife Administrative Reports. 

 Wetmore, A. 1924. A warbler from Niboa . Condor 26: 177-178 . 



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