CALIFORNIA LEAST TERN 



Sterna albifrons browni 



KINGDOM Animalia 



CLASS Aves 



ORDER Charadriiformes 



FAMILY Laridae 



OTHER COMMON 



NAMES Least tern, brown tern, 



brown least tern 



DATE 



Entered into SWIS To be determined 



Updates 22 Nov 1978 



LEGAL STATUS 



Federal 



States 



Endangered (35 FR 16047, 13 Oct 

 1970; 35 FR 18320, 2 Dec 1970) 

 Endangered: California 



REASONS FOR CURRENT STATUS 



The least tern nests on sandy ocean beaches 

 and salt flats near lagoons and estuaries. Coastal 

 highway construction, recreational development, 

 and beach cottages have reduced habitat and per- 

 mitted increased access to tern nesting beaches. 

 Feeding areas have been developed, filled in, and 

 polluted (Wilbur 1974). Continuing loss of shore- 



side nesting and feeding habitat, along with high 

 levels of human disturbance and domestic preda- 

 tors at the remaining colonies, have been respon- 

 sible for a decline in numbers up to the present 

 times (Craig 1971, Wilbur 1974). 



DESCRIPTION 



Least terns (subfamily Sterninae) are the 

 smallest of the terns, measing 23 cm long with a 

 wingspread of about 51 cm (Davis 1968). They 

 are characterized by a black cap and white fore- 

 head, grey wings with black tips and leading edges, 

 yellow legs, and a black-tipped yellow bill. The 

 sexes are similar. Immatures have darker plumage 

 and dark bills; the contrast between their white 

 heads and dark eye stripes is often distinctive (K. 

 Bender in Wilbur 1974). It has faster wingbeats 

 than other terns, and can hover longer than the 

 larger terns. 



The California least tern cannot be reliably 

 differentiated from other races of the least tern in 

 the field on the basis of plumage characteristics 

 alone (Burleigh and Lowery 1942). 



Illustrations and descriptions appear in Ridg- 

 way (1919) and Bent (1921). 



PRIORITY INDEX 



Not assigned. 



