REASONS FOR CURRENT STATUS 



There are only 75 whooping cranes in the 

 wild and 27 in captivity (WCRT 1977). They 

 once nested widely over northern North America; 

 nesting is now restricted to a small area in the 

 southern MacKenzie District and northeastern 

 Alberta, Canada. Breeding habitat and wintering 

 habitat have been reduced as a result of drainage, 

 agriculture, the Gulf Intracoastal Waterway, and 

 human settlements. Whooping cranes avoid areas 

 of human disturbance even if the habitat is other- 

 wise suitable (R. Erickson personal communica- 

 tion). 



Cranes were hunted before legal protection 

 was instituted. Losses were particularly acute on 

 the Gulf Coast wintering grounds (Alleh 1952). 

 Accidental shooting probably still occurs when 

 whooping cranes are mistaken for snow geese 

 (Chen hyperborea) and sandhill cranes [Grus 

 canadensis), both legal game in some areas 

 (WCRT 1977). 



Natural factors such as large nesting territories 

 and a very low reproductive rate of one chick per 

 year make recovery slow. The biannual migration 

 covering over 3,800 km usually accounts for some 

 mortahty (Allen 1962). Stormy weather during 

 migration poses a serious threat to the few 

 remaining whooping cranes. The nonmigratory 

 Louisiana population was reduced 50% during a 

 hurricane in 1940 and never recovered (Allen 

 1952). 



There remains the possibility of hazardous ma- 

 terials being spilled on the wintering grounds 

 along the heavily industrialized Texas Gulf Coast. 



PRIORITY INDEX 



Not assigned. 



DESCRIPTION 



Whooping cranes are the tallest birds in North 

 America. Males are almost 1.5 m high, with a 

 wingspan of 2.4 m and an average weight of 7 kg. 

 Females are slightly smaller, with an average 

 weight of 6 kg. Weight can vary 25% seasonally, 

 with the maximum reached in winter. 



The adult plumage is velvety white except for 

 the head and portions of the wings and feet. 

 Forehead, crown, anterior part of occiput, lores, 

 and cheeks are bare except for sparse black hair- 

 like feathers. The skin in this area is warty or 

 granulated, and a reddish color. The bill is a dull 

 pink, proximally changing to dull brownish in the 

 middle and dirty yellow on the tip. The alulae, 

 10 primaries, and 10 greater upper coverts are a 



slatey black. The feet are black with flesh-colored 

 pads. 



Juvenal plumage is a variable mixture of white 

 and buff or brown. The adult plumage is attained 

 in about 1 year. The sexes are similar. 



Vocalizations range from a purring call near 

 young to a low groaning call when approached by 

 humans, to a shrill, bugle-hke 'kerloo! ker-lee-oo.' 

 The latter is known as a unison call and is a defi- 

 nite indicator of pair bonding (R. Erickson per- 

 sonal communication). 



Photographs appear in Allen (1952), McNulty 

 (1966), Novakowski (1966), Walkinshaw (1973), 

 Lowery (1974), Kuyt (1976a, 1976b), Muir 

 (1976), numerous drawings appear in Allen 

 (1952). 



RANGE 



The natural population now nests only in 

 Wood Buffalo National Park, southern MacKenzie 

 District, and northeastern Alberta, Canada. It 

 winters on the Gulf Coast of Texas, in Aransas 

 National Wildlife Refuge and adjacent peninsulas 

 and islands. Its migration route is a nearly 

 straight-line path through east central Texas, cen- 

 tral Oklahoma, central Kansas and Nebraska, 

 western and central North and South Dakota, 

 northeastern Montana, southeastern Saskatche- 

 wan, and northeastern Alberta. 



An experimentally transplanted disjunct 

 population will hopefully nest at Grays Lake Na- 

 tional Wildlife Refuge, Idaho, and winter in the 

 Rio Grande Valley of New Mexico. The migration 

 route passes through southeastern Idaho, north- 

 eastern Utah, southwestern Wyoming, western 

 Colorado, and north-central New Mexico (WCRT 

 1977). 



The crane formerly bred from its present 

 range south through the prairie provinces and 

 northern prairie states, including Illinois, Iowa, 

 Minnesota, and North Dakota, and wintered from 

 the Carolina coast to central Mexico. A geo- 

 graphically isolated breeding population, believed 

 to be nonmigratory (now extirpated), formerly 

 lived in southestern Louisiana. 



RANGE MAP 



Wood Buffalo— Aransas population, Grays 

 Lake Experimental Population and Critical Habi- 

 tat from WCRT (1977) and Federal Register (43 

 FR 20938, 15 May 1978). 



