ALASKA LONGSPUR 1619 



uniform habitat, such as Eriophorum tussock tundra, yields such 

 total population figures as 11,800 breeding birds in 10,000 acres. 

 With 1.9 young reared per pair, the total number of fledglings and 

 adults present on this expanse in mid to late summer is about 22,200. 

 Eriophorum tundra is the dominant plant communtiy not only of the 

 Cape Thompson area, but of the entire foothill region of the arctic 

 slope of Alaska (Spetzman, 1959). The lowland areas that are 

 largely covered with Carex meadows may support even greater 

 population densities. 



Plumages. — The natal down is basally light tan in color, shading 

 to yellow and gray for the distal third (Maher, 1964). Dwight 

 (1900) states that the juvenal plumage is acquired by a complete 

 post-natal molt. Maher shows that the nestlings appear feathered by 

 the 7th day and can fly by the 12th day, although the primaries are 

 still growing. The juvenal plumage is described by Gabrielson and 

 Lincoln (1959) and by Dwight (1900) generally as follows: upper 

 parts and sides of head rich buff, tawny buff, or clay-colored, streaked 

 heavily with black; wings and tail deep clove brown; tertiaries and 

 greater coverts edged with "Mars brown" and white-tipped; lesser 

 coverts edged with white, primaries and tail with pale cinnamon; 

 outer rectrices terminally buffy white; below dull white, washed with 

 buff across the throat; the chin, throat, chest, and sides streaked with 

 black. 



The postjuvenal molt begins about 3 weeks after fledging and 

 involves mainly the body plumage and part of the wing coverts. 

 It coincides generally with the timing of the complete molt of the 

 adults. At its end the adults and irnmatures become, for all practical 

 purposes, indistinguishable. 



Dwight (1900) describes the first winter plumage of the male as 

 follows : 



Above, wood-brown and cinnamon streaked with clove-brown, the nape and 

 sides of neck chestnut concealed by wood-brown edgings; lesser coverts edged 

 with wood-brown. Median crown stripe, superciliary line, and anterior auriculars 

 buff, posterior auriculars black. Below, white, the feathers everywhere dusky 

 basally, the sides of chin and a crescentic area on the throat jet black veiled almost 

 completely by long white edgings; the sides and flanks streaked with black. 



Dwight further states that the first nuptial plumage is 



acquired by a partial prenuptial moult beginning in March in the United States 

 which involves the anterior parts of the head, chin and throat. The black 

 feathers of these areas and the creamy white ones of the sides of the head are 

 acquired by moult contrasting with the chestnut collar which is assumed by loss of 

 feather edgings. This moult does not usually extend to the posterior portion of 

 the black throat patch where old black feathers with partly worn-off edgings 

 are regularly found. Wear produces a distinctly black and white streaked 

 appearance above with the collar clear chestnut as if unveiled. 



