36 



PACIFIC COAST AVIFAUNA [No. i. 



were secured. Of these but one was a male. Out of 25 which I shot from a flock 

 on April 20th not a single one was a male, and not a single bird was seen with the 

 transocular black. In every case the sex of the specimens was determined by 

 dissection. The weights of five Rock Ptarmigan taken on March 29, ascertained 

 within three hours after they were shot, were as follows: three males, respectively, 

 I 5-16, I 4-16, I 3-16 pounds; two females, i, i 3-16 pounds. They were all in 

 good condition and somewhat fat. The last Rock Ptarmigan seen in the valley 

 was secured on April 23rd, also a female. It seems that the males precede the 

 females to the nesting-grounds. I next met with the species on the foot-hills of 

 the Jade Mountains on May 27 and 28. The oviduct of the single female secured 

 contained a fully-formed egg, indicating that nesting had already begun. Several 

 males were also taken. The birds were apparently confined to the bare mountain 

 sides just at the edge of the snow-line, for the mountains were still unbrokenly 

 white for the upper two-thirds of their height. The males secured at this time 

 (May 28) are still in entire winter plumage, except that a few new dark feathers 

 are to be found by separating the old feathers on top of the head. The transocular 

 stripe is very abruptly defined, rendered more so by abrasion of the bordering 

 white feathers, so that the line of demarcation is quite distinct. The fleshy ccmbs 

 over the eyes were very brilliant poppy red and much enlarged. The female, 

 however, is fully in dark plumage on the upper parts, breast, neck and head, but 

 the remaining lower surface is still mostly white. In the Rock Ptarmigan there- 

 fore the female moults long before the male, just the reverse of the case with the 

 Willow Ptarmigan. The native name for the Rock Ptarmigan is also A-gar'i-uk in 

 common with the Willow Ptarmigan, but the former is also known by a distinctive 

 name, Nik-sak-to'bng'iik. referring to the black on the sides of the head. The 

 natives say this black is so the Rock Ptarmigan, which live on the mountains 

 where the snow covers the ground till mid-summer, will not be blinded by the 

 intense glare. The natives themselves, in the spring before going out on a day's 

 hunt, thoroughly blacken the region around their eyes and across the nose, with 

 soot, to prevent snow-blindness. This is certainly an interesting suggestion, for 

 on May 28, at the snow-line on the Jade Mountains, 2s before stated, the males 

 were still in pure white plumage, except the useful transocular black. The 

 females, moulting as they do much earlier than the males, might not need such a 

 provision. Of course during the winter when the sun is low, there is no such 

 necessity. 



Circus Jnidsonius (Linn.). , • 



Marsh Hawk. 'h 



I saw this species at Cape Blossom on two occasions, July 26 and August 6, 

 '98. Each time the bird was skimming low over the meadows evidently on the 

 lookout for field-mice. Marsh Hawks were frequently noted in the vicinity of 

 bur winter camp on the Kowak, the last of August. They were observed flying 

 over the willow beds nearly every time we went duck shooting across the river. 

 The last seen, an immature in bright rusty plumage, was shot on September 3rd. 

 The following spring, I saw but one Marsh Hawk and this was on the ist of 

 June. 



