THE BIRDS OF THE PRIBILOF ISLANDS. 411 



sea over the Eeef point. This invariably took place every evening during- the latter 

 I>art of my stay on the island. It was always the rule that a dense fog bank hung 

 all around the island at that time, so that even the Eeef point was not visible, but 

 the birds went into the fog without the slightest hesitation. They left their land- 

 marks behind. Several flocks averaging about a hundred birds left nearly every 

 evening from the end of July until I left on August 10. Tlie first arrivals on the island 

 were always adults; the young were not noted for at least ten days. According to 

 Elliott they all leave the islands after the 10th of September. On August 12, 

 when the mountains of the Aleutian cliain were but faintly outlined to the southward 

 of our steamer, a tiarnstone in full straight flight passed the vessel. It was hardly 

 more than a few feet from the surface of the sea and so close to the vessel that stand- 

 ing on the deck I looked directly down on the back of the bird. It continued its 

 course direct for the land as long as I could see it. I saw none at Unalaska during 

 the week next following. Elliott says, "I have met with it at sea 700 miles from the 

 nearest land, flying northwest toward the Aleutian Islands, my ship being 800 miles 

 west from the Straits of Fuca." There is nothing, perhaps, very remarkable about 

 the journey of these birds from the Pribilofs to the Aleutians. Let us trace it. 

 They gather in flocks about p. m., and after the maneuvering that I have already 

 described head directly into the fog and fly southward. We can be sure, first, that 

 many in each flock, and especially the leaders, have made the trip on previous occa- 

 sions, hence they know the way. Now, assuming that they fly at the rate of 30 miles 

 an hour, and knowing that it is about 200 miles to the Aleutians, it would take them 

 about six hours to make the trip. As darkness in that region at that time does not 

 set in until near midnight, they have suflflcient time in which to make the vicinity of 

 the Aleutians. Their rate of travel is undoubtedly faster than 30 miles an hour, so 

 that they readily reach the Aleutians before dark.' As to their movements thence 

 we know little. 



I have been unable to find molting feathers on any specimens, but nearly all have 

 mixed in with the colored summer plumage some of the dull-colored feathers of the 

 winter plumage. Evidently these birds start on their spring migration after the 

 plumage has almost entirely changed. The strength of the bird is then needed for 

 the long journey, so that molting stops and the remaining unchanged feathers are 

 retained. These unmolted feathers are found in the plume feathers of the wing, the 

 tertials, the median coverts, and the scapular plumes. In some cases only a few are 

 found, in others many. Their worn condition, and especially their lack of black and 

 chestnut, render them distinctly noticeable. Fall specimens show these feathers also, 

 so that the evidence of their retaining is complete. It would thus seem that these 

 birds molt all their essentially important feathers before they migrate, the i)urely 

 decorative ones — the tertials, wing coverts, and scapular plumes — changing last and 

 being interrupted in their growth and change by the effects of an extremely long 

 oceanic journey. Few Pribilof specimens show a complete change, while on the con- 

 trary Asiatic specimens are the reverse, thus indicating, probably, that the Pribilof 

 birds winter on the islands of the Pacific, 



' Our steamer made at least 12 knots. The bird mentioned as passing the vessel easily distanced 

 us, going at least three times as fast, and was soon out of sight. 



