and its plumes disappear and the entire head becomes uniform black- 

 ish ; the vermilion eyelids fade to a sickly salmon-color ; and the irides, 

 if we may trust scanty observations, become pale bluish. 



Nuptially costumed, the tufted puffins repair in June to the grassy, 

 sloping hillsides of the rocky islets where they make their summer 

 homes, and proceed to renovate the old nesting-burrows, or else to 

 dig new ones. They work intermittently at this. Dr. Leonard Stej- 

 neger noted that on the Commander Islands in the early days of the 

 season the puffins spent only one day ashore in alternation with two 

 days at sea. It is probable that the birds seek and find their mates 

 during these "sea-days," for I have never seen anything like court- 

 ship on shore. 



A steep slope of soil fronting upon the ocean is the favorite nest- 

 ing-site of the tufted puffin. Here tunnels are driven at random to a 

 depth of three or four feet, and so close together that once, on Erin, 

 one of the Olympiades, by placing a foot in the entrance of a burrow 

 and turning on my heel I was able to touch with my hands the en- 

 trances of twenty-five others, all apparently occupied. This may 

 have been an unusually populous section, but if we reckoned at half 

 that rate an acre of ground would carry 2,700 burrows. Hard or 

 rocky soil is not shunned in prosperous colonies, but many efforts to 

 dig here are bafHed. The top soil on precipitous clinging ledges may 

 be utilized also, and even crannies, crevices, and rock-hewn chambers. 

 Upon the Farallone Islands, off the coast of central California, these 

 birds have little opportunity for digging in the earth, and little neces- 

 sity for providing fresh burrows, for crevices and cubby-holes abound 

 — places that have served the purpose no doubt for many centuries. 

 Many eggs, and sitting birds as well, are visible there from the out- 

 side ; while some of the sites are nothing more than the innermost 

 recesses of niches and caves occupied by murres. On the Farallones 

 there is fierce competition between these silent birds and the rabbits 

 which swarm over the rocks. I have seen impulsive bunnies that, 

 fleeing from fancied danger, and taking refuge in the first burrow at 

 hand, emerged more hastily than they went in. The tufted puffin is 

 a dangerous, as well as a determined foe, and a bite from that rugged 

 beak will cut to the bone. 



Although equipped with so formidable a weapon, the birds, in 

 digging their burrows, appear to depend upon their feet. These are 

 provided with nails as sharp as tacks, and the "finish" of the nesting- 

 chamber usually exhibits a criss-cross pattern of fine lines made by 

 their scratching toes. 



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