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 Jan., 1915 BIRDS OBSERVED ON FORRESTER ISLAND, ALASKA 31 ing sides of the island from the shore line to a height of from 400 to 500 feet, their number and distribution depending upon the nature of the soil and the character of the surrounding vegetation. The most favorable nesting sites ap- pear to be the dense spruce woods where the shadows are of such depth that ferns and underbrush find but scanty foothold, and the soil is soft and friable. In such localities over four hundred burrows have been counted in an area six hundred feet square, but where the salmon- and elder-berry are abundant, and ferns form a tangled mat, or rock outcrops are plentiful and the soil thin the nests are of less frequent occurrence or are absent altogether. While no Fig. 14. DIXORXMS OF RHINOCEROS AUKLET RURROWS complete and. accurate count is Possible it is safe to say that not less than fif- teen thousand pairs of these birds found a home on Forrester Island during the past season. Judging from this year's observations the breeding season commences in the latter half of May. At this time the old burrows, which have caved in during the winter or have become clogged with debris brought in by mice, are given a thoroughgoing cleaning, and the accumulation of spruce needles and cones, decayed grass, moss, leaves, stems and earth scraped to the front of the