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 Mar., 1910 A GLIMPSE OF BIRD LIFE ON THEWEST COAST OF MEXICO 75 parr6ts, parakeets and Mexican Caciques (Cassiculus melanicterus). The birds are not hard to approach, tho the parrots and parakeets are somewhat wild. We stayed in San Blas two days this time, which was spent in getting acquainted with and skinning birds. On the ninth of April we embarkt for the Las Marietas Islands, some sixty miles south and four miles from the mainland, known for their considerable guano supply and immense numbers of Blue-footed and Brewster Boobies. The guano is found in large caves and is not the product of our present day birds or bats. The guano of the boobies is considered worthless and on this coast it is the comorant guano that is sought. As we approacht the islands they seemed to be literally covered with boobies, the Brewster greatly exceeding the Blue-looted in numbers. This group of islands consists of two main islands, one of which is about a mile and a half in diameter, composed mostly of piled-up lava. The other, slightly smaller, has a large flat grassy plain and a small spring of fresh water, a few small trees and some patches of cactus. There are several small outlying rocks and it was on these rocks that we found Heerman Gulls ( Larus heermanni) nesting. On these islands the Brewster and Blue-looted Boobies have distinct nesting habits. No Blue-faced Boobies were seen. At the time of our visit Brewster Boobies were all thru their nesting, the young being well able tofly about and fish for themselves. These Boobies make their nests on the high parts of the islands and on the hillsides among the rocks, while the Blue-looted seek the flat plains. Brew- ster Boobies construct a well-made nest of grass, while the Blue-looted simply scratches a hole in the bare earth and deposits her eggs without any lining to the nest. The captain of the ship told me that when he was there, about the 6th of January, Brewster Boobies had young and eggs. We found Blue-looted Boobies with eggs and young in all stages of development. Their colonies never encroacht on those of Brewster's and the two boobies did not seem to associate with each other. Sets of their eggs consist about equally of two or three eggs, and out of hundreds examined only three nests containing four eggs were noted. A singu- lar thing is the large number of runts, and the difference of size of the eggs in the same nest. The eggs when first laid are identical in appearance to those of the cormorants, but soon become badly nest stained. Altho there were hundreds of Frigate Birds about during our stay of five days I did not see any attempt to rob the boobies of their fish, tho when we moved around the colonies the brooding birds would vomit quantities of small fish before flying, which the Frigate Birds would be on the alert to pick up. The boobies do considerable fishing at night and, as the water gave off a phosphorescent light when disturbed, it gave the appearance of flashes of flame when the birds made their dives. The Frigate Birds had their nests in a large tract of wild pineapple plants, which, being exceedingly prickly, made their nests well protected, at least from us. After some very careful work and many stabs I managed to reach a few of the nests and there found young and eggs in all stages of development. The single egg is placed on a platform, flimsily made of twigs and it is a marvel to me how the bird can brood without destroying it. The white downy young often fall victim to their own indiscretion, by falling out of the nest, and once among that wild pine- apple death is inevitable, as testified by many mute witnesses. Tho we made careful search for that exceedingly dainty a. nd graceful bird, the Red-billed Tropic Bird, the only evidence of one was a dried up dead one on the beach. Old friends such as Great Blue Heron, (Ardea herodias). California Brown Pelican, (Pelecanus calzfornz'cus)and Heermann Gull were nesting. At this date eggs of the Great Blue Heron were fresh, California Brown Pelican were