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Jan., 1909 NESTING OF THE XANTUS MURRELET ON CORONADOS ISLANDS 9 'these islands in company with my friend Mr. Pingree Osburn of Pasadena. In that interval we examined over twenty-five nesting sites, indicated by the broken egg-shells and half as many full sets. Mr. Osburn and Mr. Beck visited the Los Coronados group in early April of this year, and at that time they found ?;wo sets, one fresh and the other heavily incubated. According to some authorities these birds commence breeding as early as the fore part of February further south in the vicinity of Natividad Island; but in this latitude their nesting period evidently commences about April 1, extending to the middle of June. An acquaintance later visited the Islands July 1 but found no Xantus Mur- relets breeding. I believe that the Los Coronados group is the furthest north that they have been found nesting. Reed, in his "Nests and Eggs of North American Birds", states them as lay- ing but a single egg, but I found them laying two to a setting nearly as frequently as one. Of twelve sets five were of two and seven of one. When the set consists of two the eggs will be very different in markings, and even ground color. I be- lieve, too, that when the set is of two, one egg is frequently infertile, as indicated by our finding several nesting places having the broken shells of an egg, evidently hatched, and an infertile egg with it. ?In one set of two, upon which I captured the sitting bird, one egg was infertile. A very handsome egg is laid, in color varying from a dark drab to a very light shade of green, marked either with fine dark brown specks, or lines, usually heaviest at the larger end, and forming a circle around it. In two sets the eggs are heavily blotched evenly over the whole surface. The eggs are elliptical in shape, one end being but slightly smaller than the other and about the size of a coot's eggl Both sexes assist in incubating the eggs. One male and two females were captured on the nests. Like the petrels they vomit a yellowish oil when captured, altho of not such a disagreeable odor. This scent is peculiar to them, and with a little practice one can easily distinguish between their haunts and those of petrels and auklets. Unlike the Cassin Auklet, and Socorro and Black Petrels, among which Brachyramphus hypoleucus nests, they never make burrows in the ground, or even pre[mpt unoccupied ones: Their favorite nesting sites are in the various dark corners of a cave. In one cave, 12 feet by 4 feet, with numerous dark holes, we found where six pairs had been nesting, besides two sets of eggs. This is the only instance on the Islands where we found them colonizing. 0 Their next choice of a nesting site is under a ledge of rock, well back out of reach, and had we not had a crow-bar with us it would have been impossible to reach some nests. In one case I captured a female under a small rock within easy reach; however, she was not incubating eggs. They are not particular as to distance or proximity to the water, some of the nesting sites being a few yards above high water, and others at the top of the Islands several hundred yards from the sea. The eggs are laid on the bare earth with no attempt' at' nest building, except a very shallow hole scratched out where the earth is soft and none at all where it is the least hard. No Murrelets are to be seen about the Islands in the day time, but as soon as it gets real dark their plaintive, half cry and half whistle can be heard. Fresno, California.