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Vol. XXXVIIl 1920 Wetmore, Birds of Lake Burford, N. Mex. ^47 face and flapping their wings made a quick drive forward for'three or four feet making a great boiling in the water with wings and feet. Immediately they resumed the erect position and began the display again. Females were rather shy and when pursued too closely escaped by diving. Males exhibited considerable jealousy and lowering their tails continu- ally drove at one another, the attacked bird usually diving to escape. Occasionally however he stood his ground when the oncoming male either checked and retreated, or occasionally sprang from the water striking on his opponent's head or back with his broad feet and then sliding off. Often the two remained close together striking at one another with their big feet. This was about the extent of their fighting, at which I was some- what surprised as young birds when two thirds grown are very pugnacious when handled. By June 5, a considerable number of Ruddy Ducks were in pairs and swam about when driven from the rushes with the male displaying and the female following him. Females then sometimes gave a curious imitation of the display of their mates, swimming with tails in the air, jerking their heads up and down and then extending the open bill, either without mak- ing a sound or at most uttering only a falsetto qua-er. This odd mimicry was given at times by females that apparently were unmated. At times some of these female ducks produced quite a rattling noise by striking the tip of the bill on the breast, a sound however that was entirely different from that produced by the male. Males were seen in company with sev- eral females as late as June 8. After June 10 the amount of energy spent in display lessened somewhat. Females were often rather nervous over my presence in the rushes and swam back and forth calling ivhap or quep in a curious flat tone. Another note heard from them was Keow Keoiv in a high tone, a one-syllabled call somewhat similar to that of a hen turkey. The breeding season with these birds apparently is late as a female shot on June 18 was not yet lay- ing though the ova were enlarging and the oviduct was about half devel- oped. No nests of this species had been begun at the time of my depart- ure. These birds in preening the feathers of breast and abdomen stood erect in the water treading rapidly with the feet while they did so. Bluebills and other deep water ducks usually lie over on the back or side in order to dress the feathers of the underparts. U. S. Biological Survey, Washington, D. C. (To be Concluded)