March 3 Lake Merritt, Oakland, Alameda Co., Calif. on the mud. Some of the chasing may be over food, but a lot more of it seems to be of a territorial nature. The areas involved are not large, nor is any one area very consistently, or strenuously defended. Crowing, cackling, purking and goning frequent and widespread. A pinned bird seen but no tags. The great majority of the birds feeding along the shore, and involved in this aggressive behavior, have swollen shields, in fact it looks as if 2/3 a high percentage of the visible birds have swollen shields.-About 200 birds in the fenced area refuge area. Some of these birds seem to have the crown feathers in perpetual depression. Bird 610 in enclosed area at refuge, pin still on, swollen frontal shield, about 35-5/6 enlarged frontal shield present.-A pinned bird with two dangling copper wires seen near Root Landing. One coot on floats near landing was feeding on the droppings of Forster's Terns. There are several birds here that have frontal shields fully as large, and much the same shape, as the birds that have testosterone implants. Noticed that while coots give away to gulls they chase terns - the terns showing no inclination to dispute any area with a