THE CONDOR VoL XVII i and 2 were both fairly substantial platforms of oak twigs lined with weed stems; but nest no. 3 was very flimsily constructed of willow twigs and lined with rootlets. At no time were the old birds aggressive. They usually left the vicinity of the nest as soon as we came within fifty or sixty yards. The only note we ever heard them utter was a sort of plaintive whistle. One morning, while working near the nest, my brother saw one of the Kites returning from the direction of the river with something in its claws. While still some distance from the nest it began calling and was quickly joined by the other bird. The first bird remained hovering in the air like a Sparrew Hawk, while the other darted up underneath it, took the food from its claws and returned to the nest while the other sailed away. Sespe, California, August 10, 1915. ADDITIONAL OBSERVATIONS ON THE BIRDS OF THE LOWER COLORADO VALLEY IN CALIFORNIA By A. BRAZIER HOWELL and A. VAN ROSSEM HE FOLLOWING paper is meant to supplement J. Grinnell's "An Ac- count of the i?Iammals and Birds of the Lower Colorado Valley" (Univ. Calif. Publ. Zool., xn, 1914), and contains only such notes on the birds of the region as would seem to be of especial interest in connection with that publication. The present writers spent from January 13 to 31, 1913, camped on the river bottom of the Colorado, with headquarters some four miles below Potholes, on the California side. It will be recollected that this was immedi- ately after the big freeze of two years ago, and for that reason it is possible that the conditions as we found them did not present altogether a normal aspect. Our work was mostly confined to the arrow-weed association with the intervening patches of cultivated ground, and to the bordering mesquite thickets. Some little collecting, however, was done back in the dry arroyo beds, and in the patches of sahuaros a few miles above Potholes. This general locality presents unusually interesting features and merits much further work on the part of ornithologists, especially in the summer and early fall. Marila valisineria. ' Canvas-back. We found this duck to be rather common. Two that were shot on January 21 and 28, respectively, were feeding in an abandoned canal that was thickly surrounded with brush, and in which the water was not over four feet deep. This was obviously a poor place for them, and it was not until we .spent a day, the 2$th, among the sloughs above Laguna Dam that we met with them in any numbers. Here a number of flocks were noted and an adult male secured by a Mr. Reckart. The latter person, who was thoroughly familiar with the ducks of the region, assured us that during some winters, the "Cans" were present by the thousands, while but very few were seen in other years. Dendrocygna blcolor. FuIvous Tree-duck. One of these birds flew cIose over van Rossem on the 17th, allowing him to be positive of its identity. Herodias egretta. Egret. A few may. possibly breed near Yuma, but it is pretty certain that the majority of the birds to be seen here during the winter, have come to us from farther south. We were told on good authority that a flock of thirty or forty had been roosting for weeks on one of the islands above the dam. A number were seen by us on the 2$th, and a male was secured on which the plumes of one side of the back
