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Sept, 1914 SURVEY OF BREEDING GROUNDS OF DUCKS 219 We were thus enabled to visit three of the best known breeding grounds of ducks in the state: the vicinity of Los Barios, in the San Joaquin Valley; the vicinity of (]ridley, in the Sacramento Valley; and the famed breeding grounds of the Klamath Lake region. LOS BANOS, MERCED COUNTY, CALIFORNIA Our stay at Los Barios covered a period of nearly two weeks, May 11 to l(/Iay 24. We were quartered at the club house of the Los Barios (]un Club sit- uated at (ladwall, six miles southeast of Los Barios. Here we were in the heart of the best duck country and found conditions favorable to our work. Practically all of the land in the vicinity of Los Ba5os is owned by the Miller and Lug. Company. By taking water from the San Joaquin River near Mendota and carrying it northward along the hills in two large canals this company has brought large areas of land under irrigation. All of the sections of land which are at all level have been enclosed in levees and are successively flooded so as to cause a continual growth of grass on which cattle are pas- tured. About 150,000 head of cattle are pastured on this "swamped land" in the vicinity of Los Barios. The water in flooded fields varies from a few inches to about four feet deep. In the shallower places sedge (Carex sp.), rushes (Juncus sp.), and salt grass (Distictdis spicata) spring up, whereas rules (bul- rushes and cattails) grow in the deeper parts. The commonest aquatic plant is the yellow water-weed (Jussiaea californica). The higher portions of land which cannot be flooded are covered with Kern greasewood (Spirostachys occidenta- lis). A few sloughs lined with tules carry the surplus water off towards the river, We find, therefore, that these breeding grounds for ducks 'and other birds have been made available through the efforts of man to produce pasturage for cattle. The country is especially well suited to those ducks which choose small sedge-covered islets (see fig. 62) or dense clumps of tules in which to nest. For many years this region has been known as the best of the duck breed- ing grounds in the state, as well as the best of the loafing grounds for water- fowl during the winter. This has been the region where market hunters have most persistently operated. Its distance from the larger cities has alone pre- vented its more wide use for gun club preserves. It has also long been the Mecca of those ornithologists and oologists who were most interested in water- fowl In spite of the activities of such men, however, little has been written as to the results obtained. The best account of the ornithology of this re- gion yet published is to be found in F. M.Chapman's "Camps and Cruises of an Ornithologist" in which an altogether too brief chapter is devoted to "The San Joaquin Valley at Los Ba5os" This one account affords information as to previous conditions (in 1903) in this locality. Anas playtyrhynchos. Mallard. We personally saw but a very few Mal- lards in the vicinity of Los Ba5os, though we were told that the species nests in some numbers along the larger sloughs near the river. We discovered no nests, but succeeded in finding two broods of young. On May 12 while cross- ing a foot bridge across a slough I frightened from a nearby clump of tules a female Mallard with a brood of half-grown young. Some of these dove, while others flopped along the surface of the water. This brood was thought to be at least two weeks old and the eggs must therefore have been laid about the first week in April. A day or two later what was probably part of the same brood was seen in the same locality. On May 18 a female Mallard with a brood of about ten downy young, seven or eight inches long, was noted scurrying across