130 THE CONDOR Vol. XVI June. Migration date: May 23, 1912. Probably returns south very early, as I have no records later than July-3, 1911, and July 7, 1912. ]?ecurvirostra americana. Avocet.. Common summer resident of the prairies, nesting on the shores of alkaline ponds, and on islands in the larger ones (see fig. 43). Begins nesting late in May, and downy young are seen by the middle of June. Migration date: May 23, 1912. Most of the birds evi- denfly leave in August, but I have record of one September 1, 1911. (]allinago d?li?ata. Wilson Snipe. Found in small numbers all the year around. Nests regularly, but not commonly, in wet marshy meadows, and occurs all winter around warm springs where the water remains open. Pisobia maculata. Pectoral Sandpiper. A small flock seen and one bird secured at Priest Butte Lakes, September 4, 1911. l?i?obia bairdi. Baird Sandpiper. Migrant on the shores of alkaline ponds. Observed August 13 to September 4, 1911. Pi?obia xninutillm Least Sandpiper. Found with the above species on August 13, 1911. l.imosa f?doa. Marbled Godwit. A single individual seen at Priest Butte Lakes, May 26, 1912. ?rota?u? m?la?ol?n?u?. Greater Yellowlegs. Migrant. Observed at Priest Butte Lakes September 4, 1911. ?rota?us fiavil?e?. Yellowlegs. Common migrant. Dates are August 13 to September 4, 1911, and May 8 to 23, 1912. l?I?lodroma? ?olitariu? ?in?amom?us. Western Solitary Sandpiper. Fall migrant. Observed about prairie ponds August 5 to 18, 1911, and on the upper Sun River in the mountains, August 13, 1912. Bartramia lo?gi?auda. Upland Plover. Observed once near Choteau, June 27, 1911. ),?titi? ma?nlariu?. Spotted Sandpiper. Common summer resident along the borders of streams, both on the prairies and in the mountains up to about 5500 feet altitude. Migration dates: May 17, 1912, and August 28, 1911. found several nests near Choteau in gune, 1912; in one of these the eggs hatched on June 22. (See fig. 44.) lqum?niu? am?ri?anu?. Long-billed Curlew. Summer resident. Still common in many places on the prairies, but becoming rare in the more thickly settled parts. 'Begins nesting in May. In late July the young and old birds gather in large flocks about the alkaline ponds, and most of them leave soon after this. Migration dates: September 4, 1911, and April 20, 1912. Squatarola squatarola. Black-bellied Plover. Several birds of this spe- cies observed at Priest Butte Lakes, Septem[ ?,r 4, 1911. Oxyechus vociferus. Killdeer. Abundant summer resident. Nests com- ?nonly throughout the prairies. Migration dates: March 26,' 1912, and Octo- ber 12, 1912. In fall migration the Killdeer evidently passes over in consider- able numbers at night. The call of this bird may be heard late at night, com- ing from overhead, through September and in early October. Dendragapus obscurus richardsoni. Richardson Grouse. Abundant resi- dent throughout the mountains. Breeds on the grass slopes of the upper Tran- sition and lower Canadian zones. Broods of young are very common in such places all summer, feeding *ery largely on grasshoppers. About the middle of September, when the first snowstorms come, the grouse move up the moun- tains; here they winter alongthe ridges of the upper Canadian and Hudsonian
