﻿6 BULLETIN 1359^ U. S. DEPAETMENT OP AGEICULTURE 



Weevils also were well represented, occurring in 24 stomachs. Mis- 

 cellaneous beetles of other groups were represented by casual indi- 

 viduals in a number of stomachs. The identified material is listed 

 in Table 1. 



Diptera. — Flies made up the greatest part of the food of the north- 

 ern phalarope — 32.8 per cent of the whole. The most important 

 element in this division is the larvse of mosquitoes, which alone 

 amount to 6.3 per cent of the entire food. Remains of these larvae, 

 identified usually by their breathing tubes, were found in 29 stomachs, 

 all but one collected in May and June. The strange, long-legged 

 crane fhes were taken twice, while their larvae, aquatic in habit, were 

 found 13 times. Gnats ( Chironomidse) were abundantly represented. 

 Larvae were identified in 22 stomachs, pupae in 17, and adults in 16. 

 The immature stages are found in water, in which they swarm in 

 many localities. 



In the salt lakes of the Great Basin region larvae, pupae, and adults 

 of the alkah flies (Ephydridae) furnish an abundant food. On Great 

 Salt Lake northern phalaropes divide their attention between brine 

 shrimps and the young stages of the alkaH flies. Larvae and pupaB 

 of the latter abound in the shallows and form a rich supply of food. 

 Adult individuals of EpJiydra, found 14 times, are secured as they 

 rest on the surface film of the water or congregate on muddy shores. 

 Larvae and pupae were identified 24 times. So abundant are these 

 alkali flies that cast skins of the pupae drift ashore to form brown 

 windrows, which often extend for miles along the beaches. For- 

 merly the Indians utilized this food supply by gathering the pupae 

 and preserving them for winter use. 



Mollusca. — Small moUusks amounted to 2.7 per cent of the food 

 of the northern phalarope for the period under consideration. All of 

 those identified were snafls (Physa gyrina one and Planorhis trivolvis 

 eight) or other gastropods. 



Miscellaneous. — Dragonfly nymphs (amounting to 0.2 per cent of 

 the total) were eaten by three birds. Arachnida, another minor 

 item in the food, came to 0.1 per cent. Spiders were identified four 

 times, water-mites (Hydrachnidae) twice, and another mite once. 

 Other miscellaneous animal food, a grouping including a variety of 

 forms not found abundantly enough to merit separate tabulation, 

 amounted to 3.8 per cent. In these the larvae of Mayflies were 

 encountered four times and a grasshopper once. A marine worm 

 of an abundant genus (Nereis) and neuropterans were found in the 

 stomachs of two birds each. Fragments of moths in two cases, and 

 skins of caterpillars in two, represented the Lepidoptera; and several 

 small species, the Hymenoptera. These latter include ants and a 

 few parasitic forms, which, from the fact that they must have been 

 picked up by chance, have no particular economic significance. The 

 class of vertebrates was represented by bones of a tiny fish. 



VEGETABLE FOOD 



The vegetable diet of the northern phalarope was made up of seeds, 

 and, though amounting to only 2.8 per cent of the entire food, was 

 taken regularly. In all, vegetable matter was identified in 38 

 stomachs. Among the more important plants represented may be 

 mentioned widgeon grass {Rwppia), eaten 10 times; sago pondweed 

 (Potamogeton pectinatus) , 3; bulrush (Scirpus), 11; and salt grass 



