The feeding habits of this and the other phalaropes are almost wholly beneficial. They live very largely on the larvae of mosquitoes. They also eat crane-fly larvae, which are often very destructive in grass lands and wheat fields. Predaceous diving beetles, which are a nuisance in fish hatcheries, are eaten by them. Dr. Alexander Wetmore's (1925) analysis of the contents of 106 stomachs showed that the food of the Wilson phalarope is mainly insects, of which various flies made up 43.1 per cent, aquatic bugs 24.4 per cent and beetles 20.1 per cent. The remainder of the food included brine shrimps, amphipods, eggs of water fleas, and seeds of various aquatic plants. _Behavior._--Much of the interesting behavior of the Wilson phalaropes has been described under different headings above. In all its movements it is light, airy and graceful. Its flight is much like that of the lesser yellow legs, with which it is often associated; but, when suddenly alarmed, it sometimes flies hurriedly away in a zigzag fashion. On its breeding grounds it often hovers, almost motionless in the air, as the upland plover sometimes does. It swims lightly and buoyantly, but apparently does not dive. It walks about on land actively and daintily, where it is said to resemble the solitary sandpiper. It mingles freely on its feeding grounds with various other species of shore birds. Toward the close of the nesting season the females become very gregarious; as early as June 18, in southern Alberta, we saw them in large flocks, mixed with lesser yellow legs, flying about the marshy lakes. _Voice._--The only note I have recorded is a soft, nasal grunt or subdued quack. Dr. Walter P. Taylor (1912) describes a peculiar nuptial (?) call note "as _oit_, _oit_, _oit_, somewhat resembling the croak of a toad during the breeding season. At the instant of utterance of the note the bird which is calling raises its head somewhat, pauses momentarily in its flight, and its throat bulges slightly." Mr. Saunders calls it a low note sounding like _croo_, _croo_, _croo_. E. S. Cameron (1907) writes: The Wilson's phalaropes, both when feeding and when disturbed and circling on the wing, constantly uttered a low croaking, which at close quarters might be compared to the much louder note of the sandhill cranes, or, at a distance, to the faintly heard barking of a dog. On the other hand, I have heard them give a shrill and totally different call of indecision or satisfaction on their first arrival when hovering over a pool. _Field marks._--The Wilson is larger than the other phalaropes and has a longer bill, neck, and legs. It can be distinguished from other shore birds by its needlelike bill and small head and by the absence of white in its wings. Its spring plumage is, of course, well marked and very beautiful. John T. Nichols gives me the following field characters: