12 



BULLETIN 672, U. S. DEPARTMENT OF AGRICULTURE. 



died in far greater numbers than any of the others; the green-winged 

 teal scorned to have the least resistance, and the pintail was a close 

 second; while mallards, spoonbills, and cinnamon teal died in smaller 

 numbers. The redhead was the only member of the group of deep- 

 water ducks that suffered to any extent, though ruddy ducks were 

 found dead occasionally. Sick gadwalls and widgeons were seldom 

 found. Among the great group of shorebirds, avocets and stilts per- 

 ished in great numbers, but only occasional individuals of other 

 species were found. In some years the avocets on the Bear River 

 marshes were almost exterminated. In 1915 a great number of 

 immature snow}- herons perished, and annually a number of sick 

 white-faced glossy ibises were observed. California and ring-billed 

 gulls were common among the sufferers, and many sick and dead 

 coots were found. Land birds were found sick only occasionally. 



The trouble was not entirely restricted to birds, as occasionally 

 muskrats were affected, and frogs (Rana pijnens) that apparently 

 had died from this cause were found at times. On Tulare Lake great 

 numbers of predacious diving beetles (Cybister sp.) were cast up with 

 the dead birds. Other large beetles (Dytiscus sp.) of the same family 

 were found dead or in a more or less helpless condition several times 

 in the Utah marshes. Circumstantial evidence might indicate that 

 these were affected as were the other animals. 



In all, 36 species of birds were found that unquestionably had con- 

 tracted the so-called duck sickness. Thirty-five are listed on field 

 observations made by the writer, and one, the horned lark, is included 

 on the authority of W. H. Meal, of Ogden. Sixteen other species of 

 birds were found under such conditions as to indicate that chey had 

 died from the same trouble. The following list, arranged in sys- 

 tematic order, includes only those known certainly to have been 

 affected: 



Western grebe (.Echmophorus occidentalis). 

 Eared grebe ( Colymbus n. californicus). 

 California gull ( Larus californicus). 

 Ring-billed gull (Larus dclauarensis). 

 Forsterlern (Sterna forsteri). 

 Black tern (flydrochelidon n. surinamensis). 

 While pelican (Pelecanus erythrorhynchos). 

 Mallard (Anas platyrhyncha). 

 Gadwall ( Chauldasmus slrcpcrus). 

 Widgeon ( Hurtca americana). 

 Green-winged teal ( Nettion carolinense). 

 Cinnamon teal (Qucrquedula cyanoplcra). 

 Spoonbill, or shoveller (Spatula clypeata). 

 Pintail (Dafila a. tzitzihoa). 

 Redhead ( Marila americana). 

 Ruddy duck ( Erismatura jamaicensis). 

 Canada goose (Dranta canadensis). 

 White-faced glossy ibis (Plegadis guarauna). 

 Snowy heron ( Egrelta t. thula). 



Coot ( Fulica americana). 

 Avocct (Recurvirostra americana). 

 Black-necked stilt (Himantopus mexicanus). 

 Long-billed dovvitchcr ( Macrorhamphus g. scolopa- 



ccus). 

 Tcctoral sandpiper (Pisobia maculata). 

 Least sandpiper (Pisobia minutilla). 

 Red-backed sandpiper (Pclidna a. pacifica).' 

 Western sandpiper ( Ercuneles mauri). 

 Marbled godwit (Limosafedoa). 

 Lesser yellow-legs (Iliornis flavipes). 

 Killdcer (Qiycchus vociferus). 

 Horned lark (Otocoris alpestris subsp.). 

 Magpie (Pica p. hudsonia). 

 Yellow-headed blackbird (Xanlhocephalus xantho- 



cephalus). 

 Rusty blackbird (Euphagus carolinus).* 

 Cliff swallow (Pctrochclidon I. lunifrons). 

 Pipit (Anlhuss. rubescens). 



i Found at Tulare Lake, Cal. 



- Pound at Lake Bowdoin, Mont. 



