12 
BULLETIN 672, U. S. DEPARTMENT OF AGRICULTURE. 
died in far greater numbers than any of the others ; the green-winged 
teal seemed 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 Kiver 
marshes were almost exterminated. In 1915 a great number of 
immature snowy 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 pipiens) 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 they had 
died from the same trouble. The following hst, arranged in sys- 
tematic order, includes only those known certainly to have been 
affected: 
Western grebe (JEchmophorus occidentalism. 
Eared grebe ( Cohjmbus n. calif ornicus). 
California gull (Larus calif ornicus) . 
Ring-billed gull {Larus delauarensis). 
Forstertern (Sterna forsteri). 
Black tern (Hydrochelidon n. surinamensis). 
White pelican (Pelecanus erythrorhynchos). 
Mallard (Anas platyrliyncha) . 
Gadwall ( Chaulelasmus streperus). 
Widgeon (Mareca americana). 
Green-winged teal (Netiion carolinense). 
Cinnamon teal (Querquedula cyanoptcra). 
Spoonbill, or shoveller (Spatula clypeata). 
Pintail (Dafila a. tzitzihoa). 
Redhead (Marila americana). 
Ruddy duck ( Erismatura jamaicensis). 
Canada goose (Branta canadensis). 
White-faced glossy ibis (Plcgadis guarauna). 
Snowy heron (Egretta t. thula). 
Coot (Fulica americana). 
Avocet (Recurvirostra americana). 
Black-necked stilt (Himantopus mexicanus). 
Long-billed dowitcher ( Macrorhamphus g. scolopa- 
ccus). 
Tectoral sandpiper (Pisobia maculata). 
Least sandpiper (Pisobia minutilla). 
Red-backed sandpiper (Pelidna a. pacifica).^ 
Western sandpiper (Ereunetes mauri). 
Marbled godwit (Limosafedoa). 
Lesser yellow-legs (Iliornis fiavipes). 
Ealldeer (Oxyechus vociferus). 
Horned lark (Otocoris alpestris subsp.). 
Magpie (Pica p. hudsonia). 
Yellow-headed blackbird (Xanthocephalus xantho- 
cephalus). 
Rusty blackbird (Euphagus carolinus).? 
Cliff swallow (Petrochelidon I. lunifrons). 
Pipit (Anthus s. rubescens). 
i Found at Tulare Lake, Cal. 
= Tound at Lake Bowdoin, Mont. 
