18 BULLETIN 936, U. S. DEPARTItfE^T OE AGRICULTURE. 
birds suffering from this malady manage to crawl out of the water 
and take refuge in the vegetation, where they lie frequently for sev- 
eral days in a more or less helpless condition. Where coyotes are 
numerous a large proportion of these ducks are captured and eaten. 
As many of them, if not molested, would recover, considerable de- 
struction is thus wrought by the coyotes. During three seasons' work 
the writer has seen where several hundred of these sick ducks were 
killed and eaten by these animals. 
Other mammals. — In some parts of the marsh raairy domestic cats 
run wild and not only destroy numbers of young ducks, but also, 
strange as it ma}' seem, a fair proportion of fully grown ones. 
Haunts of these cats found in the rushes were strewn with ducks' 
feathers and bones.' A few skunks are found on the marshes, but 
minks are very rare. Some have thought that the porcupines that 
wander down here from the mountains in fall feed upon birds, but 
this is entirely without basis, as the porcupine is vegetarian in its 
feeding habits. 
Hogs ranging in the marsh at any season would inevitably cause 
great damage by destroying nests and young and b} T rooting out the 
marsh vegetation. In September, 1916, a drove of hogs made their 
way down the river to the region at the mouth of Browns Overflow 
and feci there for several days before they were driven out. At that 
time there were many sick ducks in this area, and numbers of the 
helpless birds were lying' concealed in the marshy growth lining the 
shore. General conditions at the time were such that if unmolested 
a large proportion of these birds would have recovered, but as it 
happened several hundred ducks were killed and eaten b} T hogs. 
This is only an instance of the damage that may result from such 
invasion, and all measures should be taken to prevent stocking the 
marsh with hogs. Damage to marsh vegetation by these animals 
may be seen in the marshes at Locomotive Springs, near Kelton, 
where large areas of Scirpus have been rooted out. 
• Fish. — Carp have been introduced in Bear River and are enor- 
mously abundant in the marsh region in the delta. In summer they 
frequent the open bays in great droves and do a certain amount of 
damage by digging out the growths of sago pondweed. The quantity 
destroyed is not now excessive, but it might easily become so if 
measures were not taken to keep down the increase of these fish. 
CONCLUSION. 
During three seasons devoted to field work, eleven species of 
ducks and the Canada goose were found breeding in the region in- 
cluded in the Bear River marshes. This covers an extensive area 
in the Salt Lake Valley, Utah, lying in the delta of Bear River and 
extending inland to the sloughs west of Corinne and below Brigham. 
