18 BULLETIN 936, U. S. DEPARTMENT OF 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 many domestic cats 

 run wild and not only destroy numbers of young ducks, but also, 

 strange as it may 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 entirety 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 by rooting out the 

 marsh vegetation. In September, 1916, a drove of hogs made their 

 vay down the river to the region at the mouth of Browns Overflow 

 and fed 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 by 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 Sciryus have been rooted out. 



/•7s//. — 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 Benr 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. 



