c8 Eaton,. Am Epidemic of Roup in a Crow Roost. Lian 



the pharynx and the anterior portion of the head, including the 

 nostrils and eyes. Often there was a mucous discharge from the 

 nostrils. The eyes were usually blinded by a membrane forming 

 over the exterior of the cornea. Sometimes only one eye was 

 seriously affected, and this was usually the left one, as far as I 

 noticed. If this membrane was rubbed off, the eye looked quite 

 clear again and sight was temporarily restored, but within half 

 an hour the membrane reformed and the patient would flutter 

 about like a bird with the cerebellum destroyed or with the eyes 

 shot out. 



That death ensued from the acute disease and not merely from 

 starvation due to blindness was abundantly proved by caring for 

 sick birds and forcing food down their throats, for they died 

 in nearly every instance. While it is true that those birds which 

 survived the disease were, in every instance, birds that had been 

 blinded in only one eye, we believe that this merely indicates that 

 the roup was less severe in those cases, which was the cause at 

 the same time of the slight affection of the eyes and of the bird's 

 recovery. 



It was believed by many that these Crows were suffering from 

 having wet snow and sleet freeze on their ' faces ' at night, and 

 that one eye often escaped because it was more protected by 

 being tucked under the feathers as the bird slept. There is little 

 to support this theory, in fact it seems almost absurd. There have 

 been many winters much more severe which seemed to have no 

 effect on our crow roosts The disease was an epidemic. This 

 is further shown by the fact that no serious plague appeared 

 either in the Rochester roost or in that near Niagara Falls. 



Nevertheless, the disease disappeared with the coming of 

 warmer weather. A visit to the roost about the last of March failed 

 to discover a single sick bird, although hundreds of corpses were 

 lying about the grove and in the surrounding fields. The last 

 evidence of the disease which I saw was a bird sitting in an 

 open field on the sunny side of the woods on April 6. When 

 approached he flew lazily to a large oak and, lighting on one of 

 the larger branches with some difficulty, proceeded to rub his right 

 eye on the bark. The field glass revealed the fact that his eye 

 was badly swollen, and the surrounding skin was partially bare of 

 feathers. 



