264 OTUS. 



the low hillocks of which a, greater part of the surface is composed. The miniature val- 

 leys in which there is a slight accumulation of soil, support a somewhat luxuriant growth 

 of poison ivy among which are scattered clumps of wild beach plums that, although, judg- 

 ing from their moss-covered stems and gnarled branches, they have withstood the storms 

 of many winters, have only attained the height of three or four feet. During the first few 

 hours of our visit, we discovered two or three huge nests placed in the tops of this dwarfed 

 shrubbery but could not, at first, make out to what birds they belonged. The island was 

 swarming with three species of Terns and, after a time, we saw a cloud of these birds gath- 

 ering around some object which was suspended in air but the Terns were so numerous that 

 we could not see what it was that engaged their attention, until it moved onward, when 

 we saw that it was a Short-eared Owl. We afterwards found that there was quite a col- 

 ony of them on the place; in fact, we secured four or five specimens. 



A peculiar, bleached variety of the field mouse was very abundant on the island of 

 Muskeget, living mainly on the surface, for they could not well burrow, and they furnished 

 a never-failing supply of food for the Owls which were evidently constant residents. These 

 birds, much to my surprise, would hunt almost constantly by day and, while so doing, 

 were always surrounded by thousands of Terns all of which were screaming so loudly that 

 it was quite impossible to hear any other sound, yet the Owls never appeared to pay the 

 slightest attention to them but would fly about quietly and seemed to be as successful in 

 capturing their prey as if alone. The reason for the antipathy displayed by the Terns was 

 obvious when we came to dissect some of the Owls and found feathers of Terns in their 

 stomachs, mingled with bones of mice. Well-cleaned skeletons of Terns were also numer- 

 ous near the old nests which, we now knew, were built by the Owls, thus proving most 

 conclusively that these birds occasionally varied their diet. 



An examination of the nests of these Owls on Muskeget Island, showed that they 

 were composed mainly of sticks but, as they were bulky structures, it was quite evident 

 that they had been used year after year by the Owls. The eggs must be deposited here in 

 April but further north, on Grand Menan, for example, they are laid a month later. The 

 Short-eared Owls are migratory to a certain degree during the winter, passing, at least, 

 south of Massachusetts. At this season, they are inclined to be gregarious, for they asso- 

 ciate in small companies in their favorite resorts. 



GENUS II. OTUS. THE LONG-EARED OWLS. 



GEN. CH. The sternum is considerably arched, with a moderately rounded keel which does not quite e'iual in height one 

 half the width of the sternum. Outer marginal indentations, twice as deep a* the inner. Coracoids, not very short, bting 

 equal in length to the top of the Iceel and are set on at a rather wide angle. Furcula, quite well developed. Tail and wings, 

 long. There are very long ear tufts. 



All members of this genus have the ear tufts present and they are particularly prominent. The plumage, although 

 downy, is not strikingly long. The eyes are not large and are usually yellow in color. The sterno-trachealis is quite 

 stout, and there is a slender bronchialis, but no other laryngeal muscles. The oesophagus is nearly straight, and opens 

 into a small proventriculus with simple glands arranged in a very narrow, zonular band. The stomach is large, globular 

 in form, with very thin walls. The co3ca are quite long with the blind ends dilated. The fold of the duodenum is long, in- 

 closing a small, but wide, pancreas. Both lobes of the liver are nearly equal in size. There is but one species within our 

 limits. 



