SAW-WHET OWL 237 



night air remained undisturbed by sounds other than those he pro- 

 duced. Whurdle-whurdle-whurdle he called long and uninterruptedly, 

 in a whistling voice obviously quite devoid of ringing or even metallic 

 quality, and very like that of the Glaucidium of Trinidad, but some- 

 what more guttural. All his utterances were rapidly delivered, evenly 

 spaced, and precisely alike. They altogether failed to suggest the 

 sound of saw-filing." One, circling about the camp on two evenings, 

 September 26 and October 5, "uttered a single staccato whistle, not 

 unlike the familiar pheu of Wilson's Thrush, but decidedly louder and 

 clearer. This was repeated at intervals of half a minute or less for 

 some time." This was then replaced "by a gasping and decidedly 

 uncanny ah-h-h something like that of a Barred Owl, but feebler and 

 less guttural." Another "gave in quick succession four whistles: — 

 hew-hew-hew-hew. ' ' 



W. Leon Dawson (1903) says that the principal note he has heard 

 "is a rasping, querulous sa-a-a-a-ay, repeated by old and young with 

 precisely the same accent, and inaudible at any distance above a 

 hundred feet." The young also make a hissing sound, which is prob- 

 ably a food call, and a bat-like squeaking; Mr. Brewster (1882b) 

 says that this squeaking was discontinued shortly after molting, when 

 it began a new, whistling cry; "this utterance consists of a series of 

 five or six low, chuckling but nevertheless whistled calls, which remind 

 one of that peculiar, drawling soliloquy sometimes indulged in by a 

 dejected hen on a rainy day." 



The courtship notes are referred to above. The interesting bell- 

 like note, with its curious ventriloquial quality, so graphically de- 

 scribed by Audubon (1840), is probably also a courtship call. Mr. 

 Terrill tells me that the saw-filing note is "not much louder than the 

 rasping song of the katydid, and in fact is almost as suggestive of a 

 grasshopper as a bird; it might be described as t-sch — whet-t." 



Field marks. — The saw-whet owl is the smallest of our eastern owls, 

 considerably smaller than the screech owl; it is, however, considerably 

 larger than the pygmy owls. It differs from the screech owls in 

 having a rounded head with no ear tufts. It might easily be confused 

 with the much rarer Richardson's owl, which is only slightly larger, 

 but it has a black instead of a yellow bill; it lacks the black rim of 

 the facial disk, so prominent in Richardson's owl, and the top of its 

 head is streaked, instead of spotted. 



Fall. — The saw- whet owl has generally been recorded as a resident 

 species, but it evidently migrates to some extent, or at least wanders 

 widely, in fall. As with many other apparently resident species, the 

 species may be present at all seasons in regions where the summer and 

 winter ranges overlap, but there has been a general southward move- 

 ment of individuals. W. E. Saunders (1907) and P. A. Taverner and 

 B. H. Swales (1911) have shown evidence of a heavy migration of 



