NATURE NOTES FROM ACADIA

SNOWY OWLS

There is hardly a winter which comes and goes without at least a few reports of the Snowy Owl (Nyctea nyctea) coming from some parts of the state of Maine. In some years great numbers of these birds leave their homes in the Arctic tundra and make their appearance in the New England and nearby states, creating considerable local interest. These winter visitors are fully as large as the Great-horned Owls, are predominantly white in color with more or less grayish-brown barrings, are chiefly diurnal in their habits, and often allow close approach - factors which, in their entirety, account for the conspicuousness of these birds.

On November 10 of this year, one of these birds was captured on Mount Desert Island at Sand Point after being slightly wounded by Mr. G. H. Hamor. After keeping the owl for almost three weeks, Mr. Hamor turned it over to me. By this time its slight injury had healed, and after being photographed the big white bird was liberated in Acadia National Park.

One of the park rangers reported a Snowy Owl on Cadillac Mountain at about the time the individual already mentioned was captured at Sand Point. Mr. Gilley, taxidermist at Southwest Harbor, informs me that two of these birds were taken in late November in the southern reaches of Mount Desert Island - one at Seawall and the other on Great Cranberry Island, just a mile to the east. He also tells me that another was seen in the road at Manset, just below Southwest Harbor, at about the same time.

At the Fred C. N. Parke taxidermists' establishment in Bangor, Maine, Mr. A. A. Carter informs me that three Snowy Owls were received during the month of November. One of these came from Brooksville, another from Criehaven Island, and the third from still another place on the Maine coast. The first two localities are, respectively, but 15 miles west and 40 miles southwest of Mount Desert Island. Mr. F. L. Morill, taxidermist, also of Bangor, tells me of having received one Snowy Owl in mid-November and another in early December of this year.

In a letter dated December 13, Mr. W. J. Clayton, taxidermist and naturalist in Lincoln, Maine, writes that "four or five" of these birds had been reported to him, but that he had received none to mount. Mr. Arthur H. Norton, Curator in the Portland Society of Natural History, reports seeing a Snowy Owl along the city boulevard in Portland on December 9. He writes of approaching to within 30 feet of the bird on two occasions, and goes on to say: "It held a large brown rat in its right hand talons, and carried the prize about as it flew from place to place." In Boston, Mass., on December 29, with the temperature down to the record low of 17° below zero, the Evening Transcript reported a large white owl perched on the Wood End station. From as far westward as Circleville, in southern Ohio, comes a report of this bird, and doubtless there are many other far-away stations where it has been seen this year.

Naturalists have shown considerable interest in the occasional great invasions of Snowy Owls into territory far to the south of their more normal range. I take the liberty of reproducing the following records of Snowy Owl invasions, kindly furnished me by Mr. Arthur H. Norton:

Dr. Alfred O. Gross, careful student of the migrations of these arctic owls, in the latest of two excellent reports on the more recent invasions,* presents a most interesting comparison between the years when these birds fly to the southward in large numbers and the years when maximum numbers of Arctic Foxes are handled by the Hudson's Bay Post at Fort Chimo. The foxes, feeding on very much the same forms of wild life which fall prey to the owls - hares, lemmings, ptarmigans, etc. - are caught in greatest number when their natural food becomes scarce. This same scarcity of food drives the owl far south of its more normal hunting grounds. Dr. Gross shows that "fox years" and years of Snowy Owl invasions synchronize to a remarkable degree.

The "owl years" which Mr. Norton lists are very much in agreement with those reported by Dr. Gross, and are in full accord as far as the years of the great migrations are concerned. William Brewster, editing H. D. Minot's "The Land-Birds and Game-Birds of New England" (1895), makes the following statement on Snowy Owls: "The greatest flight on record took place in the autumn of 1876, when most of the leading New England taxidermists secured from fifty to one hundred and fifty birds each." E. H. Forbush, in his classical "Birds of Massachusetts," writes: "Mr. J. H. Fleming, of Toronto, estimated that at least one thousand of these owls were killed in Ontario alone during another great flight that occurred in the winter of 1901-02, when many owls were killed in New England."

A considerable amount of information is available in regard to the next great invasion which took place in the years 1926-27. (It is of interest that these three most outstanding flights - 1876-77, 1901-02, 1926-27 - are separated by even 25-year intervals). This migration has been summarized admirably in Dr. Gross' earlier paper, in which he reports having received 2,363 records of Snowy Owls from within the borders of the United States. Mr. Arthur H. Norton writes that "The large flight of 1926-27 appeared before the middle of November and came with a rush, while stragglers were noticed well into the spring. No less than three hundred were handled by taxidermists in Maine alone. Many were not shot which were seen by Life Saving crews. A local taxidermist paid only $.50 each against $3 in early years." In a catalog issued by Fred C. N. Parke, taxidermist in Bangor, Maine, is a photograph showing 81 mounted Snowy Owls - all of them received during the 1926-27 invasion. Beneath the picture Mr. Parke makes the statement, "I received 168 of them in less than a month." Mr. A. A. Carter of Parke's establishment informs me that these owls came in so fast they had to be put in cold storage. Most of these birds were received in November. Mr. F. L. Morill, another Bangor taxidermist, mounted 32 Snowy Owls which were killed during this same flight. Mr. W. J. Clayton, taxidermist in Lincoln, Maine, writes me he received "about 100 of them." Although of lesser magnitude than the flight just discussed, the 1930-31 migration was an appreciable one. Dr. Gross reported a total of 1313 Snowy Owls, 497 of which came from within the United States.

Mr. Arthur H. Norton informs me that "While the larger flights come with a rush in the late fall and are prevailingly heavy along the coast, frequently the lesser flights are inshore and come later in the winter." The distribution maps included in the aforementioned reports by Dr. Gross show in a striking manner the concentration of the records along the New England coast.

Are sun spots the distant indirect causes of these periodic invasions of Snowy Owls? According to this theory the sun spots affect the rays of ultraviolet light, directly or indirectly affecting the lemmings and hares, causing pronounced periodic fluctuations in the numbers of these animals, and resulting in very extensive migrations of the owls in years when there is a dearth of food on the tundra. This problem of animal numbers, involving as it does the cyclic rise and fall of animal populations, may be as difficult to solve as it is fascinating to try to comprehend.

When these big arctic raptores descend upon a hunting ground which, to the great majority of them, is entirely new, what do they feed upon? Detailed examination of the stomachs of 94 of these owls, reported by Dr. Gross as having been made by Angell and Cash, taxidermists of Providence, Rhode Island, "resulted in finding 55 of them empty, 24 contained rats, 3 contained squirrels, 7 contained wild native birds, 1 poultry and 4 miscellaneous food." Dr. A. K. Fisher of the Biological Survey (Circular No. 61, p. 13, July, 1907) writes that the stomach of one of these owls contained 14 white-footed mice and 3 meadow mice. He remarks, "The conunon rat appeared in a number of stomachs and seems to be considerably sought after. It is a lamentable fact that this useful bird is slaughtered in great numbers whenever it appears within our limits."

Mr. W. J. Clayton, already referred to in this article, has favored me with the use of notes which relate to his examinations of the stomach contents of these birds. The dates given refer to the great 1926-27 invasion. I have summarized his report as follows:

November 9 - Of 18 Snowy Owls examined, 2 contained remains of hares; 1, a house rat; 1, a shrew; 1, a non-parasitic worm; and the rest were either empty or else contained traces of hair.

November 24 - Of 6 Snowy Owls examined, 2 contained remains of hares; 1, a small bird; and 3 were empty.

November 30 - Of 5 Snowy Owls examined, 1 contained remains of a ruffed grouse; 1, a shrew; and 3 were empty.

December 1 - Of 8 Snowy Owls examined, 1 contained a meadow mouse; 1, miscellaneous matter (bark and paper); and 6 were empty.

January 15 to 29 - Of 9 Snowy Owls examined, 3 contained mice; 2, fish; 1, house rat; 1, small bird; and 2 were empty.

January 30 - Of 2 Snowy Owls examined, 1 contained a house rat and 1 contained 2 mice.

February 18 - 1 Snowy Owl was examined and found to contain remains of a gull.

February 26 - Of 2 Snowy Owls examined, 1 contained 2 mice and 1 contained a white-footed mouse.

In summary, of 51 Snowy Owls examined, 8 contained mice; 4, hares; 3, rats; 2, shrews; 2, small birds; 1, gull; 1, ruffed grouse; 2, fish; 1, worm; 1, miscellaneous matter; 14 were empty; and 13 were either empty or else contained traces of hair. Mr. Clayton remarks that due to the large number of these birds which he was forced to care for in a relatively short period of time, many whose stomachs were found to be empty were not listed in the above report.

- Arthur Stupka