Burrowing Owl

The Burrowing Owl is a small owl with brownish upperparts spotted with white, whitish underparts barred and spotted with brown, long legs, white eyebrows, and yellow eyes.  Length: 9 in.  Wingspan: 21 in.

The sexes are similar.

None.

Juveniles have unmarked buffy bellies, a buffy wing patch, and mostly unmarked brownish upperparts.

Burrowing Owls inhabit grasslands and open country with bare soil, and are often found in prairie dog towns.

Burrowing Owls primarily eat insects and small mammals.

Burrowing Owls forage primarily at night or at dusk, watching for prey from a low perch and swooping down to capture it, or running to capture prey, or catching insects in flight.

Burrowing Owls are resident in Florida and parts of the southwestern U.S., and they breed in a large portion of the western Great Plains and Great Basin. The population has declined in recent decades.

More information:

Bent Life History

Visit the Bent Life History for extensive additional information on the Burrowing Owl.

Wing Shape

The shape of a bird’s wing is often an indication of its habits and behavior. Fast flying birds have long, pointed wings. Soaring birds have long, broad wings. Different songbirds will have a slightly different wing shape. Some species look so much alike (Empidonax flycatchers) that scientists sometimes use the length of specific feathers to confirm a species’ identification.

• Adult, Washington, Nov.
• From below

Wing images from the University of Puget Sound, Slater Museum of Natural History

Burrowing Owls are often easy to observe during daylight hours as they perch near the entrance to their burrow or on a fencepost.

The persecution of prairie dogs in the western U.S. has led to declines in Burrowing Owls.

The song is a series of cooing.

The Burrowing Owl’s nest is in a burrow in the ground, either excavated by the birds themselves (Florida birds) or in an old burrow of a prairie dog or other mammal (in the western U.S.).

Number: Usually lay 4-10.
Color: White in color.

Incubation and fledging:
The young hatch at about 28-30 days, and begin to leave the nest in about another 6 weeks, though continuing to associate with the adults for some time.

Published by the Smithsonian Institution between the 1920s and the 1950s, the Bent life history series of monographs provide an often colorful description of the birds of North America. Arthur Cleveland Bent was the lead author for the series. The Bent series is a great resource and often includes quotes from early American Ornithologists, including Audubon, Townsend, Wilson, Sutton and many others.

Bent Life History for the Burrowing Owl – the common name and sub-species reflect the nomenclature in use at the time the description was written.

On the wide, open, treeless plains and prairies, west of the Mississippi Valley, and from southern Canada south into Mexico, this curious little owl is, or was, widely distributed even as far west as the Pacific States. It loves the virgin prairies and the unbroken plains but does not take kindly to cultivated land; consequently the encroachments of agriculture have greatly restricted its former range; it is now found ordinarily only in the few scattered places where primitive conditions still remain, untouched by the hand of man.

Much foolish nonsense has been broadcast by careless. observers, or romancers, about the home life of these birds and their happy family relations with prairie dogs and rattlesnakes. No intelligent naturalist now believes any such fantastic stories as have been told, and perhaps believed by some. Dr. Elliott Coues (1874) has explained the basis for these yams, and given us the actual facts, in the following well chosen words:

First, as to the reptiles, it may be observed that they are like other rattlesnakes, dangerous, venomous creatures; they have no business in the burrows, and are after no good when they do enter. They wriggle into the holes, partly because there is no other Place for them to crawl into on the bare, flat plain, and partly in search of Owls’ eggs, Owlets, and puppies, to eat. Next, the Owls themselves are simply attracted to the villages of the prairie-dogs as the most convenient places for shelter and nidification, where they find eligible ready-made borrows, and are spared the trouble of digging for themselves. Community of interest makes them gregarious to an extent unusual among rapacious birds; while the exigencies of life on the plains cast their lot with the rodents. That the Owls live at ease in the settlements, and on familiar terms with their four-footed neighbors, is an undoubted fact; but that they inhabit the same burrows, or have any intimate domestic relations, is quite another thing. It is no proof that the quadruped and the birds live together, that they are often seen to scuttle at each other’s heels into the same hole when alarmed; for in such a case the two simply seek the nearest shelter, independently of each other. The probability is, that young dogs often furnish a meal to the Owls, and that, in return, the latter are often robbed of their eggs; while certainly the young of both, and the Owls’ eggs, are eaten by the snakes. In the larger settlements there are thousands upon thousands of burrows, many occupied by the dogs, but more, perhaps, vacant. These latter are the homes of the Owls. * * * It is strong evidence in point, that usually there are the fewest Owls in the towns most densely populated by the dogs, and conversely. Scarcity of food, of water, or some obscure cause, often makes the dogs emigrate from one locality to another; it is in such “deserted villages” that the Owls are usually seen in the greatest numbers. I have never seen them so numerous as in places where there were plenty of holes, but where scarcely a dog remained.

Courtship: Mrs. Irene G. Wheelock (1904) says: “While the courtship of these queer birds lacks the grotesqueness of that of the sage grouse, it has some features no less amusing; after watching a pair, you will conclude, as I did, that the sofa-pillow caricatures are not far from the truth. Sitting as close together as possible en top of their chosen burrow, they converse in soft love notes not unlike a far-away ‘kow-kow-kow’ of a cuckoo; at the same time caressing with head rubbings and billings.”

Nesting: I have never seen any such large colonies of burrowing owls as those referred to above, and doubt if there are many such left. I have seen only scattering, isolated pairs in North Dakota, Saskatchewan, Arizona, and California. The first nest I dug out was in an old badger hole under a road in North Dakota, on June 13, 1901; the nest was m a cavity, 6 inches high by 8 inches wide, about 30 inches underground; the burrow was about 6 feet long; it and the nest were profusely lined with finely chipped, dry horse droppings. This lining, which usually shows at the entrance of the burrow, seems to be characteristic of occupied nests. Dry chips of cow dung are often used for the same purpose. W. Leon Dawson (1923), in three instances, found the tunnels lined copiously with wings of the black tern. He says that, in California, “whenever food is plenty and the ground inviting, Burrowing Owls are likely to form little colonies, ten or a dozen pairs being found in a stretch of two or three acres.~’

Major Bendire (1892) gives the following comprehensive account of the nesting habits:

When not disturbed, the same burrow is used from year to year; in such a case it is cleaned out and repaired, if necessary. In different localities their choice in the selection of nesting sites varies somewhat. At Fort Lapwai, Idaho, they generally selected a burrow on a hillside with a southerly exposure, while at Walla Walla their nests were always found in burrows on level ground. At Camp Harney, Oregon, where the Burrowing Owls were not very common, one under a large basaltic bowlder seemed to be a favorite site with them, and here they encroached upon the timber in the foothills of the Blue Mountains. At Fort Custer, Montana, I found them mostly on level ground, generally bottom lands, and always at the outskirts of a prairie dog village. On the Pacific coast the borrows of the ground squirrel are more often used for nesting sites, and occasionally those of badgers, which are quite common in some sections. If one of the former is selected, it has first to he considerably enlarged, and which requires a good deal of patient labor on the part of the Owls to accomplish. While stationed at Fort Lapwai I had an opportunity to see an Owl at work enlarging and cleaning out a burrow. The loosened dirt was thrown out backward with vigorous kicks of the feet, the bird hacking gradually toward the entrance and moving the dirt outward in this manner as it advanced. These burrows vary greatly in length and depth, and are rarely less than 5 feet in length and frequently 10 feet and over. If on level ground they usually enter diagonally downward for 2 or 3 feet, sometimes nearly perpendicularly for that distance, when the burrow turns abruptly, the nesting chamber being always placed above the lowest part of the burrow. If in a hillside it will frequently run straight in for a few feet, and then make a sharp turn direct to the nesting chamber. At other times the burrow follows the curves of a horseshoe, and I have more than once found the eggs in such a burrow lying within 2 feet of the entrance and close to the surface of the hill on a trifle higher level; where, had it been known they could have been reached with little trouble. These burrows are generally about 5 inches in diameter, and the nesting chamber is usually from 1 foot to 18 inches wide. After the burrow is suitably enlarged, especially at the end, dry horse and cow dung is brought to the entrance of it, where it is broken up in small pieces, carried in and spread out in the nesting chamber which is usually lined with this material to a thickness of 1 or 2 inches, and I have never found any other material in the nest. In California, however, they are said to line them occasionally with dry grasses, weed stalks, feathers, and similar materials. On one thing most observers agree, namely, that their burrows invariably swarm with fleas.

Dr. A. K. Fisher (1893b) says: “Among the mammals whose deserted burrows are used by this bird may be mentioned prairie dogs, spermophiles, woodchucks, viscachas (South America), wolves, foxes, badgers, skunks, and armadillos. It will be seen from this extensive list that the Owl seldom wants for a home, as one or more of the above species are found in some part of its range. Various authors have stated that the bird sometimes excavates a burrow for itself, but there is no ground for the statement, for in no instance has it been observed in the work of excavation.”

In addition to the usual materials mentioned above, these owls sometimes line their burrows with the remains of their food and a variety of other rubbish. Dr. Coues (1874) says, of a nest reported to him by Dr. C. S. Caufleld: “In the passage leading to it there were small scraps of dead animals, such as pieces of the skin of the antelope, half dried and half putrified; the skin of the coyote, etc.; and near the nest were the remains of a snake that I had killed two days before, a large Coluber P two feet long. The birds had begun at the snake’s head, and had picked off the flesh clean from the vertebra and ribs for about one-half its length; the other half of the snake was entire. The material on which the young birds rested was at least three inches deep.”

Mrs. Florence M. Bailey (1928) writes: “At one nest entrance near Roswell, Mr. Bailey noted a great abundance of dry horse manure, some corn cobs, charcoal, tufts of cow hair, bits of hide, pieces of bone, a child’s woolen mitten, a piece of calico, and other rags, shore lark and other bird feathers, and bits of insects. Part of this material was evidently the remains of food. The rest may have been collected on the principle that Rock Wrens apparently mark their nest hole in a cliff full of holes, as a matter of convenience; or, if prairie dogs ever enter each other’s burrows, the door plate may be to prevent unpleasant mistakes. The smooth brown ejected pellets are easily picked up around the burrows.”

While driving across the prairie in Cochise County, Ariz., on April 26, 1922, we saw a burrowing owl sitting on the mound at the entrance of its burrow, close to the road; on digging it out we found the burrow to be semicircular, measuring 9 feet around the curve but only 5 feet in a straight line from the entrance to the nest cavity, which was only 10 inches below the surface. The female was sitting on nine fresh eggs.

Eggs: Bendire (1892) says:

The number of eggs laid by the Burrowing Owl varies from six to eleven. From seven to nine are more often found, while sets of ten and eleven are not especially rare, and Mr. Walter E. Bryant, of Oakland, California, found one of twelve near Carson, Nevada. The eggs are usually found in a single layer and disposed in the form of a horseshoe. On two occasions in extra large sets, I found them placed on top of each other.

It is astonishing how they manage to cover them all, but they do, and it is rare to find an addled egg * * *

The eggs of the Burrowing Owl, after they are washed, are pure white in color, but as taken from the burrow they are usually much soiled by the excrement of the numerous fleas inhabiting these domiciles, and bear then no resemblance to white. They are much more glossy than most Owls’ eggs and are usually rounded ovate in shape. The shell is close grained and smooth, hut in some sets it is strongly granulated.

The measurements of 214 eggs in the United States National Museum average 31 by 25.5 millimeters; the eggs showing the four extremes measure 34 by 27, 31 by 28, 28 by 25, and 32 by 24 millimeters.

Young: Major Bendire (1892) says that “both parents assist in incubation, which lasts about three weeks, and but a single brood is raised in a season. A second, and somewhat smaller set is frequently laid in the same burrow or in another close by, if the first eggs are taken.”

Grinnell, Dixon, and Linsdalc (1930) observed an interesting habit of young burrowing owls, of which they say:

When the burrow had been dug out two-thirds of the way to the end, a buzzing screech was beard that seemed so nearly like a muffled rattle of a rattlesnake that it was bard to feel sure that there was no snake in the burrow. As the digging proceeded this noise was beard more and more clearly. Finally the terminal cavity was opened up, disclosing only the six young owls. Their main defense was the utterance of the rasping, penetrating, rattling hiss, nearly like the angry buzz of a rattlesnake when disturbed on a warm day. The hill clicks which were produced less frequently than the rattling notes were rather weak. The latter utterance was deterrent in our case; might it not be so as regards carnivores that dig out or enter burrows such as the burrowing owls inhabit? Badgers, coyotes, weasels, and possibly such rodents as marmots and ground squirrels might thus be deterred from molesting the owls.

John McB. Robertson (1929) gives the following account of the methods employed in feeding the young, after they were large enough to come out of the nest:

The young owls were usually in a compact group on the highest part of the mound, while the adult, only one adult being observed, bad several lookout stations, the nearest one being the top of a pile of haling wire and other junk on the alkali flat, and the others were fence posts at various distances from the burrow.

The usual program was as follows: The adult, frequently looking skyward, sighted some flying insect passing over, launched out in pursuit, climbing rather laboriously upward at a sharp angle and sometimes spirally, often to a height of 150 feet or more, and on overtaking the flying prey seized it with one foot. Then came a pause during which the prey was transferred to the beak, then a long glide, on set wings, directly to the nest. The young, on seeing the adult coming with food, rushed down the slope toward it, and then turned and rushed back as the adult passed over their heads to alight on the highest point of the mound. Then came a scuffle that would have done credit to a football game. However, actual possession of the coveted morsel seemed to be respected, and the lucky youngster was allowed to devour it at leisure. After a brief pause the adult returned to a vantage point to watch for more game. * * *

As the young grew older and learned to fly they sometimes flew toward and intercepted the adult before the burrow was reached; this was successful only in cases where the adult flew close to the ground after making a low, or a ground, capture. The adults sometimes ate the prey themselves, and in this case it was sometimes held up to the beak with one foot while the bird stood on its perch.

On one occasion a weasel appeared, crossing the pasture, and was immediately assaulted by the owls. The young were flying quite well at this time and they joined in the attack, hovering over the scurrying weasel and swooping at it front behind ‘with extended claws. The weasel paused and faced them at times and then hurried on; I could not be sure that they actually struck him, but they came close enough to do so. Birds from other families joined the fun, and at one time there were ten owls in the air together. The weasel was escorted about one hundred yards before the chase was abandoned.

Plumages: The newly hatched young burrowing owl is but scantily covered, on the feather tracts only, with grayish-white down, basally dusky; bare skin shows between the feather tracts, even after the juvenal plumage has begun to grow. This first plumage seems to appear almost simultaneously on all the feather tracts and on the wings and tail. By the time the young bird is half grown it is completely covered with the distinctive juvenal plumage. In this plumage, the crown, hind neck, and back are plain, dull, grayish brown to buffy brown, most grayish on the head; the wing coverts are mostly light buff, but the rest of the wings and the tail are like those of the adult; the under parts and upper tail coverts are pale buff and unspotted, with a suffusion of “wood brown” across the upper chest. This plumage is worn until July or August, when a complete molt of the contour plumage begins on the sides of the breast, the scapulars, and wing coverts; this molt is completed in September, when the first winter, or practically adult, plumage is acquired.

Adults have a complete annual molt in August and September. Many birds show so much fresh plumage in spring that I suspect they may have a partial prenuptial molt of the body plumage, though I have not been able to detect it. The wear and tear on the plumage, owing to subterranean life, might well make such a change desirable.

Food: The burrowing owl is unquestionably one of our most beneficial birds of prey, for it destroys very few small birds, mainly to feed its young, and it subsists almost entirely on insects and injurious rodents, which it destroys in enormous numbers. Fortunately most ranchmen and farmers appreciate this fact and do not persecute it.

Its insect food includes grasshoppers, locusts, beetles, Jerusalem crickets, mole crickets, black crickets, caterpillars, dragonflies, and various other insects, many of which it catches OR the wing. Major Bendire (1892) says:

They hunt their prey mostly in the early evening and throughout the night, more rarely during the daytime. As soon as the sun goes down they become exceedingly active, and especially so during the breeding season. At such times they are always busy hunting food, and go and come constantly, and they may often be seen hovering suspended in the air like the Sparrow Hawk, locating their prey or darting down noiselessly and swiftly, and grasping it with their talons without arresting their flight an instant. The actual amount of food a pair of these birds require to bring up their numerous family, generally averaging eight or nine, is something enormous. Each Owl will eat fully its own weight in twentyfour hours, if it can get it.

Dr. Fisher (1893b) says that “of 32 stomachs examined, 3 contained small mammals; 3, lizards; 3, scorpions; 1, a centipede; 30, insects; and 1 was empty.” In his table of stomach contents, he records seven stomachs that contained between 40 and 60 locusts and other insects each, and he says that “this little Owl will chase and devour grasshoppers until its stomach is distended to the utmost.”

Next in importance come the mammals, including mice, rats, and ground squirrels of various species, young prairie dogs, young cottontails, pocket gophers, chipmunks, shrews, and even bats. To test the ability of these owls to kill ground squirrels, Major Bendire (1892) experimented with a pair he had in captivity; he writes:

I fed a pair of these Owls four live full-grown Townsend’s ground squirrels in one day, besides the carcasses of five small birds that I had skinned, and was astonished at the ease and celerity with which these rodents were killed and the small amount of resistance they made. I watched the proceedings through a small bole in the door. As soon as a squirrel was turned loose in the room with the Owls, one of them would pounce on it, and, fastening its sharp talons firmly in the back of the squirrel, spread its wings somewhat, and with a few vigorous and well-directed blows of its beak break the vertehrm of the neck, and before it was fairly dead it commenced eating the head. This was always eaten first and is the favorite part. Next morning there was but little left of squirrels or birds, and the two Owls had certainly eaten considerably more than their own weight in the twenty-four hours.

C. B. McBee (1927) reports large numbers of mice found in burrows of these owls near Kiona, Wash.; one burrow contained 25 mice and 3 sage rats, another 15 mice and 2 sage rats, and others lesser numbers; m examining a number of their nests, he found only one bird, a young dusky homed lark. Among the birds taken, horned larks seem to be oftener reported than any other species. F. A. Patton (1926), writing from South Dakota, says: “In examining these burrows I found about the entrance, and down in the burrows, quantities of feathers of the Desert Horned Lark, mostly wing and tail feathers. Digging into the burrows I would find from four to six partly eaten larks, mostly young birds just flying; also usually a less amount of partly eaten field mice. Not a burrow did I find but showed evidence that more than fifty per cent of the food of these owls were larks, which were being killed by the thousands.”

Feathers, or other remains, of least sandpiper, black-headed gross beak, western meadowlark, Bell’s vireo, and various sparrows, or other small birds, have been found in or about the burrows, but most observers agree that they form only a small part of the total food. Bendire never found any bird remains in any of the many burrows that he examined.

Various miscellaneous items enter into the food of the burrowing owl, such as lizards, snakes, frogs, toads, salamanders, fishes, scorpions, centipedes, and myriapods. Paul Thompson writes to me that he has found the remains of a cecropia moth, two forewings and head, at the entrance of a burrow, and that the remains about burrows near ponds and creeks consist largely of crayfishes. In one case he found a wing and a leg of a burrowing owl at the entrance of a burrow; this owl may have been killed on a nearby road and brought to the burrow to be eaten.

A comprehensive study of the food habits of burrowing owls in northwestern Iowa has recently been published by Errington and Bennett (1935).

Behavior: : As an exception to the rule, stated in my opening paragraph on this species, it is interesting to note that Clinton G. Abbott (1930), when he came to San Diego in 1921, found burrowing owls living: in well-settled parts of the city. A certain individual roasted daily in a pepper tree in front of the Central Y. M. C. A., almost in the heart of the business district. On El Cajon Boulevard, which was a well-traveled thoroughfare even in those days, Burrowing Owls could often be seen perched on the side-walk curb. They lived in the culvert drains under the intersecting streets.

The paving of this boulevard has driven these birds away, and the Y. M. 0. A. “Billy” has gone, yet in spite of San Diego’s present 150,000 population Burrowing Owls still subsist wherever there is any extent of vacant land. In quiet streets they can sometimes be seen hawking about the arc-lights at night and settling on the pavement below: probably in pursuit of moths. On Reynard Way, which is a short-cut between down town and the Mission Hills residential district, these Owls are common, because many of the sloping lots on each side have not yet been built upon. Even in broad daylight a “Ground Owl” may often be seen standing upon some advertising sign, apparently unconcerned at the passing stream of automobiles.

Dr. Coues (1874) has given a far better word picture of this curious owl than I can write, as follows:

As commonly observed, perched on one of the innumerable little eminences that mark a dog-town, amid their curious surroundings, they present a spectacle not easily forgotten. Their figure is peculiar, with their long legs and short tail; the element of the grotesque is never wanting; it is hard to say whether they look most ludicrous as they stand stiffly erect and motionless, or when they suddenly turn tail to duck into the hole, or when engaged in their various antics. Bolt upright, on what may be imagined their rostrum, they gaze about with a bland and self-satisfied, but earnest air, as if about to address an audience upon a subject of great pith and moment. They suddenly bow low, with profound gravity, and rising as abruptly, they begin to twitch their face and roll their eyes about in the most mysterious manner, gesticulating wildly, every now and then bending forward till the breast almost touches the ground, to propound the argument with more telling effect. Then they face about to address the rear, that all may alike feel the force of their logic; they draw themselves up to their fullest height, outwardly calm and sell-contained, pausing in the discourse to note its effect upon the audience, and collect their wits for the next rhetorical flourish. And no distant likeness between these frothy orators and others is found in the celerity with which they subside and seek their holes on the slightest intimation of danger.

Dr. Fisher (1893b) says: “The flight is rather laborious, irregular, and somewhat jerky, and is seldom of long duration. The bird rarely rises high in the air, but passes noiselessly along the ground, and when alighting drops very much after the manner of the woodcock.” I should hardly call the flight laborious or jerky; it seemed to me quite strong and easy, and I was always impressed with the large expanse of wing on such a small body. About its breeding grounds it makes only short flights at low elevations from one perch to another, keeping hardly more than a short gunshot range from the intruder. The fact that it nests on several islands off the Pacific coast, and that it has alighted on ships at sea, shows that it is capable of prolonged flights. It is usually seen perched on the level ground, or on the little eminences at the entrances of burrows, more from necessity than choice; but I believe that it prefers to perch on fence posts, wire fences, low bushes, or even trees where these are available, selecting the best lookout points it can find. Some observers have reported it as shy, especially on bright, sunny days, but I have generally found it rather easy to approach; once on a dull, cloudy day I was able to crawl up to within a few feet of one and photograph it at short range.

Burrowing owls seem to have a curious habit of following a moving animal, perhaps to secure whatever small game may be stirred up by it. Aldo Leopold (1923) mentions one that “made a daily practice of pursuing a bird dog when the dog was turned loose for exercise near the golf links of the Albuquerque Country Club. * * * When the dog first appeared on the owl’s range, he would chase the owl for a short distance. When this was over, the owl would chase him for distances up to 150 yards, flying about five feet behind and above him as the dog hunted.” E. S. Cameron (1907) says that “in summer these owls have a habit of making short flights along the wire fences in front of horses, perching on the wires until approached quite close.”

Voice: The vocal performances of the burrowing owl are not very elaborate and consist mainly of two very different notes, the cackling alarm note, caclc-caclc-caclc-cack, given as it darts into its hole or flies away, and the so-called love song, a rapidly uttered, cooing note, given in the spring on its nesting grounds. Claude T. Barnes says in his notes: “As I approached, the languid owl flew to a nearby post uttering occasionally a raucous twit, or t t, t t, twut.” Bendire (1892) writes:

They appear to be mated when they make their first appearance in the early spring, and I believe remain paired through life. At this season, where they are abundant, and they are generally found in little colonies of several pairs at least, their peculiar love note can he heard on all sides about sundown; it reminds me more of the call of the European Cuckoo (Cuculus canorus) than anything else, a mellow sonorous and far-reaching ‘coo-c-n-n’, the last syllables somewhat drawn out, and this concert is kept up for an hour or more. These notes are only uttered when the bird is at rest, sitting on the little hillock surrounding its burrow. While flying about, a chattering sort of note is used, and when alarmed a short shrill ‘tzip-tzip.’ When wounded and enraged it utters a shrill scream and snaps its mandibles rapidly together, making a sort of rattling noise, throws itself on its back, ruffles its feathers, and strikes out vigorously with its talons, and with which it can inflict quite a severe wound.

Field marks: The burrowing owl could hardly be mistaken for anything else. It is the only small owl that habitually lives on the ground in open places; the short-eared owl is much larger and frequents grassier places. A small owl, with very long legs, a very short tail, a compact, rounded bead and yellow eyes, is sure to be a burrowing owl. Its curious bobbing habit also is distinctive.

Enemies: Burrowing owls have few natural enemies, though rattlesnakes doubtless destroy some eggs and young. Dr. J. F. Brenckle suggests in his notes that the nests may sometimes be invaded by cats and says that “the highway seems a favorite feeding ground, and, with the bright lights and speed of cars, many are killed or wounded.” Undoubtedly many are killed by the indiscriminate use of carbon disulfide in campaigns against ground squirrels; no distinction is made between the holes occupied by squirrels and those in which the owls are nesting; all the holes are poisoned and sealed, thus killing many a family of owls, the farmer’s best friends.

Migration: Throughout the more northern portions of their range burrowing owls are more or less migratory. Bendire (1892) says: “In Washington, Idaho, and Oregon, they appear to migrate about the beginning of November and sometimes earlier, returning to their summer homes in the early part of March. At any rate, without actually examining any of their burrows during the winter months, to ascertain their presence, I never saw one of these birds, as far as I can remember, sitting in front of these at such times, and I have lived where they were very common and certainly would have noticed one occasionally if actually about.”

Dr. J. F. Brenekie, who has banded some 300 burrowing owls near his home in Northville, S. Dak., has sent me some interesting notes on his returns. Many of the returns were of birds killed on highways at nearby points, and one was killed on a railroad track. Of the more distant returns, one was found wounded on a highway near Royal, Nebr., on October 1, 1931; one was captured at Gunter, Tex., on January 7, 1932; one was taken at Edmond, Okla., on December 12, 1932; and one was captured at Willow, Okla., on Apr11 4, 1933. Evidently some of these owls indulge in extensive migratory movements.

Winter: Apparently some of these little owls remain on their northern breeding grounds all winter, for Dr. G. S. Agersborg (1885), referring to “southeastern Dakota”, says: “In the winter as many as twenty of these birds may be found nestling together in one hole. They are always at such times abundantly supplied with food. I have found at one time forty-three mice and several Shore Larks scattered along the run to their common apartment. They forage in fine weather and retreat to their dirty adobes when cold weather threatens.~~

Dr. Coues (1874) quotes Townsend as saying: “I found both the prairie-dogs and the Burrowing Owls abroad and very active on pleasant days in December and January, on the plains of Western Kansas, although the temperature often fell nearly to zero (Fahrenheit) during the nights following. I was also assured by old residents of the plains that both these animals are frequently seen abroad during pleasant weather throughout the winter.”

DISTRIBUTION
Range: North America to southern Canada, parts of the West Indies, Central and South America.

Breeding range: The burrowing owl breeds north to southern British Columbia (Okanagan); southern Saskatchewan (Many Island Lake, Crane Lake, Rush Lake, Moosejaw, and Indian Head); and southern Manitoba (Oak Lake, Riding Mountain, Portage la Prairie, and Kildonan). East to Manitoba (Kildonan); Minnesota (Swift County, Montevideo, and Sherburn); Iowa (Granville, Paton, Ashton, and Wall Lake); eastern Nebraska (Neligh, Horth Loup, and Wilber); Kansas (Portis, Garden Plain, Harber, and Medicine Lodge); Oklahoma (Fort Reno, Norman, and Mount Scott); western Texas (Banham and Austin); southeastern Florida (Fort Drum, Fort Thompson, Ilialeah, and Miami); Bahama Islands (Eleuthera, Cat Island, and Great Inagua); Dominican Republic (Monte Cristi, Sosua, Santiago, Tubanos, Bani, and Beata Island); Lesser Antilles (Nevis, Antigua, and Guadeloupe); probably British Guiana; Brazil (Para, Bahia, Campos, and Itapetinanga); Uruguay (Cerro Largo, Rocha, and Maldonado); and Argentina (La Plata, Dolores, Cape San Antonio, Bahia Blanca, Rio Negro, and Cape Espiritu Santo). South to southern Argentina (Cape Espiritu Santo); and Chile (Rio Imperial). West to Chile (Rio Imperial, Molina, Coquimbo, and La Seren a); Ecuador (Puna Island, Santa Elena, and Concepcion); Panama (Chiriqui); Guatemala (San Jose, Duenas, and San Geronimo); Oaxaca (Tehuantepec); the “plains of Colima”; Revillagigedo Islands; Baja California (San Jose del Cabo, Mira Flores, Todos Santos, El Rosario, Cedros Island, and Calexico); California (San Clemente Island, San Nicolas Island, Santa Rosa Island, Alcalde, Paraiso Springs, Marneda, Oakland, East Park, Alton, and Tub Lake); Oregon (Mud Creek, Silver Lake, Corvallis, Scio, and The Dalles); Washington (Yakima Valley, Cheney, and Riverside); and British Columbia (Osoyoos Lake and Okanagan).

The range as above outlined is for the entire species, which has however, been separated into several geographic races and is, moreover, discontinuous. For example, in the Eastern United States the only region where the species is found regularly is in southern Florida, which is occupied by the Florida burrowing owl (Speotyto c. tioridana). This form also is found on the Bahama Islands. The Hispaniolan burrowing owl (S. c. troglodytes) occurs chiefly in Haiti and the Dominican Republic; the Guadeloupe burrowing owl (S. c. guadeloupensis) and the Antigna burrowing owl (S. c. amaura), both of which are probably now extinct, are confined to a few islands of the

Lesser Antilles; and the birds of the Revillagigedo Island group, off the west coast of Mexico, has been named S. c. rostrata. The typical form S. a. cnnicularia is South American.

The western burrowing owl (S. a. hypugaea) occupies the North American portion of the ranges, except for Florida. It is migratory in the northern areas, and in some parts of Central America it apparently occurs only as a winter resident.

Winter range: As stated above, this species is migratory only in the northern parts of its range. It will occasionally remain throughout the winter almost to the limits of the breeding range but ordinarily at this season it is found north to California (East Park, St. John, and Chico); southern Arizona (Parker and Tucson); southern New Mexico (Mesilla Park, Tularosa, and Carlsbad); Texas (Lipscomb, Decatur, and Corsicana); and southern Florida (Miakka Lake, Istokpoga, and Fort Drum).

Spring migration: Early dates of spring arrival are: Kansas (may winter rarely in southern part): Wellington, March 22; Wichita, April 7; Ellis, April 8. Nebraska (winters rarely): Beatrice, March 24; Valentine, April 6; Antioch, April 8. Iowa: Sioux City, March 20; Ashton, April 22. South Dakota: Fort Pierre, April 5; Forestburg, April 6; White River, April 15. North Dakota: Marstonmoor, April 7; Jamestown, April 10; Argusville, April 20. Minnesota: Sherburn, April 18. Manitoba: Margaret, April 14; Aweme, April 24. Saskatchewan: Indian Head, April 24. Colorado (winters rarely): Grand Junction, Wiarch 23; Loveland, March 28; Denver, April 14. Utah: Salt Lake County, April 17. Wyoming: Wheatland, March 12; Laramie, April 15. Idaho: Meridian, March 5; Deer Flat Refuge, March 18. Nlontana: Corvallis, April 15; Billings, April 21; Fort Custer, April 25. Nevada (may winter rarely): Carson City, April 26. Oregon (winters rarely): Camp ilarney, March 13; Klamath Lake, March 31. Washington (may winter rarely): Walla Walla, March 1; North Yakima, March 7; Prescott, March 19. British Columbia (winters rarely in extreme southern part): Okanagan, April 2; Osoyoos Lake, April 6; Penticton, April 15.

Fall migration: Late dates of fall departure are: Washington (may winter rarely): North Yakima, October 1; Grays Harbor, October 19. Oregon (winters rarely): Cold Springs, October 14. Nevada (may winter rarely): Overton, November 22. Montana: Big Sandy, September 14; Fort Benton, September 20. Idaho, Deer Flat Refuge, November 1; Meridian, December 14. Wyoming: Hutton Lake, October 5; Midwest, October 7; Wheatland, November 2. Colorado (winters rarely): Boulder County, October 13; Jackson County, October 26; El Paso County, November 2. Manitoba: Treesbank, September 25; Oak Lake, October 4. North Dakota: Stump Lake, September 29; Jamestown, October 1. South Dakota: Forestburg, October 1; Ha.rrison, October 18. Iowa: Woodbury County, October 5. Nebraska (winters rarely): Gresham, September 15; Spalding, September 24; Chadron, October 1. Kansas (may winter rarely in southern part): Wichita, October 24; Cirnarron, November 30. Oklahoma (may winter rarely): Arnett, October 7; Fort Sil], October 10.

The migration of these owls is perhaps more graphically portrayed by three cases of individuals marked with numbered bands. One was banded at Northville, S. Dak., on July 1, 1931, and recaptured at Royal, Nebr., about October 1, 1931; the second, banded at West Kildonan, Manitoba, on July 31, 1926, was shot at Spalding, Nebr., on September 24, 1927; the third, also banded at Northville, S. Dak., on June 27, 1931, was retaken near Gunter, Tex., on January 7, 1932.

Casual records: On several occasions the burrowing owl has been taken outside of its normal range. Among these are the following: About half a dozen specimens have been taken in Louisiana (Chenier Tigre, March 6, 1918, and December 10, 1925; Grand Isle, one on April22 and two on April 27; Baton Rouge, March 11, 1933). Apparently all these belonged to the western subspecies. A specimen collected on Blakely Island, opposite Mobile, Ala., on February 3,1912, is the Florida race. A specimen was taken in Porter County, md., on April 16, 1924; one was captured alive on Wolfe Island, Ontario, in the fall of 1894; on October 22, 1918, one came on board a naval vessel ofT Hampton Roads, Va.; one was reported from New York City in August 1875; one was collected at Newburyport, Mass., on May 15, 1875; and a specimen was found dead at Dover, N. H., about February 20, 1922.

Probably the most northern occurrence is a nonbrecding male collected on July 8, 1921, ten miles north of Poplar Point, Manitoba.

Egg dates: Florida: 52 records, March 22 to May 21; 26 records, April 4 to 23, indicating the height of the season.

California: 41 records, April 1 to June 17; 21 records, April 14 to May 2.

Colorado and Kansas: 11 records, March 29 to July 1; 6 records, May 14 to June 2.

Dakotas: 7 records, May 1 to June 13.

FLORIDA BURROWING OWL
SPEOTYTO CUNICULARIA FLORIDANA Ridgway
HABITS

Ridgway (1914), although he originally described this owl under the above name, treats it in his latest work as specifically distinct from the western bird, and applies the name Speotyto floridana floridana to the birds of Florida and the Bahamas. He describes it as “above darker and much less buffy brown than in any of the forms of S. cunicularia, with the spotting dull white instead of more or less buffy; ground color of under parts much less buffy (dull white, buffy only on thighs and under wing-coverts); under wing-coverts spotted with brown, at least toward edge of wing; tarsus less extensively feathered, the feathering shorter; wing and tail averaging much shorter than in S. cunicularia hypogaea and bill larger.”

The home of this owl is on the prairies of central and southern Florida. One naturally associates burrowing owls with the western prairies and open plains, and so it is not surprising that these birds are to be found on the wide, open spaces in the flatter portions of Florida. On my first visit to Florida I drove for many miles over the extensive prairies that lie between the marshes of the upper St. Johns River and the east coast and was greatly impressed with their many reminders of the western plains; there was the broad expanse of flat grassland, stretching away nearly to the horizon, where distant clumps of trees suggested the tree-claims or the timber belts along the western streams; only the scattered palmetto hammocks broke the illusion; roving bands of wild cattle, with an occasional picturesque cowboy rounding them up, a stray upland plover, then on its way north, the numerous sloughs and ponds, and frequent glimpses of sandhill cranes, all added to the picture. The great Kissimmee Prairie, which I visited later, furnishes even more congenial homes for burrowing owls and cranes in its vast expanse of flat grassy plains.

Charles J. Pennock, who has had considerable field experience with these owls, has sent me some very elaborate notes on them; as to their haunts, he says: “These almost treeless tracts may vary in size from a few acres to several square miles, may be a disconnected series of open moors or field like tracts, or they may be a chain of larger or smaller prairies, with sloughs, hammocks, or ponds intervening. Wherever found nesting, they are quite sure to be on the higher, drier, opener, and least fertile places. So little above the underground water table is much of the country that these birds frequent that a very short distance, even a few rods, may determine the presence or absence of Speotyto, for, where the ground drops to a depression, a pond may be formed, or, failing that, scrub palmettos or other coarse plants may grow, among which the owls do not find congenial abiding places. Even the presence of an occasionally used roadway across a prairie may make the difference to these birds, and it is quite usual to find them located on the borders of such paths or, as I have seen more than once, their domiciles on the very shoulder of the road, between the side ditch and the wheel track. No doubt such sites mean a drier nursery, for they are not infrequently delayed in their home building by rains in March.”

This would seem to indicate that these owls always select high, dry ground for their nesting sites; but Samuel N. Rhoads (1892) found a large colony in soil that had previously been very wet, “a continuous colony, three miles long, of breeding Owls. The retreating waters of the adjoining slough had left a margin of flat, grass-grown sand, of varying width, between the swamp and the saw palmettoes, and extending indefinitely in the direction of the stream. This formed the breeding ground of several hundred pairs of Owls.”

W. P. Owen writes to me that he and H. H. Bailey have noticed “the moving of the burrowing owl from its accustomed habitat, the golf courses, to the dairy pastures”, in Dade County.

Nesting: Probably no such large colonies as that referred to above exist today. W. J. Hoxie wrote to me of visiting a large deserted colony on the St. Johns Prairie in 1893, where the remains of the old towns were strikingly apparent for miles in groups of from six to twenty on all sides; “the mounds, being constructed of the deeper subsoil, long resisted the encroachment of the vegetation and stood bare and sun scorched.” Mr. Pennock says: “On but one occasion did I find a close community; then there were six or eight pairs nesting on a restricted tract of not exceeding four or five acres. * * * On only a single occasion, did I find these birds occupying a burrow, other than of their own excavation. This burrow, from its location, size, and form, was unquestionably the work, originally, of the highland tortoise or ‘gopher’, so called by the residents.”

Other observers all agree that these owls excavate their own burrows, mainly because the “gophers” are seldom found on the prairies frequented by the owls, and because there are very few burrowing mammals to be found in the same region. Occasionally, a deserted burrow of a fox or a skunk may be occupied, but these are generally in thick cover, which the owls do not like.

Most of the burrows that I have seen have been widely separated, single nests; but once, while hunting with Mr. Pennock in Charlotte County, we found five pairs of owls nesting within the space of a few acres. This was on March 5, 1925, and the owls had not laid in the only burrow we dug out, though the burrow and nesting chamber were apparently finished; the hole ran downward at a sharp angle for 15 or 20 inches, and along at that depth, with one slight turn in it, for about 6 feet. Mr. Pennock says that the burrows vary in length from 5 to 9 feet, and are usually shallower than those of the western burrowing owl, from 14 to 20 inches below the surface of the ground. Sometimes they are quite straight, but often they make one, or rarely two, abrupt turns. He says that sometimes the eggs are placed directly on the bare earth, but usually some material is used as bedding, grass cut to short lengths, rarely some hair or feathers, and once a lot of shredded newspaper; more frequently small pieces of dry horse or cow manure are used, sometimes in considerable quantities; once more than half a peck of finely broken cow manure was taken from one cavity.

Referring to the colony described above, Mr. Rhoads (1892) says:

With three exceptions all of the twenty burrows I explored were dug in the moist, sandy margin of the slough, from twenty to one hundred feet down the gentic, grassy slope between the thickly fringed palmetto bank and the water’s edge. The more recently constructed burrows were invariably nearer the water, owing to the greater ease of digging in the wet sand. In these cases the burrow throughout its entire length would just graze the lower surface of the thin sod, occasionally even penetrating it, causing, in such an event, its abandonment. If not abandoned, one of the myriad roving cattle would be likely soon to set foot on it and break through, or a sudden shower might fill it with water.

Eggs: The Florida burrowing owl lays four to eight eggs, usually five or six. The eggs are indistinguishable from those of the western bird. The measurements of 50 eggs in the United States National Museum average 32.4 by 26.9 millimeters; the eggs showing the four extremes measure 34.3 by 28, 33 by 29, 28.6 by 25.4, and 30.8 by 25 millimeters.

Young: Incubation is shared by both sexes, and probably lasts about three weeks. Mr. Rhoads (1892) says: “The voracity of the young is phenomenal. I kept seven, of different ages, in a tin box for several days. Beside eating everything, fresh or putrid, that was offered, they attacked and devoured each other. I was forced to kill the three remaining cannibals to preserve them.”

Plumages: The plumage changes of the Florida burrowing owl are apparently similar to those of the western bird. Mr. Pennock says, in his notes: “In coloring the adult female is decidedly more rufous on the back than is the male, and the spots on the breast and belly of the male are more sharply defined, rather darker with more distinct margins. This is not often sufficiently pronounced to be apparent in the single bird at rest. In flight, the deeper, brownish tinge on the back of the female will at times, in certain lights, become evident. In a series of birds, with males and females separated, the difference becomes clearly marked.”

Food: According to Mr. Pennock, the food of these owls consists largely of night-flying beetles; “when shot early in the morning, their stomachs are usually well filled with such food. Other food noted was remnants of a crab, a small decapitated snake, and parts of a frog”, found about the entrances to burrows.

Mr. Rhoads (1892) writes:

When the nest contained young, the mound and burrow were strewn with the rejected remains of their food, but, strange to say, there was no evidence that the young or old ejected the pellets so peculiar to rapacious birds. If they had done so we certainly should have found them. Among these remains were detected the legs and elytra of various grasshoppers and coleoptera, skulls of a very small rodent, skulls and backbones of fish, one of which was six inches long, the skins of snakes, the dried body of a lizard, frogs and crayfish, and feathers of four or five species of birds, noticeable among which were those of the Cuban Nighthawk, Bobolink and Savanna Sparrow.

Behavior: Mr. Pennock says: “The flight is more undulating than that of any other bird I know, a series of abrupt, sweeping rises and swinging drops, rarely making a flight of more than 40 or 50 yards, often swinging back to, or near, their home-site, or more frequently dropping down to another burrow entrance, perhaps not over 20 or 80 yards distant.” He thinks that this second burrow may be a haven of refuge in time of trouble, as the owls often have two burrows in use, one for nesting and one for a resting place.

I have always found the Florida burrowing owl rather tame and easily approached; others have had the same experience with it. Once I lay for half an hour within 8 feet of one, as it stood on its mound, preening and oiling its plumage, as a shower was threatening; I even saw it pinch its oil gland; its small bill seemed rather awkward for preening. Although it seemed to be very alert, it paid little attention to me, but kept turning its head quickly in all four directions, looking for prey, two or three times it darted off and caught some insect either on the ground or in the air, giving a little cry as it started; on returning, it spread its feet widely apart and landed on its mound with a little slide. Once it gaped, half closed its eyes, and dozed for a few moments.

As a rule these owls are very gentle, though they will put up quite a fight when handled; but Mr. Rhoads (1892) says: “The anxiety of the old males whose young are being threatened is so great that I have had them strike my cap awry while digging, and in general the conduct of the females in comparison is shameful. * * * Where four or five pairs were living close together the males would combine their attacks upon me and the females would retire together to some secluded spot and have a talk.”

Frederic H. Kennard (1915) writes:

On approaching an inhabited burrow, if one or both of the owners were not already in sight, they very quickly appeared; and standing bolt upright on their little mound of sand at the mouth of the burrow, would courtesy grave]y to me, until on my nearer approach, they would fly off onto the prairie, perhaps fifty or a hundred feet, where they would continue their courtesies, uttering at the same time their calls; Whit, whit-whit, a long and two short notes: or Whit-whit, whowho-who-who-whit, two short notes followed by a stutter, a little lower in tone but ending with a short sharp whit at the end; or Whit-whit, who-who-who-who-who, two short whits, followed by the stutter. Often instead of flying they would run over the prairie, reminding me of the Robins one sees on the lawn, which after standing upright and still, suddenly bend forward and run.

Bendire (1892) says that “after the breeding season is over, the Florida Burrowing Owl is said to disappear for a time from its usual haunts, but where it goes is not positively known.”

Enemies: Bendire quotes J. F. Menge as saying that “many of their nests are yearly destroyed by skunks and opossums, who seem to be very fond of the eggs.” Mr. Hoxie tells me that it has been quite a common practice for the cowboys to shoot these owls, as being detrimental to the cattle business; the only reason for this is that a horse or a cow may occasionally break a leg by stepping into a burrow while running. It would hardly seem that there are enough of the holes to cause much damage in this way, but, sad to relate, any wild creature that interferes in the slightest degree with man’s interests has to be sacrificed.