Chapter XI: Introduction (10)

More instances of climbing, than of swimming, have been reported in the literature for the long-tailed weasel. Seton (1929 (2):625) quotes William M. Graffius of Pennsylvania as having seen a weasel closely pursue a red squirrel nearly to the topmost branch of a large hemlock. When the squirrel loosed its hold and dropped into a stream, the weasel descended to the ground and caught and killed the squirrel when it emerged from the water. Pearce (1937:483), in central New York State, on July 29, 1931, watched a weasel chase a chipmunk up a black cherry tree ten inches in diameter, and noted that the first rush carried the weasel "straight up the trunk for approximately 10 feet, where it hesitated momentarily before continuing. Then, instead of climbing vertically, it made progress by traveling in short ascending spirals around the trunk, scarcely making 3 feet in height for each circuit of the tree. Upon reaching the limb by which the chipmunk escaped, the weasel followed out along this in the same spiral manner. This limb had a diameter of about 4 inches at its base and extended upward at an angle of perhaps 20 degrees above the horizontal . . . it made its way head first almost down to the ground, using the same spiral mode of progress, but at a leisurely pace. . . . While traveling down the side limb it appeared practically to wrap its sinuous body around the limb."

A male long-tailed weasel, from Colorado, which I kept captive was often fed freshly killed mice. These I thrust through one of the small openings in the wire mesh. The weasel quickly learned to seize any part of a mouse thus introduced and his tugging aided in getting the mouse into the cage. Occasionally a mouse too large to be got through the mesh had to be withdrawn. In such an instance, if the weasel had already had hold of the mouse, he would screech frightfully. I have heard no other vocal sounds from a weasel except a kind of purring.

The sense of smell apparently is well developed; at any rate it is keen enough to allow the weasel to follow the trail of an intended victim by the scent left by the latter. Murie's (1935:321-322) account, for example, of a weasel pursuing a snowshoe rabbit gives clear evidence that the weasel relied on scent in following the rabbit.

A captive male weasel obtained at Gainesville, Florida, stamped his hind feet when annoyed (Moore, 1945:259).

A male from Colorado that I kept for months in a cage at Lafayette, California, was several times found in a sleep so deep that he was awakened with difficulty. Seton (1929 (2):629-630) writes: "In my small menagerie, I have had half-a-dozen Weasels of the New York species. Their sleeping dens are arranged so as to be easily and silently opened. Several times I have lifted the lid to find the weasel in a deep sleep--a sleep so profound that I had to poke him vigorously with a stick before he awoke, looked up, and rushed forth with a little puff of wrath, and a little puff of smell."

Feces and urine were ordinarily deposited in one particular place by each of the captive weasels that I have observed. Hamilton (1933:294) records that a large male _M. f. noveboracensis_, in a week, averaged 10 evacuations every twenty-four hours, that urination immediately precedes defecation, and describes the feces as black or brown, long and narrow and often spiral-shaped owing "to the matted fur of some rodent that had been eaten." Quick (1944:77) writes, concerning four winter dens in Michigan, that "The latrines of weasels were in the entries of used dens and scats could be collected there by the handful." Polderboer, Kuhn and Hendrickson (1941:116) in the spring of 1939 at Ames, Iowa, gathered scats "from latrines found at the entrances of burrows and from latrine chambers found within burrows." Scats were found by them in the linings of some nests.

Courage of a high order might be credited to the long-tailed weasel because individuals have attacked animals much larger than the weasels. Actually, however, in few if any of these instances was the motive for attack known. That a hawk was attacked is suggested by Soper's (1919:45) account of _Mustela frenata noveboracensis_ wherein he repeats a story told to him of a hawk observed in unsteady flight, and obviously in distress, which when it plummeted to earth was with a weasel which escaped from the observer. Charles Tatham, Jr., of Cambridge, Massachusetts, according to Seton (1929 (2): 630, 631) observed one that attacked his dog.

Persons and long-tailed weasels have figured in some rather strange encounters. For example, Oehler (1944:198) recounts that in the autumn of 1940 at Cincinnati, Ohio, an animal, mistakenly thought to be a chipmunk, was seen to dash into a hollow log whereupon pounding on the log brought out the weasel which bit and clung to the hand of one man whose companion was bitten when he attempted to free the man that was bitten first.

Seton (1929 (2): 631) writes that on the night of September 5, 1897, on Roosevelt's old ranch, near Medora, North Dakota, a man turned over his saddle (which was lying on the ground) to dislodge what was thought to be a pack-rat. The animal was a long-tailed weasel which attacked him. It ran up his legs a number of times aiming at his throat before being killed by a dog.

Criddle and Criddle (1925:146) wrote: "August 20, 1919.--A _longicauda_ in the Insectary ran at me this morning apparently with a view to intimidating. It uttered a shrill cry while making the attack, but retreated after advancing within two feet." The same authors (_op. cit._: 147) further write that a "Long-tailed Weasel was caught in a trap set for gophers, and, on being released by Miss M. Criddle, at once turned upon its liberator and bit savagely at her boot. It then moved a short distance away to a tub of water, where it drank thirstily, merely glancing at the observer from time to time while doing so, and then ran off out of sight.

"Mr. T. Criddle records a similar experience. After liberating a large weasel from a trap, it immediately rushed at him and persisted in its attack with such ferocity that it was three times picked up and thrown, on each occasion to a greater distance, before it finally abandoned its offensive.

"We have no record of a weasel making an unprovoked attack upon anyone."

Wight (1932: 164) in Michigan, detected a weasel attacking a hen. The weasel fled at Wight's approach but returned and attacked him several times. Finally the weasel went around Wight to reach the hen. In Wight's words "There was no evidence of infuriation, but rather a well directed offense at the one object, regardless of its size, which stood between the weasel and an opportunity to satisfy its desire to kill, which was probably based upon the uncontrollable urge of hunger pangs."

Weasels of each of the three North American species have been successfully kept in captivity. A type of cage satisfactory for keeping the animals in the laboratory is described by Bissonnette and Bailey (1940:761-763). Some of the captives used their teeth to break glass water-containers and to gnaw slivers of wood from the cages. Ingested slivers of wood and bits of broken glass caused the deaths of some of the captives. Weasels kept by me all were of the species _Mustela frenata_. They thrived on a meat diet but I was always careful to give them, every few days, if not each day, some small rodents entire, thinking that the bits of bone and fur ingested might, in some way unknown to me, keep the digestive tract in better condition than would flesh devoid of hair and bone.

Three young weasels approximately the size of mice, in the Okefinokee Swamp of Georgia, were obtained by a hunter who, according to Harper (1927:303), raised them by feeding "milk for a few days, and then fresh meat." Litters of young born in captivity have been successfully raised by the mothers (Hamilton, 1933) and success in getting the animals to breed in captivity and to rear their young is recorded by Wright (1948A). He has found, however, that the majority of his captive adult males show no interest in mating when placed with females in heat. He, therefore, uses only selected males and when a female in heat is to be bred, he places one of his responsive males with her one day, another of his responsive males with her the second day and thus alternates a couple of males for three or four days. Even so, slightly fewer than half of the females which were thus bred produced young.

A weasel in the white winter coat was used by Audubon and Bachman (1856:177, Quarto edit.) to drive rabbits out of their burrows in the same fashion that ferrets commonly are used. Although these naturalists refer to their animal as an ermine it probably was _Mustela frenata noveboracensis_, the long-tailed weasel. The animal's teeth (probably canines) were blunted and a long cord tied on its neck. With the aid of this weasel 12 rabbits were caught in one morning and more than 50 in four weeks.

Enemies

Little is recorded concerning enemies of weasels and it may be that other vertebrates are not an important factor in removing the annual increase. Errington (1935:195-198), in Iowa, found four, putrid weasels about dens of red foxes, _Vulpes fulvus_. No remains of weasels were found in the feces of the foxes and it appears that the foxes do not eat the weasels. The label on an adult female specimen of _M. f. spadix_ from Boone County, Iowa, bears the date May 10, 1938, and the annotation, by T. G. Scott, "fox-killed." Bailey (1931:328) recounts that "Weller saw a coyote carrying one in its mouth" at an elevation of 11,500 feet in the Pecos Mountains of New Mexico. The type specimen, a young female, of _M. f. peninsulae_ from Hudsons, Florida, according to Rhoads (1894:155) ". . . was caught in the woods by a cat." Barber and Cockerell (1898:189) mention one that was killed by a dog in Mesilla Park, New Mexico. Moore (1945:258) records the death of a weasel in Florida. Circumstantial evidence indicated that it was killed by the bite of a water moccasin. In the Biological Surveys Collection of mammals in the United States National Museum, the label with the skull of an adult male weasel, No. 160663, from Banning, California, carries the information that the skull was taken from the stomach of a _Crotalus_ (rattlesnake).

In reporting on a study of owl predation in Delaware County, Pennsylvania, Pearson and Pearson (1947:143) mention that "weasels are found throughout the county but . . . were never eaten by the owls."

The Uinta spermophile at some places and times probably is a prey sought by the long-tailed weasel but Warren (1924:265) records _Citellus armatus_ repeatedly chasing weasels in August, at Camp Roosevelt, Yellowstone National Park, and how the ground squirrels at one time ignored the weasel even when it came within a few inches of a squirrel.

Warren (1932:71), on August 2, 1931, at Grand Mesa, Colorado, obtained a large male weasel with two porcupine quills in it; one was near the mouth and another "in the skull." Osgood (1935:156) writes that near Rutland, Vermont, a male weasel "taken in April, was heavily parasitized and had several short porcupine quills embedded in its neck, head, and shoulders." The remainder of Osgood's account implies that the weasel may have turned to porcupine because the normal food for weasels was scarce at the time. Porcupine quills, then, are a hazard for weasels although it is unlikely that the porcupine is ever to be classed as an enemy of the weasel.

An accident of another sort, which must at the very least have been annoying to the weasel that suffered it, was recorded by Soper (1921:37). The animal had a stick lodged crosswise between the fourth upper premolar teeth.

The recorded actions of several kinds of animals which are too small to be dangerous to the weasel suggest that they recognize that the weasel is a danger to them. Borell and Ellis (1934:21) mention that a weasel in Nevada caused a great disturbance among the chipmunks. Long (1938:250) heard pikas give evidence of terror by a peculiar cry when a weasel was in a rock slide occupied by the pikas. Seton (1929 (2):629) writes "On June 14, 1915, as I prowled around the south side of the lake on my homeland at Greenwich, Conn., my attention was called to a pair of song sparrows and a male towhee that were noisily mobbing a Weasel, twittering around and darting at him, as though they knew full well his evil ways. The weasel paid little heed, but soon dived from sight in a stone wall."

No account has been found of an American weasel or ermine rolling, tumbling and frolicking in a manner that aroused the curiosity of birds to a degree which permitted the weasel to come within leaping distance of the birds. Accounts of such behavior are on record for the English stoat (ermine).

Food and Hunting

Weasels are active both in the daytime and at night. Whether the time of activity varies with the season, with the locality, with the sex or with other conditions, I do not know. Adult, live, free-living, actively moving weasels that I recall having seen all were observed in the daytime: two were in Alameda County, California, two were in White Pine County, Nevada, one was in Scotts Bluff County, Nebraska, and one was in Laramie County, Wyoming. I recall ten adults, from the same three states, and one from Washington State, that got into my traps; two of these certainly got in the traps in the night; one certainly got in the trap in the daytime; the other eight were found in traps which may have caught the weasels either in the night or in the daytime. Soper (1946:136) in speaking of _M. f. longicauda_ north of the International Boundary in Canada remarks that it has the "habit to some extent of hunting at all times of day." Criddle and Criddle (1925:144) in writing of _Mustela frenata longicauda_ in Manitoba record that "The shrill cry of a rabbit [_Lepus americanus_] in the dark is nearly always due to the weasel's attack. Indeed, we have often watched the latter at work during the twilight hours. First would come the almost noiseless run of the small rabbit with its characteristic dodging and this would be followed by the appearance of the agile foe which, at times, would leap high over obstacles and at others move swiftly beneath them. Then there would follow intermittent cries of the rabbit as the weasel secured a temporary hold of its quarry, for be it noted that this hunter apparently bites anywhere to begin with and it is probable that the blood made to flow acts as an aid to tracking as well as weakening the prey. Several similar close encounters might occur before the rabbit would be finally overcome, but weasels are very persistent when they once get into contact with their victims and it is therefore very seldom that the latter escape. In killing, they either penetrate the brain with their teeth, or dislodge the vertebrae behind the head." These and more than two score other observations which record the time when weasels were seen make it clear that some were active at night and that some were active in the daytime.

As to the routes traveled while the weasels are hunting, Quick (1944:77) says of four individuals that he studied in Washtenaw County, Michigan: "The weasels appeared to prefer hunting certain coverts with noticeable regularity, but rarely cruised the same area on two consecutive nights."

The killing technique of fifteen captive _Mustela frenata noveboracensis_ was studied by Glover (1943A). For the weasels he released 19 mice, 3 brown rats, 6 cottontails and 4 ring-necked pheasants. Most of the mice were killed by a bite on the back of the head, with the body and legs of the weasel hugging the back of the victim. "The weasel shoved the prey in close to the stomach with the hind legs, and the kill was made in a reclining semi-curled-up position." On each of the rats (_Rattus_) an initial grip was secured at the base of the ear. When the rat rested, a new hold was taken by the weasel. Finally the weasel secured a hold at the base of the skull and near the ear, and a light crushing sound followed. Four of the six cottontails were killed by bites on top of the head and ear; two cottontails succumbed from neck wounds. In three instances, neither of two weasels could be induced to make a determined attack on the cottontails or to kill them. At times the cottontails proved to be able opponents for weasels by striking out with their front feet and by kicking with their strong hind legs. In killing the pheasants the teeth of the upper jaw of the weasel pierced the top of the braincase and the teeth of the lower jaw entered the region of the auditory process. The forelegs hugged the neck of the pheasant, the body of the weasel was extended in a riding position on the back of the bird and no amount of kicking or rolling dislodged the weasel.

Polderboer, Kuhn and Hendrickson (1941) describe a cottontail cached by a weasel as having the muscles of the neck severed from the region behind the right mastoid process and noted "that hemorrhage in the region of the right jugular vein had occurred."

Concerning the methods of killing mammals smaller than cottontails, the accounts by Nichols and Nichols (1935:297-299) and that by Svihla (1931) corroborate Glover's (1943A) account, as do also the accounts of Miller (1931B:164) and Moore (1945:257). The latter says that his captive male, from Gainesville, Florida, customarily bit its rodent prey at the base of the skull and used the feet to manipulate the live prey. Miller (_loc. cit._) emphasized that his male weasel (_M. f. longicauda_) grasped where it could, used its snakelike body to coil over the prey and shifted the grip of its teeth to the nape of the neck or back of the skull. The captives that I have had [one from Salt Lake City, Utah; three from Contra Costa County, California; and the same individual reported upon by Miller (1931:150)] customarily employed the techniques of killing small rodents that were described by Glover and Miller (_loc. cit._).

Allen (1938:225-229) experimented with the ability of four different males of _M. f. noveboracensis_ from Michigan to kill adult cottontails. The method used was to place the weasel in a cage of quarter-inch hardware cloth approximately three feet long, two feet wide, and two feet high. The bottom of the box was covered with several inches of straw. One cottontail was offered to each weasel. In two instances the weasel attacked and bit the cottontail, was struck by the hind feet of the cottontail, retired from the attack and died a few hours later as a result of the blows of the cottontail's hind feet. In the other two instances the weasel rendered the cottontail helpless by severing the neck muscles from the skull. Subsequently an incision made by the weasel, in each of the two instances gave access to blood on which the weasel fed until it was full, in one instance by licking "blood as a cat laps milk." One rabbit was subdued in 10 minutes and the other in 15 minutes. Allen (_op. cit._) points out that cottontails form a considerable portion of the weasel's food and thinks that they are killed in burrows more easily than they were in the cage.

In writing of the three species of weasels, including _Mustela frenata_, found at Treesbank and vicinity, Manitoba, Norman Criddle and Stuart Criddle (1925:143, 144), in my opinion, correctly explain the killing of more prey than weasels need. "The fact that weasels frequently kill many more animals than they require for immediate use has been universally interpreted as a lust for killing--a supposition which we believe to be quite erroneous. It is true that weasels often kill more than they need, but the surplus is not necessarily wasted because the animals always store it for future use, in much the same way as do badgers, minks or skunks, and with the same object in view as squirrels have in gathering nuts. We have observed many such stores, but as far as our observations go, the habit of killing in excess occurs much more prominently in the late summer and autumn months than in the spring. Indeed, we have no records of excessive spring slaughter and this indicates that the supposedly blood-thirsty habit of weasels is no more a lust for killing than is the woodsman's foresight in providing his larder with meat for the winter months. It should be noted in this connection that members of the weasel family, when undisturbed, do not leave their victims scattered about, but carefully store them away, and in many instances the bodies are buried with earth or taken under ground to preserve them. We suspect that this instinct for preserving food for future use accounts for most of the excessive killing by carnivorous animals instead of this latter indicating an aimless desire for slaughter which would unnecessarily deplete the food supply of the future. This instinct, however, does not seem to be as definite as that of some rodents, and there is no doubt that much of the stored meat decays before it can be utilized."

Criddle and Criddle (1925:146) note that a weasel in the vicinity of Treesbank was carrying a rat [_Rattus_] and that "Two small punctures in the throat were the only evidence of the manner in which its death had been brought about."

Considerable information has been recorded concerning the food of _Mustela frenata_ and a little information is on record as to kinds of foods not taken that could have been taken. For example, Ingles (1939:253, 254) on May 14, 1938, near Shasta City, California, noted that nestlings of russet-backed thrushes were ignored by an adult weasel and four young weasels which were feeding instead on meadow mice and a mole. Howard (1935:322, 323) records that a weasel in Michigan which carried bits of meat from beef bones on a porch ignored a red squirrel which drew on the same food supply but which retreated to the end of the porch when the weasel appeared. Quick (1944) records that in the winter of 1940 on a 640 acre area in Washtenaw County, Michigan, four resident weasels did not kill any of the 10 rabbits or several pheasants but subsisted on smaller animals. Glover (1943A) thought that _M. frenata_ kills only a few adult cottontails in the wild. To judge from these observations, _M. frenata_ chooses small mammals as prey in greater measure than it does birds or larger mammals.

Records of prey taken, attacked or pursued by _Mustela frenata_ include the following:

Broad-footed mole (_Scapanus latimanus_).--One was fed on by an adult _M. frenata_ and four young, on May 14, 1939, "near Shasta City," California (Ingles, 1939:253, 254).

Dusky shrew (_Sorex cinereus_).--A female weasel, at Majestic, Long Island, N. Y., was shot when carrying a _Sorex cinereus_ that had a small hole in the top of its head (Nichols and Nichols, 1935:297-299).

Big short-tailed shrew (_Blarina brevicauda_).--One was taken from the stomach of a weasel (Hamilton, 1928:249).

Townsend ground squirrel (_Citellus townsendii_).--Alcorn saw a weasel five miles west of Fallon, Nevada, carrying a squirrel (Hall, 1946:192).

Richardson ground squirrel (_Citellus richardsonii_).--The attempted capture of one of these squirrels in Saskatchewan is recorded by Seton (1929 (2):625).

Belding ground squirrel (_Citellus beldingi_).--Grinnell, Dixon and Linsdale (1937:233) recount that at Tuolumne Meadows, California, a weasel killed a ground squirrel of this species.

Thirteen-lined ground squirrel (_Citellus tridecemlineatus_).--Errington (1936:406, 407) found a den in Palo Alto County, Iowa, on June 22, 1934, where he collected 32 fecal pellets. Sixteen samples contained thirteen-lined ground squirrels, 9 contained rabbits, 9 contained mice (7 _Microtus_, 1 _Peromyscus_ and 1 unidentified); red-winged blackbirds and unidentified fringillids were represented as also were ground beetles, grasshoppers and other insects. One red-winged blackbird lay near the entrance of the den.

Franklin ground squirrel (_Citellus franklinii_).--Sowls (1948:126) records that at Delta, Manitoba, a weasel was observed killing one of these squirrels and that "the weasel had taken the squirrel from its hibernating burrow as evidenced by tracks in the snow." On July 19, 1917, in the vicinity of Treesbank, Manitoba, T. Criddle saw a weasel attacking one of these ground squirrels which was in mortal terror and squeaking continuously. Eventually the squirrel was thrown on its back "and would have been speedily killed but for an interruption" (Criddle and Criddle, 1925:146).

Golden-mantled ground squirrel (_Citellus lateralis_).--On August 15, 1941, along the Kaweah River in Sequoia National Park, Boyer (1943:99, 100) saw a weasel chasing a _Citellus lateralis_; three or four times the weasel grasped the back of the neck of the squirrel which each time threw off the weasel until the two, weasel after the squirrel, plunged into the river. The squirrel, bleeding at the base of the skull, was rescued and entered a hole; the weasel got out of the water and under a rotting log. Follett (1937:365) at 2 p.m. in Plumas County, California, saw a weasel have hold of the lower jaw of a golden-mantled ground squirrel near its throat. Alcorn watched a weasel chase a golden-mantled ground squirrel in Nevada (Hall, 1946:192) and Grinnell and Dixon (1919:681) record that on August 4, 1911, near Monache Meadows in eastern Tulare County, California, a weasel pursued, captured and killed a golden-mantled ground squirrel.

Eastern chipmunk (_Tamias striatus_).--Pearce (1937:483) in central New York State, on July 29, 1931, saw a chipmunk scamper up a tree pursued by a weasel.

Chipmunk (subgenus _Neotamias_).--Stanford (1931:363) on November 11, 1931, at Fish Lake, Utah, saw a weasel pursuing a chipmunk. On August 5, 1910, "near Independence Lake," Nevada County, California, Louise Kellogg recorded that a weasel seized and ran off with a chipmunk (Grinnell, Dixon and Linsdale, 1937:233). Allen (1938:228) observed that a chipmunk (whether _Tamias striatus_ or _T. minimus_ not specified) was killed in 30 seconds whereas 10 to 15 minutes were required by the caged, male _Mustela frenata noveboracensis_ to kill a cottontail.

Red squirrel (_Tamiasciurus_).--Seton (1929 (2):625) records the capture of one in Pennsylvania, and Grinnell, Dixon and Linsdale (1937:232), at Cisco, California, saw one closely pursued by a weasel.

Flying squirrel (_Glaucomys_).--Burroughs (1900:77, 78) records remains of one of these squirrels along with the remains of other animals in a food cache of a Mustela but his account does not make clear whether _Mustela frenata_ or _Mustela erminea_ was the species of weasel involved.

Northern pocket gopher (_Thomomys_).--In "July, 1939, near Stillwater [Nevada], Alcorn pursued . . . [a] weasel and caused it to drop . . . a pocket gopher [_Thomomys bottae_] which was about two-thirds grown" (Hall, 1946:192). Grinnell, Dixon and Linsdale (1937:233) write that "at least twice, weasels in the [Yosemite] Valley were seen carrying pocket gophers." Relative to _Thomomys talpoides_ in the vicinity of Treesbank, Manitoba, Criddle and Criddle (1925:146) record that on September 11, 1918, an individual of _Mustela frenata longicauda_ took seven pocket gophers dead. . . . It seized the rodents by the middle of their back and held them high while carrying them away. They were stored in a gopher burrow some two hundred yards distant. On February 17, 1921, "Came across the marks of a weasel carting some object over the snow. An investigation revealed a recently-killed pocket gopher with its captor still in possession." Criddle (1930:279), at Aweme, Manitoba, "frequently observed this weasel [_M. f. longicauda_] . . . carrying a pocket gopher to its larder, and twice it has been encountered in mid winter with freshly killed gophers in its possession." The evidence already presented that weasels levy heavily on pocket gophers is strengthened by the many references in the literature to weasels having been caught in traps set for pocket gophers in the burrows of those rodents and by the many statements, not quoted here, that living quarters of weasels are in burrows made originally by pocket gophers. For example, the present writer, in an account of the Mammals of Nevada (Hall, 1946:191, 192), has said of the long-tailed weasel, _Mustela frenata nevadensis_, that "All the three dens that were excavated . . . were originally burrows of pocket gophers. . . . Although we have found weasels in many situations in Nevada, . . . they most often were obtained from the burrows of pocket gophers." Excluding the weasels taken by Alcorn, more specimens of the remaining lot were caught in traps set in the burrows of pocket gophers than by all other means combined. All of the 22 weasels taken by Alcorn [within a radius of 10 miles of Fallon] were obtained in gopher traps.

Mexican pocket gopher (_Cratogeomys_).--At Chalchicomula, 8000 feet, Puebla, Nelson (1918:470 and letter dated March 9, 1928) saw a weasel fastened to a pocket gopher. Nelson obtained the pocket gopher and found that its neck muscles were torn loose from the skull.

Grasshopper mouse (_Onychomys_).--Barber and Cockerell (1898:189) found remains of this mouse in the stomach of a weasel at Mesilla Park, New Mexico.

White-footed mice (_Peromyscus_).--Green (1936) saw a weasel in Gratiot County, Michigan, in May, carrying a _Peromyscus_. Quick (1944:76), in winter, in Michigan, found one dead, probably killed by a weasel. From Washtenaw County, Michigan, Quick (1944:77) examined 294 scats of free-living weasels and found _Peromyscus_ in 189 scats, _Microtus_ in 83, small birds in 20, red squirrel in 3, and hair of weasels in small quantities (probably from the animals which deposited the scats) in 36. He concludes (_op. cit._, 78) that the winter food was 65 to 70 per cent _Peromyscus_, 23 to 33 per cent _Microtus_, and 2 to 7 per cent small birds.

Wood rats (_Neotoma_).--A female long-tailed weasel weighing 250 grams was taken one mile north of Kent, Texas, while eating a _Neotoma albigula_ (Davis and Robertson, 1944:263). A wood rat house under observation by Vestal (1937:364) in Contra Costa County, California, was invaded by one weasel which ate two adult wood rats (_Neotoma fuscipes_) and one young. In the same area he saw a weasel in a wood rat nest some months later (Vestal, 1938:5). Three miles east of Reno, Nevada, on May 13, 1936, W. B. Richardson watched a long-tailed weasel carrying a half-grown round-tailed wood rat (_Neotoma lepida_) across a rock slide (Hall, 1946, 192). Harper (1927:303) records three wood rats [_Neotoma floridana_] and two cotton rats [_Sigmodon hispidus_] found dead in the den of a female weasel and her three young in the Okefinokee Swamp of Georgia. Another female and three young approximately half grown were found in the swamp in a hollow pine log. Contents of the den as described to Harper were nearly a peck of wood rats, whole and in pieces; remains of several kinds of birds including robins and quail, and a piece of joint snake (_Ophisaurus ventralis_).

Meadow mice (_Microtus_).--Polderboer, Kuhn and Hendrickson (1941), in 1939, at Ames, Iowa, identified "A total of 118 items . . . in 97 winter scats and 48 in the 38 spring scats." Their combined data are as follows:

Frequency Percentage
Meadow mouse 71 42.85
Harvest mouse 36 21.75
Deer mouse 17 10.23
Mearns cottontail 14 8.42
Short-tailed shrew 9 5.42
House mouse 3 1.86
Tree sparrow 2 1.02
Grasshopper 1 .60
Shaw pocket gopher 1 .60
Least weasel 9 5.40
Unidentified material 3 1.85

Polderboer, Kuhn and Hendrickson divide their data into two categories, winter and spring. Items recorded in winter but not in spring are house mouse, tree sparrow, and grasshopper. Items recorded only in spring were pocket gopher and least weasel. The samples of cottontail and least weasel all were from the scats of one large male weasel. Of a total of 14 pheasants, 24 quail and 35 cottontails on the 160 acres involved in the study only two cottontails appear to have been killed by the weasels--really by one weasel of four which lived on the area.

Food items taken from the nests (3) and adjacent caches of food in the dens, were as follows: meadow mouse, 30; short-tailed shrew, 4; pocket gopher, 2; deer mouse, 2; least weasel, 1; tree sparrow, 1. The authors remark that the abundance of several prey species does not cause the weasels to ignore the shrews which are said to be distasteful to carnivores.

Two horned larks, apparently killed by weasels, were found on the 160 acre area studied; the horned larks were not in caches of food, nor were remains of horned larks found in scats.

Dearborn (1932:34, 37) for Michigan, on the basis of contents of (37?) intestinal tracts and "feces collected partly in winter and partly in summer" found that, by frequency of occurrence, mammals comprised 83 per cent of the food, birds 10 per cent and insects 7 per cent. Frequency indices for the genera of mammals in percentages of food items of all kinds were as follows: _Microtus_, 31 per cent; _Peromyscus_, 24 per cent; _Sylvilagus_, 14 per cent; _Sorex_, 7 per cent; _Blarina_, 5 per cent; _Scalopus_, 2 per cent.

Criddle and Criddle (1925:146), for the vicinity of Treesbank, Manitoba, record that on October 3, 1913, a weasel was seen to take a field mouse down a hole. They add (_op. cit._: 147) that "Once while ploughing, we observed a Long-tailed Weasel carrying a field mouse. . . ." Ingles (1939:253, 254), in June, 1938, near Mt. Shasta City, California, found an adult and four young weasels which fed on several _Microtus montanus montanus_. Green (1936) in May, in Gratiot County, Michigan, in the vicinity of a nest in which there were four young weasels, found "several" dead _Microtus_. Hamilton (1933:330) records that in New York State a male weasel, on April 5, 1932, at Ithaca, had eaten a _Microtus_ and that in May, 1927, a female weasel was seen carrying a _Microtus_ in its mouth.

Hamilton's (1933:333) study of the contents of the digestive tracts of bodies of weasels obtained from fur trappers and fur buyers enabled him to publish the following "Frequency Indices of Mammal Genera in Fall and Winter Food of 163 _Mustela noveboracensis_": _Microtus_, 33.6 per cent; _Sylvilagus_, 17.3; mammals undetermined to genus but principally mice, 17.1; _Peromyscus_, 11.3; _Rattus_, 9.1; _Blarina_, 5.9; _Sciurus_, 2.7; _Tamias_, 1.0; _Condylura_, 0.8; _Ondatra_, 0.8.

Grinnell, Dixon and Linsdale (1937:233, 234) quote W. Fry concerning a weasel which reared six young at Giant Forest, California, in 1919, as follows: "This parent weasel, after the birth of her young, remained at the premises for a period of thirty-seven days; during which time, from actual count, the following numbers of mammal species fell victim to her: mice [genera not specified] 78; gophers 27; moles 2; chipmunks 34; wood rats 3; ground squirrels 4. This is a total of 148 animals for the . . . thirty-seven days . . . not a bird was captured during the period."

Rats (_Rattus_).--Criddle and Criddle (1925:146), on the farm at Treesbank, Manitoba, record a long-tailed weasel, on July 2, 1918, running away from the farm buildings carrying a rat; July 11, 1919, "Two _longicaudas_ . . . have been seen running off with rats on several occasions."; July 11, 1920, "There are two large weasels about the buildings[;]. . . . Each has been noted with rats and this afternoon one of them was seen running into the woods carrying a rat, followed by two excited swallows." The authors (_op. cit._:147) add "In the fall of 1924, Mr. A. Cooper, a prominent poultryman of Treesbank, observed a large weasel carrying a freshly killed rat which it stored below ground and then returned towards the poultry-house, causing no little apprehension to the owner. Within a short time, however, the weasel reappeared with another rat which it hid as before. In this way several rodents were accounted for during the afternoon, and Mr. Cooper assures us that the weasel 'kept up the good work for some days'." Hamilton (1933:330) in New York State in May, 1927, saw a male weasel in possession of a rat.

Big jumping mouse (_Zapus major_).--In the Warner Mountains of California, on Parker Creek, H. C. Bryant frightened a weasel that dropped a freshly killed jumping mouse (Grinnell, Dixon and Linsdale, 1937:232).

Snowshoe rabbit (_Lepus americanus_).--Adolph Murie (1935:321-322) writes that: "Four miles north of Funkley, Minnesota, early on the morning of November 13, 1921, . . . watched from the top of a 30-foot spruce a weasel. .. hunting a varying hare. . . . The ground was covered with six inches of fresh snow . . . both animals . . . [had] their [white] winter pelage.

"My attention was first attracted to the hare as it came hopping steadily but unhurriedly from the north. Directly in front of me, about 75 feet from the tree I had climbed, the hare crisscrossed back and forth at various angles over an open area about 20 feet in diameter. After producing a maze of tracks, the hare 'froze' near one edge of the pattern. In a few minutes the weasel appeared, all his faculties focused on the warm trail. Expertly he followed its convolutions, passing at times within a few feet of the watching hare. Not until the weasel had followed every turn of the trail to within three feet of its termination did the hare skip off. It came out to the road almost directly below me, turned at right angles northward and was soon out of sight. At the road the weasel lost the trail, . . . and then ran parallel with it, once more in hot pursuit.

"Ten minutes later the hare emerged from the north as before, came on directly to the tracked-up area, and continuing its stratagem, leisurely hopped about to leave its zigzag trail. Then it sat down quietly to wait. . . . The weasel['s] . . . nose led him through the network with little trouble. He was almost upon the hare before it jumped off and followed the same path [as] . . . before. . . .

"The hare had to show his big heels [a third time] . . . as the weasel approached him. This time the weasel failed to follow. . . . After examining a few brush heaps he vanished into the woods behind me."

Seton (1929 (4):723, 724) writes that in December of 1886 in the sandhills northeast of Carberry, Manitoba, he saw a weasel chasing a snowshoe rabbit which took refuge near his feet under the sleigh and so escaped the weasel. Thurber (1940:356) mentions a month-old varying hare that was rescued from a weasel and of approximately the same size as the weasel.

Criddle and Criddle (1925:146) for the vicinity of Treesbank, Manitoba, record "August 21, 1921.--Heard cries of a small rabbit at dusk to-night, which investigation showed was being attacked by a large weasel. The rabbit was later carried to the weasel's store chamber below ground." They record further (_op. cit._, 146, 147): "November 8, 1924.--Shot a bush rabbit and left it lying. Two hours later [it] . . . was found to have been dragged beneath a brush pile and partly eaten. Innumerable weasel tracks left no doubt as to the identity of the thief." In describing a weasel that wintered in a nest in a threshing machine, the same authors (_op. cit._:143) say that no bird remains were found in the pile of approximately three pounds of droppings adjacent to the nest. In a store chamber some 140 yards away from the nest, two bush rabbits (_Lepus americanus_) had been dragged to the entrance and numerous smaller rodents were taken below ground. The rabbits were buried beneath the snow and eaten as necessity arose. Narrow selectivity on the part of the weasel in choosing food is almost always shown in instances where the food of weasels has been studied. For example, the weasel which lived in the threshing machine ate rodents and rabbits and not poultry although the weasel had ready access to the poultry building. The weasel which lived in the bag of feathers in the basement of Stuart Criddle's house ignored grouse, approximately 20 in number, in favor of other non-avian food.

Cottontail (_Sylvilagus_).--Polderboer, Kuhn and Hendrickson (1941) mention that one of 4 weasels which they studied on a 160 acre area at Ames, Iowa, in 1939, had a cache of food in a pocket gopher burrow 10 rods distant from the weasel's den. The cache contained only two cottontails, one partly eaten. Leopold (1937) records seeing a _Mustela_ (probably a long-tailed weasel but possibly an ermine) kill a third-grown cottontail by biting it at the base of the skull. Leopold describes the blood sucking or licking, suggesting that he shared the popular misconception that weasels suck blood. The supposition that weasels suck blood has been refuted by many observers, for example by Svihla (1931). My own observation of captives makes me think that weasels do not suck blood. Seton (1929 (2):626) quotes B. H. Warren as seeing a weasel dragging a freshly killed, still warm, rabbit that contained nine embryos almost ready for birth. A young rabbit was seen being carried by a weasel in Hidalgo County, Texas, in March, 1935 (Mulaik, 1938:104). An instance of a cottontail being chased in June in South Carolina is recorded by Hamilton (1933:330). Addy (1939:372, 373), in Virginia, on August 14, 1939, shot a large weasel which was pursuing a _Sylvilagus_ that was only a foot and a half ahead of the weasel. The rabbit stopped when a shot was fired and permitted itself to be stroked and petted. Tracking showed that the weasel had chased the rabbit for a half mile. On November 20, 1942, at Lake James, Indiana, a weasel was seen by Grosjean (1942:443) attacking a "young rabbit" in the throat of which the weasel had made five large holes from which there was no obvious bleeding. Seton (1929 (4):798) recounts that in 1910 at Base Lake, Michigan, F. C. Hicks saw a cottontail with a weasel hanging to its legs rush to the cottage. When only four feet from Hicks the weasel loosed its hold and the cottontail escaped under the cottage. Burroughs (1939:253) on May 14, 1939, in Saginaw County, Michigan, records that a young cottontail weighing between 200 and 250 grams was carried from the nest and killed. Burroughs was attracted first by the "hissing scream" of the weasel, strode toward the sound, flushed an adult cottontail, and discovered the empty nest from which the weasel had taken the young cottontail.

Brush rabbit (_Sylvilagus bachmani_).--Vestal (1937:364) in Contra Costa County, California, found a brush rabbit that appeared to have been killed by a weasel.

Reptiles.--Grinnell, Dixon and Linsdale (1937:234) recount that in July, 1889, in Wilson Canyon, near Pasadena, California, a weasel killed a red racer by severing the backbone of the snake. In April, 1935, in Hidalgo County, Texas, a half grown bull snake (_Pituophis sayi sayi_) was regurgitated by a young weasel. Russell (1930:504, 505) has recorded finding in California a male weasel and a king snake (Lampropeltis getulus boylii) three feet five inches long in mortal combat. The weasel killed the snake but the weasel, incapacitated by the conflict, was easily picked up by hand and was also saved as a specimen.

Wild birds.--In the spring of 1940, in Washtenaw County, Michigan, one bobwhite, of 10 bobwhite living on a 640 acre area, was killed by one of four weasels that lived on the area. No other quail was killed there. The one unfortunate bird was killed in the mouth of an abandoned den where the quail roosted (Quick, 1944:76). A male weasel, subspecies _M. f. effera_, was seen by Booth (1946:439) attempting to enter the nesting hole of a pair of flickers, _Colaptes_. One song sparrow (_Melospiza melodia_), and one slate-colored junco (_Junco hyemalis_) were recorded by Quick (1944:76) as killed by weasel in Michigan.

Chicken (genus _Gallus_).--Quick (1944:78) writes that in one year (1938-1939) weasels were reported to have killed 1.03 per cent of all chickens in one township of Washtenaw County, Michigan, and that of the total damage to all kinds of poultry, 59 per cent was done by weasels. Weasels entered 19 per cent of the chicken coops on the study area. Farmers killed 68 per cent of the weasels seen in barn yards. Spring and summer were the seasons in which most of the weasels were observed in barn yards. Internal evidence in Quick's (_op. cit._) account leads me to suspect that some losses of poultry were charged to weasels when _Rattus_ was actually responsible.

Criddle and Criddle (1925:146), quote a neighbor in the vicinity of Treesbank, Manitoba, as recording that on October 29, 1917, "A weasel last night made its way into our fowl-house, the door being inadvertently left open. The weasel killed eleven fowl, some of which were dragged into the yard. All the largest fowls were selected, the pullets remaining untouched though they were in the majority. Next night the weasel dug a hole beneath the building and killed a hen and two cocks, returning for another during the day, making a total of fourteen in all." Criddle and Criddle (1925:146) remark that the weasel proved to be a large one, probably an old male. The same authors (_op. cit._:147) record that at their farm at Treesbank, Manitoba, on January 31, 1925, "A Long-tailed Weasel killed three hens last night, and rather severely bit a cock about the neck. This, or another weasel, had been around the farm-yard for sometime (The specimen was a large male). . . .

"In the fall of 1924, Mr. A. Cooper, a prominent poultryman of Treesbank, observed a large weasel carrying a freshly killed rat which it stored below ground and then returned towards the poultry-house, causing no little apprehension to the owner. Within a short time, however, the weasel reappeared with another rat which it hid as before. In this way several rodents were accounted for during the afternoon, and Mr. Cooper assures us that the weasel 'kept up the good work for same days'.

"Being a farmer of many years' standing, Mr. Cooper has naturally lost some poultry through the agency of weasels, but while he remarks that 'there are good as well as bad actors among weasels', he has the practical good sense to recognize the value of an efficient ratter even though it be a weasel.

"Our sister, Maida Criddle, writes under date of March 4, 1925:

"'There is another weasel (_longicauda_) in the fowl-house, a well-behaved one this time. It came and took a piece of meat out of my hand quite nicely, which it carried down a hole and then came and sniffed all over my mitt to see if there was any more. I thought it had been killed when I visited the farm buildings next day as there was a strong smell of musk on the cat and in the fowl house, but the weasel was there as cheeky as ever. It got hold of my skirt twice and tried to pull me down its hole. I think it wanted the cloth for a bed, as it was taking straw and other material down the burrow. The poultry were very frightened at first, but they are getting used to the weasel's presence now'."

In commenting on the economic role of the long-tailed weasel in Manitoba, Criddle and Criddle (1925:145) write as follows: "Supply and demand are prominent factors in governing our weasels' food habits. The two smaller species, as we have already pointed out are so dependent upon mice for a living that they increase or diminish with the fluctuation of these creatures. The Long-tailed Weasel, however, is not so easily checked by the temporary disappearance of any particular kind of game. If mice are scarce it devotes greater attention to gophers or bush rabbits and if these are not in sufficient numbers to satisfy its appetite, the animal raids a poultry house as a last resource. In nine years out of ten, this weasel will find sufficient food about the fields and woods, but on the tenth it may be obliged to temporarily turn to domestic animals. It is at such times that the weasel is seen and its deeds recorded. A thousand mice may have been killed in the meantime, but the destruction of half a dozen hens is alone used as evidence of the weasel's economic standing.

"In the last twenty years we have permitted weasels to frequent the farm buildings at will and the poultry house has been no exception. In that time rats and mice suffered severely from the weasels, while the total number of poultry taken were six. Many times that number, however, have been killed by rats.

"When we review our experiences of the past, we are astonished to find what few poultry have been killed by weasels. Our own losses in forty-two years have not exceeded fifteen birds and even these were usually eatable. There have been reports of losses from time to time from neighbors, but on looking into details we find that there are very few farmers who have experienced more than three separate occasions of weasel depredation and the total loss per farmer in the last thirty years does not, we are sure, exceed ten birds. This is surely a remarkably small payment to weasels in general for the great good done by them in killing rodents.

"We wish to point out, too, that only the exceptional weasel becomes a poultry killer. In most cases apparently it is a fully-grown male that does the killing. There are exceptions, of course, but when we see a large weasel actively engaged in rodent hunting within a few feet of a brood of newly hatched chickens and not even looking at them, we must at least pause to ask if this animal is the enemy that we were taught to believe it to be."

A suggestion that weasels sometimes obtain the prey killed by hawks is offered by Criddle and Criddle (1925:147) who write: "Hawks are not always the aggressors, as is shown by an incident reported by Mr. H. L. Seamans, of Lethbridge, Alberta. Mr. Seamans noted a large buzzard suddenly fly straight upwards from a fence post, and then alight upon another one some distance away. A little while afterward this bird once more arose in the same manner as before, and presently repeated the performance again. An investigation then followed and revealed that a Long-tailed Weasel was following the hawk from post to post.

"We should hardly expect a weasel to attempt to capture a bird of the above type. On the other hand, it is possible that these animals might be able to startle a hawk sufficiently to cause it to drop its prey, which would thus provide food for the weasel."

The following frequency index is compiled from the foregoing data on prey of _Mustela frenata_.

Moles (family _Talpidae_), 5
Shrews (family _Soricidae_), 26
Pigmy weasel (_Mustela rixosa_), 1
Ground squirrels (genus _Citellus_), 23
Chipmunks (genus _Tamias_), 38
Tree squirrel (possibly all _Tamiasciurus_), 8
Flying squirrel (genus _Glaucomys_), 1
Pocket gophers (family _Geomyidae_), 34
Mice (order _Rodentia_), 96
Harvest mice (genus _Reithrodontomys_), 36
Grasshopper mouse (genus _Onychomys_), 1
Deer mice (genus _Peromyscus_), 235
Cotton rat (genus _Sigmodon_), 2
Wood rats (genus _Neotoma_), 14
Meadow mice (genus _Microtus_), 248
Muskrat (genus _Ondatra_), 1
Old World rats (genus _Rattus_), 19
House mouse (genus _Mus_), 1
Jumping mouse (genus _Zapus_), 5
Varying hare (_Lepus americanus_), 5
Rabbits (genus _Sylvilagus_), 48
small birds, 32
chickens, 17
lizard, 1
snakes, 4
insects, 3

More significant than the above compilation, of course, are the results of careful studies of the food of the long-tailed weasel in restricted areas. Examples of such studies are those of Polderboer, Kuhn and Hendrickson (1941) and Hamilton (1933:333).

According to Hamilton's (1933:332) observations on captive weasels, "There seems to be little relative difference in the amount they eat, regardless of their activities.

"In general, more food is taken in summer than in winter. Usually about a third their weight every 24 hours is eaten, but a growing young weasel will consume much more. A young male _noveboracensis_, weighing 145 grams, consumed an entire chipmunk, fur and bones, weighing 85 grams, in 24 hours. A day later it ate all of a partly grown rat, 105 grams, in the same length of time."

Moore (1945:253) records that a captive male that he obtained at Gainesville, Florida, consumed, on the average, between 63 and 70 grams of flesh and blood per day. The weasel itself weighed approximately 320 grams.

Sanderson (1949:413), concerning seven young weasels from Manitoba, that he raised in captivity, writes: "From the fifth to the seventh week of age, they consumed approximately 22 per cent of their body weight per day; from the eighth to the tenth week (just before reaching mature size) they consumed approximately 24 per cent; but after reaching maturity they consumed only 18 per cent. When given all the food they would take in one day, they ate as much as 40 per cent of their body weight."