MAMMALS. 87 



tive fur puts a high value on their skins. Their destruction of fish 

 is apparently not serious, although they feed quite extensively upon 

 minnows and small fish, which they catch alive, but it is probable that 

 the larger fish caught are the sick or injured individuals. 



Arizona "Weasel: Mustela arizonensis (Mearns). — These are me- 

 dium sized weasels with buffy brown backs and white lowerparts in 

 summer, but in winter pure white, except the tip of the tail, which 

 is at all seasons black. They are probably the commonest weasel 

 throughout tiie park and may be found at all altitudes and in all 

 kinds of country from the deep woods to the open meadows and bare 

 slopes above timberline. In June, 1895, I caught one on a log over 

 a creek at St. Mary Lake. They are great hunters and wanderers 

 iiud seem to be incessantly chasing over logs and under brush, 

 through rock piles, and from burrow to burrow and nest to nest of 

 the small game which they pursue. Apparently they have no choice 

 of day or night for hunting, but simply hunt until their appetites 

 are satisfied and then keep on hunting for the pleasure of killing, 

 (xround squirrels, chipmunks, mice, and all small rodents are at once 

 thrown into a panic when a weasel appears on the slope, and with 

 loud calls warn each other as far as possible in advance of a danger- 

 ous enemy. Even the pocket go]:)her in his tunnels underground is 

 not safe if an open door can be found or an entrance forced into his 

 galleries. He is relentlessly followed up and ciuickly dispatched and 

 devoured and often his burrow is used as a temporary residence while 

 the other rodents in the vicinity are being killed and eaten, or killed 

 and left uneaten. Any thing of the weasel's own size or even con- 

 siderably larger is fair game, but I have never known of this species 

 killing the snowshoe rabbit. The conies are greatly excited by the 

 appearance of a weasel, and many of the colonies that seem to have 

 disappeared were probably exterminated by weasels, which readily 

 follow their runways under the rocks and give them no chance 

 of escape. In winter their tracks are seen in long zigzag lines over 

 the snow, or they disappear at a round burrow which has been forced 

 down through the snow to the surface of the ground, where mice and 

 squirrels and pocket gophers have their runways and can be fol- 

 lowed up and caught. The pure white winter coats, however, have 

 a market value, and great numbers of weasels are caught in the lines 

 of traps set for minks and martens and more valuable game. While 

 not sufficiently large and long furred to be as valuable as the Old 

 "World ermine, their pure white skins are extensively used for furs. 



LoxG-TAiLED "Weasel : Mustela longicauda longicauda Bonaparte. — 

 These large, long-tailed, yellow-bellied weasels also are buffy brown 

 in summer and pure white in winter, except for a usual suli)hur- 

 colorecl stain over the belly and the long black tip of the tail. 



