SMALLER MAMMALS OF NORTH AMERICA 



469 



THE BLACK-FOOTED FERRET 



(Mustela nigripes and its relatives) 



{For illustration, see page 449) 



Of all the varied forms of mammalian life 

 in America, the black-footed ferret has always 

 impressed me as one of the strangest and most 

 like a stranded exotic. It is about the size of 

 a mink, but, as the illustration shows, is entirely 

 different in appearance and has the general 

 form of a giant weasel. It has no close rela- 

 tive in America, but bears an extraordinarily 

 close resemblance in size, form, and color to 

 the Siberian ferret {Mustela eversmanni) . 



The black-footed ferret occurs only in the 

 interior of the United States, closely restricted 

 to the area inhabited by prairie-dogs, from the 

 Rocky Mountains eastward and from Montana 

 and the Dakotas to western Texas. It is 

 known also west of the mountains in Colorado. 

 Like others of the weasel tribe, it must have 

 a wandering disposition, since one was captured 

 at 9,800 feet altitude, and another was found 

 drowned at 10,250 feet in Lake Moraine, Colo- 

 rado. 



These ferrets exist as parasites in the prairie- 

 dog colonies, making their homes in deserted 

 burrows and feeding on the hapless colonists. 

 In Kansas their presence in certain localities 

 appears to have been effective in exterminating 

 prairie-dogs, and similar activities may account 

 for the deserted "dog towns" which are not 

 infrequently observed on the plains with no ap- 

 parent reason for the absence of the habitants. 



They do not appear to be numerous in any 

 part of their range and little is known con- 

 cerning their habits. Now and then they are 

 seen moving about prairie-dog "towns," passing 

 in and out of the burrows at all hours of the 

 day, but it is probable that they are mainly 

 nocturnal. This probability is strengthened by 

 the extreme restlessness shown at night by cap- 

 tive animals. With the occupation of the coun- 

 try and the inevitable extinction of the prairie- 

 dog over nearly or quite all of its range, the 

 black-footed ferret is practically certain to dis- 

 appear with its host species. 



It has the same bold, inquisitive character 

 shown by the weasel, and when its interest is 

 excited will stand up on its hind legs and 

 stretch its long neck to one side and another 

 in an effort to satisfy its curiosity. When 

 surprised in a "dog town" it commonly retreats 

 to a burrow, but promptly turns and raises its 

 head high out of the hole to observe the visitor. 

 As a result ferrets are readily killed by hunters. 

 When one is captured it will at first hiss and 

 spit like a cat and fight viciously, but is not 

 difficult to tame. 



Although mainly dependent upon prairie-dogs 

 for food, there is little doubt that ferrets, after 

 the manner of their kind, also kill rabbits and 

 other rodents in addition to taking whatever 

 birds and birds' eggs may be secured. In one 

 instance a black-footed ferret lived for several 

 days under a wooden sidewalk in the border 

 town of Hays, Kansas, where it killed the rats 

 harboring there. 



THE LARGE WEASELS, OR STOATS 

 (Mustela arcticus and its relatives) 



(For illustration, see page 452) 



The weasel family includes not only the true 

 weasels, but numerous other carnivores, as the 

 sable or marten, mink, ferret, skunk, and land 

 and sea otters, all of which rank among our 

 highly valued fur-bearers. The large weasel 

 may be distinguished from others of its family 

 by the small size and the snakelike propor- 

 tions of^ the flattened and pointed head, com- 

 bined with a long, extremely slender neck and 

 body and a comparatively long tail. The best 

 known of these animals are the stoat of the 

 northern parts of the Old World (Mustela 

 erminea) and its close relative in northern 

 North America (Mustela arcticus), the winter 

 skins of which furnish the famed ermine, once 

 sacred to the trappings of royalty. 



The northern weasels are strongly marked by 

 their habit of changing their brown coat to 

 one of snowy white at the beginning of winter. 

 To the south the change becomes less com- 

 plete as the winter snows decrease, and south 

 of the limit of snow the brown coat is retained 

 throughout the year. The time of change de- 

 pends on the coming of the snow and varies 

 with the year, and the time of resumption of 

 the brown coat in spring depends in the same 

 way on the season. The white winter coat of 

 the larger and medium-sized species is accom- 

 panied by a strongly contrasting jet black tip 

 to the tail. 



Weasels are circumpolar in distribution and 

 occupy nearly all parts of Europe, Asia, and 

 North and South America, the greatest number 

 and variety of species occurring in North 

 America. Surprisingly enough, the largest of 

 these eminently northern animals is found in 

 the forests of the American tropics. The Arctic 

 weasel ranges to the northernmost polar lands 

 of North America, where its presence has been 

 recorded many times by ice-bound explorers. 

 Other species are more or less generally dis- 

 tributed over the remainder of the continent. 

 In Mexico I have found them from sea level 

 to above timberline, at more that 13.000 feet 

 altitude on the high volcanoes. 



The strong personality of the weasels as a 

 group is based mainly on their extraordinary 

 celerity of movement, their courage, and their 

 insatiable desire to kill. They are not satis- 

 fied with supplying the call for food, but when- 

 ever opportunity arises kill from sheer lust of 

 slaughter. 



Their slender forms enable them to follow 

 their prey to the remotest depths of their re- 

 treats, and that all rodents have an abiding- 

 horror of them is shown by the effect of a 

 weasel's appearance. Rabbits, although many 

 times their size, become easy victims, and in 

 one instance when a large rat, which had 

 fought its human captor viciously, was put in 

 a cage with a weasel, it at once lost all its 

 courage and permitted itself to be killed with- 

 out an effort at defense. 



Weasels are wonderfully endowed for their 



