100 Order CARNIVORA 



auditory bullae are inflated and long anteroposteriorly. The 

 over-all length of the skull in the male is 43-50 mm. (about 

 \J4 inches) ; in the female, 30-42 mm. (about ll/ inches). 

 Dental formula: I 3/3, C 1/1, Pm 3/3, M 1/2. 



Life History. — The long-tailed weasel occurs over much of 

 Illinois in brushland, along shrubby fencerows, in haystacks, 

 in brush piles, and sometimes under farm buildings. It preys 

 principally on rodents and is most apt to be found where small 

 mammals are abundant. In Illinois, as in other states, it feeds 

 heavily upon voles, white-footed mice, ground squirrels, rabbits, 

 rats, birds, insects, and, in fact, upon almost any animal it can 

 overpower. 



A hungry long-tailed weasel, once on the trail of a rabbit, 

 is an intent, relentless pursuer. A healthy rabbit, however, will 

 give the weasel a good run and may cleverly confuse its own 

 trail by hopping back and forth over a small area. Again, the 

 rabbit may freeze motionless and be nearly lost to sight in a 

 tangle of brush so that the weasel may pass it by momentarily. 

 The rabbit may make a confusing maze of tracks before dashing 

 off, and the shorter-legged weasel must hustle to keep up with its 

 prey. But once the gap is sufficiently narrowed between predator 

 and prey, the weasel makes a quick dash and bites the rabbit at 

 the base of the skull. Over and over the two may tumble, the 

 weasel holding on tenaciously until the rabbit ceases to struggle. 



The long-tailed weasel usually makes its home in the burrow 

 of a ground squirrel or larger mammal, after slightly remodel- 

 ing the entrance and nest. A few droppings near the entrance 

 and bluebottle flies humming about announce that the burrow is 

 no longer occupied by a seed- or herb-eater but by a carnivore 

 that has a store of meat inside. Dry grass, leaves, and mouse 

 fur are common nesting materials of this weasel. 



An adult female gives birth annually to a single litter of 

 young, usually four or five in number, in the spring. Throughout 

 the first month the young remain in the den, and food is brought 

 to them. Soon they are providing their own food. When 3 to 4 

 months old they are nearly full grown. An adult weasel can 

 consume each day an amount of flesh equivalent to about a 

 third of its weight. 



Signs. — Tracks of the long-tailed weasel, like those of the 

 mink and the least weasel, are seen usually in the bounding 

 pattern, the long prints of the hind feet leading and the short 



