The long-tailed weasel (Mustela frenata) is a small, savage carnivore that readily preys on larger animals, which it kills by biting with ruthless speed at the base of the skull. This weasel lives and hunts where there is dense cover and an abundance of small rodents. Hunting diurnally, its diet consists mainly of mice, rats, ground squirrels, birds and rabbits. The weasel will also take domestic chickens or other fowl. They have also been reported to kill and cannibalize other weasels.
The summer coat of the long-tailed weasel is reddish-brown with cream underparts. The slender tail is tipped with black. In cold climates the winter pelage is white except for the tip of the tail which remains black.
I find it interesting that the gestation period of the long-tailed weasel is about 279 days, in the nine month range. Long-tailed weasels mate in July or August with the litters arriving the following spring. The blastocysts (very young embryos) float around in the uterus and do not attach to the uterus wall and begin to develop until about four weeks before parturition.
Recently Leonard and I discovered a dead long-tailed weasel in the Ash Creek Wildlife Area. This weasel likely was in the midst of its spring moult because the white winter coat was loose and the tail was already turning brownish. There was a wound on the back of the neck and scratches on the face. The blood was still red and not coagulated and the weasel’s body was limp, leading us to believe it had not been dead long. It was a good opportunity to study this elusive creature.
What happened to this weasel is confounding. A raptor or coyote would have taken the light corpse with it if disturbed. (We did not see, nor was there a sign of any such predator.) What else could have killed the weasel? We speculate that perhaps another weasel was the culprit. Any other theories would be appreciated. After extensively photographing and examining the weasel and its injuries we left it for the scavengers.
The picture of the long-tailed weasel in its summer coat was taken at a different location in the wildlife area (Modoc County CA) late last spring.