Thought I would share what I know about mustelid killing behaviors, having
watched more than a thousand "kills" by various mustelids.
 
Mustelids are a wildly diverse group, which means they have a number of
prey-killing strategies, so I will limit the comments to those of the
subgenus Vison, which includes mink, weasels, polecats, and domesticated
ferrets, (but much of what I will write about can be applied to martens,
fishers, sables, etc.) Hunting behaviors in this group are remarkably
similar, so what is generally said of stoats can be applied to polecats, and
that of polecats to ferrets, etc.  They are all small predators that eat a
varity of creatures, ranging from insects to fish and from amphiphians and
birds to small mammals.
 
Because of their small size, they are in constant danger of the prey turning
and hurting them.  With rabbits and rats, this is especially dangerous, and
there are many reports of both rats and rabbits seriously injuring and even
killing stoats, polecats, and ferrets.  As a result, they have developed a
wide range of hunting strategies to minimize the risk, so a particular
hunting method is correlated to prey size and species.  However, there are
some generalizations that hold true.
 
The most common method of killing (by far) is by crushing the base of the
skull using a forceful bite.  (Because of the biomechanical construction of
the mustelid jaw, their bite is particularly forceful.  One biomechcanical
author wrote that he thought that pound-per-pound, the mustelids had the
strongest bite in the class mammalia.  While I have never been biten by a
hyaena, which can crush elephant bones in their jaws, I have been bit by a
number of mustelids--like mink--and can vouch for the nastiness of the
experience.  I would hate to think what they could do if they were the size
of large dogs.) The second most common method is by crushing the first or
second cervical vertebra in the neck which attach to the base of the skull.
Both methods either crush the cerebellum and/or pons, destroy the spinal
cord, or disrupt the flow of blood to the brain--making death instantaneous.
This is very important for such a small predator so they not only conserve
energy making the kill, but also vastly reduce the chance of being injured
themselves.
 
For animals smaller than themselves, usually the mustelid does a "spring and
bite" or the much-discussed "torpedo run." The rush in and bite method is
very effective for voles and mice, which the pounce and bite seems to work
better for insects and amphibians which aren't much of a danger.  For more
dangerous animals about their size or larger (like rats and rabbits), a
different set of tactics is employed.  Normally, the mustelid will attack
the nose and face of the prey animal, biting until the prey is weakened from
lack of blood, goes into shock, is blinded, or is otherwise unable to defend
itself.  Once this takes place, the bite to the back of the head is
employed, and the animal is quickly dispatched.
 
Often during these dangerous encounters, the mustelid will bite and roll, or
bite and shake the prey.  The roll method, especially with a facial bite, is
very distructive, and quickly renders the prey unable to defend itself.  The
shake appears to increase the injury caused by the bite, crushing bone,
severing tissue, and increases bleeding.  While these techniques have been
reported being used on prey smaller than themselves, it is usually reserved
for the larger prey, and seems designed to increase the success of the hunt
while decreasing the chance of injury.
 
The two most commonly consumed portions of the mammalian prey includes the
brains and the hindquarters, while in birds it is the brains and breasts,
but these represent disturbed kills.  Usually the mustelid will carry the
prey to the "hidey hole" for later consumption, and little is left uneaten.
If surplus animals are available, the mustelid will kill as many as
possible, and store the uneaten prey in safe locations, but this is
relatively rare in the wild--most commonly seen in situations where the
mustelid takes advantage of human caging practices (henhouses, duck ponds,
etc).  These behaviors are designed to maximize nutrition; one never knows
when a larger predator will steal your food or try to make you lunch only to
eat yours after you make an escape.
 
As can be easily seen, the behaviors as described are mirrored in the
ferret's play, sex and dominance behaviors.  Stashing toys, neck bites and
rolls, torpedo runs, and reaction to high pitched sounds all betray a
predatory origin for a domestic pet whose kin are among the oldest and most
successful mammalian predators that ever lived.  What you are seeing is
unhoned instinctual responses, and alone will not necessarily insure
survival in the wild.  Mustelids must be taught how to hunt and what to eat,
and so have a long period of learning at their mother's side, up to 1/4th or
more of their total lifespan, compared to 1/8th to 1/10th (or less) for dogs
and cats.
 
I once had a professor that said cats were never domesticated, they just
pretended to be for the free chow.  Dogs were just too dumb to know the
difference.  What has this to do with the prior discussion?  Nothing...I
just wanted something witty to end on after such a gruesome discussion.
 
Bob and Mo'13
 
"If it moves, bite it, if it runs, jump on it, if it squeaks, hide it,
and if it does nothing, then for heaven's sake poop on it."
[Posted in FML issue 1553]