Short-tailed Shrew

by Carl Strang

A few days ago I saw my first two short-tailed shrews at Mayslake Forest Preserve. Both were dead.

short-tailed shrew b

This one was in the middle of the trail. The other was in a mowed area, a few feet out from the edge of a prairie. These almost certainly were killed by coyotes. They appear to have been left as calling cards in the same way that coyotes deliberately place their scats in the centers of trails. Other coyotes coming along are sure to find them and know the area already is claimed.

I knew that short-tailed shrews were on the preserve, compliments of a great horned owl.

Owl pellet 1b

These skulls all were in a single owl pellet deposited in the center of the preserve last winter. The upper left one belonged to a short-tailed shrew. So, why would the owl eat these shrews, while the coyote leaves them after killing them? After all, if the coyote wants to use a small mammal as a marker, there are many more voles and white-footed mice, so we might expect the coyote to use them as markers, too.

Here I have no inquiry I can do myself. I must rely on what others have found. It turns out that short-tailed shrews are toxic. They have salivary poisons that help them subdue the voles that often are their prey, but some poisons are found all over their bodies. Owls, with their relatively poor taste and smell, gulp down any they kill (great horned owls also eat skunks, by the way). Coyotes are less inclined to do so. They pounce and kill a small mammal moving through the tall grass, then find it’s a shrew. Being resourceful while not wanting to eat something so vile tasting, they use it as a marker. At least, that is what I think is happening here. Another possibility is that the coyote deliberately kills the shrew with the intention of using it for communicating with other coyotes, incidentally taking out a competing predator.

%d bloggers like this: