Speaking of nature: a little surprise: the short-tailed shrew

As the month of September came to an end, my efforts to collect as many bird sightings as possible paid off. Somehow, despite the fact that school had started again and my time was limited to weekends, I managed to set a new record for the number of species observed. The previous record, set in 2021, was 50 species. At the time of writing this particular column, I had recorded 52 species and it all came down to the time I spent in my thinking chair.

This may shed some light on the qualities of birds that make them so interesting to watch. In all that time, while compiling a list of 52 species of birds, I only managed to see 6 species of mammals. Twice I saw a cottontail, three times I saw a red squirrel, twice I saw a gray squirrel, and once I saw a prairie vole. Then there was one day that I observed a chipmunk in the seeds. These 5 mammal species are species one would normally expect to see in a place where short grass and canary grass are available, so there was nothing particularly surprising on this list.

But where were the deer? Why have I never seen a fox, coyote, raccoon, opossum, skunk, bobcat, or weasel of any kind? The simple answer is: I don’t know. Perhaps my presence, though calm, is bold enough to warn these species. Or, more likely, these species are much lower in number and have no particular reason to walk the trails too often. Maybe if you put a motion-sensitive camera on the thinking chair you’d see all kinds of mammals at different times of the day. Who knows?

But there was a sixth species of mammal that made a surprise visit twice in the past month. In the same patch of short grass where I place seeds for song sparrows and where I had previously seen voles, another species of mammal showed interest in the food I had placed there. It was a short-tailed shrew (Blarinabrevicauda) and its behavior pointed to the incredible value of birdseed as a food source.

The short-tailed shrew is an animal that falls into a category called “insectivores.” About the same size as a mouse or vole, the short-tailed shrew has a very different body type. Instead of being plump, the shrew is slimmer and more slender. Covered in short gray hair that reminds me of velvet, the shrew also has very small ears and extremely small eyes that could be on the verge of becoming vestigial.

The reason for all of these physical characteristics becomes obvious when you consider the shrew’s diet and its method of hunting for food. Largely carnivorous, the short-tailed shrew has an extremely high metabolism that requires it to eat up to three times its own body weight every day.

Shrews are voracious predators and this particular species likes to spend most of its time underground, where it can find worms, insects and other small animals to feed on. To help it dispatch its prey, the shrew has poisonous saliva. In essence, the shrew is the mammalian equivalent of a rattlesnake, and its bite contains enough toxin to paralyze an animal slightly larger than itself. Therefore, mice, voles, and even other shrews should beware if a hungry shrew is on the prowl.

But despite the fact that the shrew is a carnivore, and despite the fact that all of its teeth are adapted to killing and consuming animal prey, it seems that such a high rate of metabolism will force the shrew to eat anything else it eats. it could be. edible and available. This means that edible mushrooms will be consumed and, luckily, the birdseed will also be devoured. I can’t imagine that there is much difference between a small beetle and a sunflower seed. They both have hard shells and something delicious hidden inside.

Then, as I watched the birds come and go, I noticed another little visitor darting in and out of the tall grass to steal seeds and eat them in the more private gloom of the undergrowth. A shrew is a small, vulnerable species that faces heavy predation from owls and a wide variety of mammalian predators, but the need for food is so great that a shrew simply cannot pass up an opportunity when it finds something so nutritious out there. pulled. All I had to do was point my camera and take what seemed like a hundred photos until I finally got a photo that showed some detail. If you ignore the fact that I was sitting in a wet plastic chair early on a Sunday morning when the temperature was only 42 degrees, then it was a doddle.

Bill Danielson has been a professional writer and nature photographer for 25 years. He has worked for the National Park Service, US Forest Service, Nature Conservancy, and Massachusetts State Parks and currently teaches high school biology and physics. To learn more, visit his website at www.peakingofnature.com, or head over to Speaking of Nature on Facebook.