Shrew diet is very much dependent upon supply. The shrew has a very large pallet of foods they will eat including insects, small mammals and plant material. They are well known for their voracious eating habits which often lead the animal to eat nearly three (3) times their weight each day! With that kind of appetite it is not difficult to see how a large population of shrews could cause problems for the backyard gardener.
While the shrew diet consists of most anything edible out of doors, they do favor insects over anything else. Some of their top picks are beetles, crickets and grasshoppers. They will also eat smaller insects including centipedes and millipedes and smaller wasps. Butterfly and moth larvae are considered tasty little morsels, as are the more meaty snails, slugs and worms. Not all species of shrew eat plant materials but those who do, including the Northern Short-tailed Shrews, partake in berries, seeds, nuts and roots. Small mammals, amphibians and birds are also taken including those larger than the shrew itself! This can be snakes, frogs, salamanders, mice, and even other shrews!
Shrew Diet-Physical Attributes
You may be asking yourself how such a small animal can eat animals larger than itself. In the case of the Short-tailed Shrews this accomplished through the use of poison. These shrews produce a toxin in their teeth that render their prey helpless once bitten!
Most other shrews use echolocation to find their next meal. They will search though ground litter and dig burrows by emitting a high pitched call that bounces back to them when it hits an object. Scientists believe that this is how the shrew detects insects underground.
The shrew diet is urged on by a super fast metabolism. It has been determined that the shrew’s heart beats nearly 700 times per minute (on average) and could only survive a few hours without food. Additionally, because the shrew does not hibernate the process of eating generates much needed heat during the winter which may help the animal survive the coldest days of the year. To keep going they will store food for the wintertime when food availability is limited.
Shrew Diet-Benefits and Detriments to Humans and the Ecosystem
The shrew diet can have great benefits to humans in that they eat a huge number of insects that some may consider pests to garden plants and even larger agricultural plots.
Unfortunately, they have been known to attack birds and even chipmunks at backyard feeders which can be quite upsetting. That voracious appetite may lead them into your food stores as well which can cause contamination of the pride of your harvest!
Stored foods, song birds and your fall harvest are some of the detriments to humans and the ecosystem from the shrew diet.