Oct 12, 2017

Chipmunks are a common sight here in the Northwoods, but how much do we know about them, or pay attention to them? In this episode of wildlife matters, the Masked Biologist takes you on a voyage of chipmunk discovery.

I recall walking through a parking on one occasion when an unusual sight caught my eye – a chipmunk was sitting on the pavement, contentedly eating a small bird. There wasn’t much left by the time I discovered the scene, so I don’t know if the chipmunk found the bird dead, or if it captured and killed it. I suspect it found the bird injured and killed it; I have never seen a chipmunk eat dead animals. I have seen chipmunks eat live animals though. Once I was driving through the woods and I saw a frog hopping out on the gravel road in front of me. A chipmunk was behind it, in full pursuit. It was a horrific struggle, like watching a really tiny cheetah taking down an itty bitty green gazelle. Once the frog was done in, I rolled forward and the chipmunk ran off, dragging its prize into the underbrush. Since that time, I have researched, and learned, a lot about this interesting creatures.

You may be surprised to learn that there are four different species of chipmunks that occupy all or parts of Wisconsin. The Ohio chipmunk is found in far southern Wisconsin, and the peninsula chipmunk is found on the Door County peninsula (naturally). Here in the northern half of Wisconsin, we have two species of chipmunk, the gray (or eastern) chipmunk and the least (northern) chipmunk.

There are many different common names given to these creatures. Being a biologist, we typically use the Latin names to discern between two similar animals, so I might call the eastern Tamias and the least Eutamias. As I was researching these animals in my reference materials, I found that the Ojibwa have names for both distinct species; the eastern is gwen-geesh, and the least is ah-kwin-quis. Since this is a spoken medium, and I don’t speak fluent Ojibwa, I won’t embarrass myself by trying to pronounce them. So, for ease of understanding, I will use eastern to refer to the gray chipmunk and northern to refer to the least chipmunk.

Eastern is 9.5-11 inches from nose to tail tip, larger than northern by a fair margin. Northern is between 7.5 and 8.5 inches long, including the tail. Eastern tends to live in more deciduous environments, meaning trees that shed their leaves in fall. Northern prefers more coniferous areas, or areas with a lot of trees that produce cones. Early in the last century, northern was probably far more common in northern Wisconsin. Eastern moved in, though, and there were naturalists that predicted that eastern would completely displace northern in the north. However, the species live together in the same habitat quite harmoniously, and both seem to be doing well. Both species are typically ground dwellers, but can climb and swim well. Eastern is a bit less agile and playful than northern, and probably not as quick. Northern can run up to 15 miles per hour. Both are similarly colored and striped, but northern has stripes that go all the way to the base of the tail; the stripes on eastern end before the tail base.

Chipmunks might live 3-4 years, re-using the same burrow complex throughout its life. Chipmunks haul dry goods like nuts and seeds into the winter burrow using the pouches inside its cheeks, There they will consume them from mid-November until they emerge sometime in April. Love them or hate them, Eastern and northern are fascinating animals. See if you can tell them apart next time you see one.

Striving to make new things familiar and familiar things new, this is the Masked Biologist coming to you from the heart of Wisconsin’s great Northwoods.