Now that the camera is back on the ground, I’m getting mostly chipmunk photos, which is unsurprising given that it’s on a seed pile behind a hedge in Madison, WI. I’m trying to figure out how to get the most useful info from the photos I have. Not that identification is much a challenge with this species, but I got some nice “documentation shots” of field marks. As mentioned, they’re “brightly-colored” as mammals go, with distinct patterning on the fur. Part of the pattern is the 5 dark lines that run dorsally along the animal, with the mid-line being the longest. The paired dark lines on either side of the chipmunk outline a white stripe. I think this is easiest to see in photos where the chipmunk is sitting facing directly away from us.
The facial pattern of chipmunks is distinctive with alternating light and dark lines. Also, look at those big eyes! It’s hard not to think of these little guys as cute. I’ve counted 3 chipmunks at once under the feeder, so unsure if there are more than that in the yard. They also seem to have different coloration, but I don’t know much about identifying and differentiating individuals reliably. One of them has a lot of furry white behind the ears, and another is really richly colored. I was surprised to find that they have an average lifespan of less than a year (but can be up to 5)! Maybe these chipmunks are young from last year. I captured this photo (below) of the rusty sides that line the white belly, showing a touch of how colorful this small mammal can be.
And of course, what do most people think of when they think of chipmunks? At the seed pile, I see and get plenty of pictures of filled cheek pouches! This photo is dark, but notice the 4 toes on the front paws. This was when the seed pile was full of cracked corn, though chipmunks aren’t picky. They’ve come to every seed blend I have put out (mostly Havegard and black oil sunflower).
I think I’m capturing molting of an eastern chipmunk in some of these photos: in late spring, male chipmunks molt into their summer coat. Apparently, the molt sequence is the same as that of red squirrel, so I tracked down the old paper describing red squirrel molt to compare notes with the chipmunk photos (Yerger 1955).
“The first changes occur either around the nose and under the chin, or on the front feet; or the molt may begin at these two places at about the same time.” – Bernard Nelson, Spring Molt of the Northern Red Squirrel in Minnesota
“The molt begins later on the hind feet, but usually before much change has occurred on the back. On the front feet the molt commonly proceeds faster on the inner side of the feet, many specimens showing the ochraceous summer coat to the heel on the inside while on the outside of the feet the winter coat persists almost to the end of the toes. A similar unevenness in the appearance of the summer coat is seen on the hind feet, but either side of the foot may change color first. In the early stages, the molt frequently begins on a single row of phalanges of the hind foot first, usually the second row from the claws, while the distal row remains unchanged.” – B. Nelson (1945)
As you can imagine, it’s tough to get photos of the hind feet, but I’ll keep looking!
“The sides of the head ordinarily assume the summer pelage before the top of the head. The molt is also complete along the flanks and on the underparts before the back has changed pelage completely. The molt on the back is often ragged and irregular, with the rump retaining the winter coat the longest.” – Bernard Nelson (1945)
Nelson, B. 1945. The Spring Molt of the Northern Red Squirrel in Minnesota.
Yerger, R. 1955. Life History Notes on the Eastern Chipmunk, Tamias striatus lysteri (Richardson), in Central New York.
As I’ve mentioned in prior posts, my Audubon Wingscapes feeder cam doesn’t really focus closely. It claims the range is 18-23″, but to get a crisp photo, you really need to be at the far edge of that range. Alas, the mounting arm I bought specifically for this camera is pretty short. I decided to mount my feeder so that it wouldn’t blow in the wind so much, and as a result, the camera arm was too short to allow the camera to focus. The distance from the camera to the side of the hopper was only 17″! I finagled it a little to try to get it farther away, but composition suffered. As “diagonally” as I could angle the camera from the point I wanted to focus on, I still couldn’t get it quite right. So, I forewent my hard work of setting all this up and went back to my original scheme: on the ground.
Nothing amazing so far, but much nicer pics already! Even in decent light, it seems to be capturing closer photos, too. Bonus: it’s closer to the router so the auto upload seems to be working. Unfortunately, the online upload doesn’t work anymore, so I have to have my laptop on to get the photos. Yet, it’s better than manually taking out the SD card!
Now, a little about the eastern chipmunk that already seems to love this new setup: it’s widely known that they store seed in their buccal pouches, as pictured. I have black oil sunflower seed scattered on the ground, and this guy will take as much as he can fit in his cheeks! He has so far been the most frequent visitor to the seed pile, and I’d be surprised if that didn’t continue so long as he lives around the house. The chipmunk tail is described as “moderately furred” and somewhat flattened. What surprised me, though, was the rusty color under the tail I captured in this photo.
It appears to be predator defense, as they flick the tail upward when they run. After searching, I discovered that they do this to increase the chances that an attacking predator would bite the tail instead of the body, to minimize damage. Maybe the brighter color under the tail aids in the distraction! Also, I’m pretty sure it’s a male…
Apparently the darker the fur on the scrotal sac, the more mature the chipmunk!