Tracking Challenge 2: Squirreling Around

​Author: Teri Lysak, Tracking Leader with the Wolverine Tracking Project

TRACKING CHALLENGE 2:
Squirreling Around!
Send us your photos of squirrel tracks and sign!
Winners will be chosen for:
- the clearest squirrel tracks,
-the most unusual squirrel tracks, and
- the most unusual sign!
Challenge Ends: March 15
Send photos to: wildlifesurveys@cascadiawild.org
Or, tag us on social media! #CaWTracks
Send us all your tracking questions and stories, too!

A Douglas squirrel says hello to one of our Wolverine Tracking Project wildlife cameras on Mt. Hood.

Did you all get to enjoy the snow we received over Valentine's Day Weekend? I have never seen so much snow in Portland before! The snow was deeper than the tops of my boots as I walked along the sidewalk, and more was still coming down. There weren’t many tracks to be seen, apparently not many animals were venturing out in those conditions. The only tracks I saw were people and dogs - and one squirrel!

Squirrels are a great place to begin if you want to study the ecology of your backyard. Although they are very common, studying squirrels can take you on some quite unexpected journeys.  

​There are four species of tree squirrels in our area: fox squirrels and eastern gray squirrels, both of which are non-native and found all over the city; Douglas squirrels, which are associated with conifers; and western gray squirrels, which were historically associated with oak savannas but have now become very rare.

A Douglas squirrel captured by one of our wildlife cameras on Mt. Hood.

A western gray squirrel captured by one of our wildlife cameras on Mt. Hood

I see squirrels fairly regularly. Seeing them is fun, but to really learn about them, I look for their tracks and sign. To a tracker, the word “sign” refers to anything other than tracks that shows you that an animal was there. Sign can include food scraps, beds, digs, scat, and so on. Tracks and sign can really teach you a lot about an animal and their ecosystem!

Squirrel Sign

One of the more obvious types of sign that tree squirrels make, obvious in winter at least, is nests.

​Squirrels build round balls of leaves to live in, thicker ones for winter, smaller ones for summer. What do nests tell you about squirrels? That they need to stay warm!

Not all animals have this problem. Deer, in contrast, have fur that is spectacularly well insulated and are able to bed down right in the open, even during the coldest of winter; sometimes, snow won’t even melt off their backs. Squirrels, on the other hand, have really short fur and not a lot of body fat. Just like us, they need to build a home where they can sleep and stay warm.

A squirrel nest made of leaves in the upper branches of a tree.

​Another sign I see a lot is this:

A small pile, or midden, of conifer cone bracts left behind by a squirrel feeding on the cone's seeds.

One of squirrel’s main foods is conifer cones, in this case a Douglas fir cone. In order to get to the seeds inside, the squirrels have to first chew off the bracts, the flat pieces you see scattered about.

A midden pile left by a squirrel eating in the nearby tree. Photo: Kimber Nelson.

Often, piles of this feeding debris accumulate in one spot, as seen in the picture to the left (or above if you're on a mobile).

Curiously placed! Obviously, this squirrel was not eating the cones wherever they landed. It was carrying them to a very particular spot, over and over again, to eat.

To understand this, let’s think about ourselves again, and our eating behaviors. Where do we eat? In general, given a choice, we eat near where the food is prepared and where we feel safe. Squirrels and other animals are the same way, and for squirrels, this often means they eat up in a tree, where they are safe from most predators. The cone debris then falls to the ground and collects in a pile beneath where they were sitting.

On the topic of squirrels and cones, I heard a funny story from fellow Tracking Leader Graham Hulbert about when he was doing trail maintenance on the Mt Hood National Forest. I quote:  “I wandered into the woods a little ways but was almost ambushed by a 4-pound cone falling from the top of a grand fir. I thought it was fluke that it fell down until, upon inspection, I saw teeth marks in the green branch attached to the cone - it had been chewed through! Luckily, I had my hard hat, so I put it on – and right in time - another cone came crashing down, followed by the barks of a disgruntled Douglas squirrel at the top of the tree, yelling at me as if they could only assume I was trying to pilfer their delicious treats!” 

A Douglas squirrel, likely en route to forage, captured by one of our wildlife cameras on Mt. Hood.

This story tells us another important fact about squirrels – they actively gather and store cones. Again, they are like us. Plant food doesn’t grow during the winter, so in order to survive, both of us harvest and store food in the fall. This is a good alternative to hibernating!

​Some cone debris piles I’ve seen can get very large, like this one below:

Squirrel tunnels where cones are cached, built in a midden made out of the refuse of past-eaten cones. Photo: Kimber Nelson.

In the picture above, the mound at the base of the tree is a huge accumulation of cone remains! There are several tunnels in the middle of it, where the squirrel has repeatedly gone in to get a cone and come out to eat. In this case the squirrel's safety zone isn’t a tree, but an underground tunnel. In colder areas like on the mountain, squirrels will often live underground in the winter, where it is warmer and where the pantry, dinner table, and bedroom can all be close together.  

Squirrels leave many other less common signs as well. Searching for something rare can be a lot of fun. Birders are known for creating “life lists” of all the bird species they have ever seen. Trackers, too, enjoy the search, but with us it's not new species we are looking for, but rare and unusual evidence of the species we know are here.

These less common signs help tell a more complete story of a squirrel’s life. For instance, do squirrels eat anything besides cones? This is an important question because knowing what an animal eats gives you a lot of insight into their behavior, since most animals spend the majority of their time eating, hunting, collecting, or storing food. Many of the following photos come from the excellent collection by Tracking Leader Kimber Nelson.

Bark is a staple of many herbivorous animals, as shown in the pictures below.

A pine tree with several galls on its branches. Photo: Kimber Nelson.

Detail of squirrel feeding sign on a pine gall. Photo: Kimber Nelson.

In the pictures above, a squirrel has fed on the bark of a gall, an unusual growth created by an insect living inside the tree, that apparently has much tastier bark than the rest of the tree.​ If you look closely, you can see teeth marks left by the squirrel’s front teeth, the incisors.  All rodents and rabbits have two pairs of wide incisor teeth. To narrow down whodunit, look at the size of the teeth marks.

​Squirrels also eat mushrooms,

Squirrel feeding sign on a mushroom. Photo: Kimber Nelson.

​Nip off the ends of twigs to get at the developing pollen cones,

Squirrel feeding sign on a developing pollen cone.

​Dig up truffles,

Sign of where a squirrel has dug up a truffle.

Sign from a squirrel eating a truffle on a log. Photo: Kimber Nelson.

And gnaw on bones to get calcium.

Squirrel feeding sign on a bone. This is an important way for many wildlife to get calcium in their diet. Photo: Kimber Nelson.

Similar to Graham's story above, on one of my more memorable hikes, I was walking along by myself when suddenly, out of the blue, a bone fell from the sky and landed right in front of me. Well, not the sky, exactly. I immediately heard a Douglas squirrel yelling at me as it ran away. I probably scared it right in the middle of its meal!  

Still on the subject of food, the following picture shows another important consideration a squirrel has in its life:

The tail of what was once likely a flying squirrel. Photo: Kimber Nelson.

​The picture above was found in Mt. Hood National Forest and likely shows a tail that once belonged to a flying squirrel. Squirrels are small and are food for many different carnivores. The tail contains very little meat and lots of hair and bone and is often discarded by smaller predators such as owls.

Squirrel Tracks

Squirrel tracks can be difficult to find because squirrels are much too lightweight to make tracks in the grass, mulch, and vegetation that typically covers a backyard. All of the track pictures I have are either in snow or in sand along the beach.

A typical presentation of squirrel tracks in snow.

Just like with looking for unusual sign, a tracker also searches for rare tracks. A tracker's search for something rare happens with tracks as well. Clear tracks are some of those that can be very rare and hard to find.  

​Here is a picture of some of the clearest squirrel tracks I have ever seen, taken by Tracking Leader Garth Olsen on a Wolverine Tracking Project tracking survey trip on Mt Hood.

Very clear squirrel tracks in snow. Photo: Garth Olsen.

​And here’s another from his collection:

Again, very clear squirrel tracks, this time in mud. Photo: Garth Olsen.

​These pictures are amazing because you can very clearly see all the details of the feet – the toes, heel pads, and claws. The front feet are the ones on the bottom, they have 4 toes and two additional pads behind the palm. The hind feet, on top, have 5 toes, with the middle three toes parallel to each other and the inner and outer toes sticking out to the sides.

Like sign, looking at tracks can also tell you about the animal that made them. It’s easier to see patterns when you compare a thing with something else, so let’s compare squirrel tracks with dog tracks.

Squirrel track in thin snow on a branch.

Dog track in wet sand.

First, look at the claws. Squirrels’ claws are thin and narrow, which means they are sharp, adapted for climbing trees. Dogs’ claws show up much larger in the tracks because they are blunter. Also look at the length of the toes. Squirrels have long toes, which helps them grasp objects - which gives a clue as to how they eat.

A squirrel stands on their hind legs and grasps their food in its front feet to eat. Captured by one of our wildlife cameras on Mt. Hood.

When looking at tracks, we can also zoom out to look at where they are found. I’ve found that squirrel tracks often go back and forth repeatedly between trees, like the following picture:

Several squirrel trails go back and forth between two trees.

Or cluster around the base of a tree, like this:

Squirrel tracks in snow clustered around the base of a tree. Photo: Paul Schertz.

I’ve seldom seen a trail that goes very far before ending at a tree. Trees seem to be a theme when it comes to tree squirrels!  

As trackers, part of the search for interesting tracks also includes tracks in unusual locations. Here’s some squirrel tracks – on the tree itself!  

Squirrel tracks in snow and on the base of the tree trunk. Photo: Maggie Starr.

The pattern of footprints also tells you a lot about the animal. Below is the typical trail pattern of squirrels, which speaks a lot to their vulnerability as prey:

Typical squirrel trail pattern. Photo: Paul Schertz.

The pattern shows groups of four feet separated by large spaces in between. This pattern comes from a “body scissors” motion where the spine flexes then contracts with each jump. This is a much faster way of moving than walking, where all of the motion comes just from the legs. Dogs do this type of movement, too, but with them it’s called a gallop and is only done when they are going fast; normally, dogs will walk and trot.  With squirrels, this bounding motion is their usual gait and the way their bodies are shaped, with large, powerful rear legs, makes it an energy efficient way for them to travel.   

Here’s a close up of one set of prints:

Detail of a set of prints left by a squirrel in snow. All four feet are shown. Photo: Paul Schertz.

The hips and hind legs of a squirrel are larger than their shoulders and front legs (if you can’t picture that, look again at one of the squirrel pictures above), so, likewise, their rear tracks are larger and spaced wider apart than their front tracks. Looking again at the picture, that means that the hind feet are actually landing ahead of the front feet. This is a gait designed for speed!

The two pictures below, taken from our wildlife camera on Mt Hood, show how the body contracts and extends as a squirrel moves.

The movements of two squirrels bounding through snow can be seen in the comparison of the top and bottom photos. Captured by one of our wildlife cameras on Mt. Hood.

As prey for numerous predators, this locomotion is important for giving squirrels a fighting chance. 

​And here’s another example of how squirrels are good at escaping predators - by staying hidden:

A squirrel hides from a human on the other side of a tree. Photo: Garth Olsen.

For such a "common" animal, there is lot that squirrels can teach us! If you really want to hone your powers of observation, though, start searching for squirrel scat. Scat can be more difficult to find than tracks and other types of sign. This might be the ultimate challenge for the squirrel tracker!

Detail of squirrel scat left on a log.

Squirrels tend to leave their scat on logs and other routes that they travel on repeatedly, so this treasure hunt will really teach you a lot about their travel routes and how they utilize a landscape.

Now that you have some examples of the tracks and sign that squirrels can leave behind, I hope you are inspired and excited to go out and look at the natural world with fresh eyes. Squirrels can be found almost everywhere, and although the tracks and sign can seem elusive, finding these traces of their presence can be a very rewarding adventure, and one that you can do in almost any environment - whether your backyard, park, or even the forest.

As always, send us your photos, any questions, and your stories as you head out and explore. 

Happy tracking!