What Goes In Comes Out

A big part of understanding animal lives is knowing what they eat. There’s lots of general information available in books and other publications, but to understand the dietary habits of the animals in one’s own landscape requires a few steps beyond that. We can observe animals when they’re hunting or feeding, and we can interpret chews, feeding sites, and feeding leftovers. But for many mammals, especially omnivores and carnivores, scat is the best tool. Scat contains the undigestible parts of everything an animal ingests, and it remains long after the creature has left the scene.

For herbivores, plant fibers make up the bulk of eliminations, so their scat has a grainy texture like the rabbit scat shown below. When herbivores eat foods high in water content their scat may be darker and softer, but the fibrous essence can still be seen.

Raccoons are omnivores, and their latrines often contain scats with a variety of contents. In the next photo you see raccoon scats with grape seeds and skins, apple seeds, ant parts, deer hairs, and the amorphous remains of deer flesh. An important safety note: raccoon scat may contain the eggs of a parasite that can infect humans, so it should never be touched with bare hands. To be on the safe side, it’s best to use sticks or other tools to manipulate scat, no matter whose it is.

The photo below shows river otter scat filled with crayfish shell fragments. In locations where fish are the main prey item, fish scales and bones will be the most common contents. In coastal marshes scats with crab shell fragments may predominate, indicating that crabs make up the bulk of the animals’ diet.

For many omnivores and carnivores scat contents vary with the changing seasons. The bear scat shown below was photographed in early May, and it’s made up of the remains of the newly emerging leaves and shoots the bear had been eating. Bears lose weight during hibernation and for many weeks afterwards because the grasses, sedges, and young shoots they must subsist on are energy-poor foods.

It’s only when higher quality edibles become abundant that bears begin to put on the pounds. The bear that left the scat shown in the next illustration had been feasting on black cherries. The summer diet of fruits and berries is often supplemented with insects, and you may find bear scats containing ant or yellowjacket parts.

Scats like that pictured below, full of fragments of acorns and hickory nuts, begin to show up in late summer. The seasonal abundance of acorns, nuts, and fruits, as well as increasing insect populations, provides a crucial, energy dense diet. At this time bears transition into a period of hyperphagia, and spend most of their waking hours seeking food or eating. The fat stores they put on will carry them through their winter hibernation.

The scat of canids reveals that their diets also follow seasonal cycles. Winter and early spring fare is mostly made up of animal prey and carrion. Signs of feeding on deer carcasses start to show up during the fall hunting season and continue through the winter. The coyote scat in the photo below contains deer hair and leg bone fragments. Foxes also feed on deer carcasses, but they aren’t powerful enough to crack large bones to get at the marrow the way coyotes do. Deer killed by hunters (and the carcasses resulting from the vehicle collisions that seem to spike during hunting season) may be preserved well enough in the cold to last through most of the winter. Carcasses of winter-killed deer also provide scavenging opportunities.

The red fox scat shown below (photographed in mid-March) contains the remains of a small rodent that was swallowed whole. There’s a leg bone in the chunk at the lower left, a molar in the piece at the top, and an incisor in the segment at the lower right. The bones are embedded in twisted masses of short hairs. Positioning its scat on the manhole cover was the fox’s way of signaling its presence to other foxes in the area. Small rodents and other small mammals are a winter mainstay for foxes and coyotes.

Like bears, canines graduate to summer foods as they become available. A sure sign that berries are in season are finds like the coyote scat shown below, filled with raspberry seeds. Note that the segments are tubular and blunt-ended rather than tapered like scats made up of animal remains.

As summer progresses, the menu widens. The red fox scat in the next photo (found in early September) contains acorn shells, apple skins, and fragments of field corn kernels.

Some scats lead to surprising discoveries. The next photo shows some gray fox scat containing the remains of a frog. Hollow leg bones are clearly visible, and when I pulled it apart I saw the still articulated bones of a rear foot. It’s a bit unusual to find frog remains in fox scat, but the really surprising thing is that I found this in early December. The weather had been mild, and apparently some frogs had not yet gone underground for the winter.

Food is central to survival, and scat can provide direct information about what animals eat and when they eat it. The many stories scat has to tell can illuminate not just feeding habits, but also interactions among animals, and interactions with the surrounding landscape. Each story adds to our connection with the animals around us.

When Trails Cross

Was the fox afraid of the fisher? Did the coyote chase the rabbit? Questions like these often come up when we find animal trails that intersect. And as always, the tracks tell the story. In the photo below a coyote trotted along a forest road, the direction of travel from upper left to lower right. A rabbit bounded across the road, leaving a trail heading from right to left. Both trails had been made early on a cold morning, and I came upon them not long afterwards. Neither trail showed any changes in pattern or speed in the vicinity of the intersection (although the rabbit took a few slow hops as it entered the road). The tracks in the photo tell us that whichever animal came second, it wasn’t alarmed or excited by the trail it was crossing.

Here’s another example: A coyote had trotted from upper right to lower left, and at least a day later a fisher loped from lower right to upper left across the coyote’s trail. The unchanging pattern of the fisher trail tells us that it had no apparent reaction to the older coyote trail.

In the next photo you see another instance of a fisher crossing a coyote trail. The coyote was trotting towards the upper right, and the fisher loped from right to left. But this time the tracks near the intersection reveal a definite reaction on the part of the fisher. The change in rhythm and the extra tracks tell us that the fisher was very interested in the coyote trail.

Parsing out all those extra tracks is tricky, but you can see my interpretation of the encounter in the next photo, a close-up in which I’ve labelled the tracks. The coyote trail is a nearly straight sequence of tracks on a rough diagonal from lower left to upper right, and its tracks are marked as CL F+H, CR F+H, etc. The fisher tracks are labelled RH, LH etc. Starting at the lower right there’s a right rear track from the fisher’s loping approach, and to the left of that track there’s a group of five prints. Four of those tracks make up a shortened lope pattern and the fifth sits above them and points toward the eventual continuation of the fisher’s journey. The tracks closest to the coyote trail show how the fisher paused and did a thorough examination. Apparently satisfied with its inspection, the fisher continued loping in the original direction.

Why was the fisher so interested in the coyote trail? A coyote would represent a danger to a fisher. A fight between the two could cause the fisher’s death and also pose needless risk for the coyote. But encounters between predators rarely happen because they keep tabs on each other’s movements. The tracks would have revealed the identity and nearness of the coyote, and the fisher apparently decided that it wasn’t in any danger.

I found the coyote tracks in the next photo on a sunny morning following an overnight snowfall. I must have been there not long after the coyote came through, since its tracks didn’t show any signs of melting. The coyote walked from right to left, changing its direction as it crossed an otter trail (which also showed no signs of melting) but otherwise taking little notice of the mustelid’s slide.

I continued to follow the coyote trail and soon came upon a spot (shown in the next photo) where the animal had encountered several pheasant trails. The pheasants had been there earlier in the morning before the sun had risen above the distant trees. The snow would have been several inches deeper, and the pheasants would have dragged their feet through it. Once the sun rose higher it began to melt the snow. By the time I came along the depth of the snow had been reduced and the pheasant tracks had been transformed into a series of pits connected by a raised, wavy ridge. How did this happen? Disturbances created by footfalls create slightly denser snow around–and between, if the feet drag–tracks, and denser snow melts more slowly than undisturbed snow. The compacted snow around and between the pheasant prints sank down more slowly and was transformed into the raised ridge. The coyote came along shortly before my passage, so its tracks hadn’t been exposed to the sun for very long and were unaltered. As the coyote investigated the pheasant tracks it left a jumble of prints, but it probably decided the birds were already far away and not worth pursuing.

So why did the coyote react differently to the two trails it crossed? The otter trail was more recent, judging by the lack of alteration, but a powerful animal like an otter would not have been seen as potential prey by a coyote. A pheasant, on the other hand, would provide a welcome meal for a hungry predator.

Signs of interaction when creatures cross paths may not be as obvious as the examples I’ve described above. You might just see a lighter track a little to the side, made as an animal paused before continuing on. Or differences in speed or gait may reveal an awareness of the recent presence of another creature. Whatever the reaction, it will always be transmitted through the animal’s feet and written in its tracks. Reading those tracks opens a window into the life of that animal.