I found a bobcat scratching post a while back, in a remote ravine off one of the fingers of Drakes Estero. The deep willow thicket was near a small pond with a lot of mixed habitat, so I thought it would be interesting to put a trail camera on it.
Bobcats, like house cats, regularly renew the tips of their claws on logs and tree trunks, but these scratching posts are rare to find. They are startling to come upon: a log or tree trunk, usually in a deep canyon, vigorously scratched and shredded. It’s the kind of thing that can raise the hair on your neck, but it is just the work of a small cat tending to its own business.
Deer make similar scratches on willows and alders when they are rubbing their antlers and practicing for the rut in late summer, but the bark from a deer rub is usually shredded up and down, with rounded ends from the antler tips. A bobcat mark has very sharp scratches, all downward and deeper into the wood, and sometimes has identifiable bits of claw tips.
Both types of scratching have the secondary purpose of leaving scent—claiming the spot and informing other animals of the maker’s presence. Both a buck and a cat will rub the bark shreds with their cheeks and jawbones to leave their scent story. Similarly, coyotes mark territory by scratching the ground with both their front and back feet, leaving scent from foot glands in the roughed-up ground. Many animals leave urine deposits on roughed-up materials.
I left my camera on this bobcat post for a couple of years, and it taught me about a completely invisible aspect of animal life. As the months went by, I captured many fine images of the bobcat, sometimes scratching vigorously, sometimes napping next to the post, and coming and going regularly. It was a female who stayed close to home and hunted regular daily routes. Males, on the other hand, might disappear for weeks at a time to roam a wider territory.
What I didn’t expect was the number of other animals that routinely checked the post. Over the months, I accumulated photos of a coyote mother and her pups, and a male coyote or two, coming up to the post, sniffing, rubbing their cheeks and thoroughly scratching up the ground. Does came right to the knob, rubbing and sniffing, while the bucks would scratch and rub the willows at the outer edges of the thicket. Otters occasionally wandered through, and they, too, stopped to check out the knob and roll around in the leaf litter.
At night, woodrats and mice ran all over the branches and trunks, occasionally stopping at the same knob to smell it and, I presume, leave their own small scent marks. Day and night, skunks and raccoons would show up, prowling and sniffing around. Once in a while, an opossum passed by. During the day, brush rabbits hopped back and forth in the same leafy debris, and a variety of birds—quail, towhees, scrub jays, flickers and sparrows—landed by the knob or foraged on the ground below it. A constant parade of animals was checking out the bulletin board.
I never caught two different animals in any one photo, and it dawned on me that all these animals were keeping track of each other through their scent marks and other signs. They were telling each other what their schedules and activities were so they could avoid unpleasant confrontations. All these animals live in and around the willow gulch as a community. Though predator and prey, they are neighbors, and an important part of community is respect and a desire to avoid conflict. Everyone simply wants to go their own way, fitting in as they do, finding enough to eat while avoiding being eaten. Letting the neighbors know what they are up to seems to be an important part of their strategy.
Scent marking is frequent and universal in the animal world. The landscape is covered with marks, and there are many ways that animals leave them: by rubbing cheek, foot and other glands on a variety of surfaces; by chewing and leaving saliva scents on trees, shrubs and grasses; by urine marking in a variety of ways and locations; by scat placement; and with scratches. Different animals prioritize different methods and locations. It all depends on the animal and the purpose, but the remarkable thing is how universal scent marking is and how much information it conveys.
Scent marks commonly delineate territorial claims, but also, as the bulletin board revealed, daily schedules and more. Animals are constantly telling their story, communicating with their own species and others, with friends and with foes. Their chemical signatures carry highly detailed information about their health status, reproductive cycles, current diet, current hunting and foraging areas, social status and dominance, preferred travel routes and, well, who knows what else. Maybe simply how they are feeling that day. It is almost like they are filling out scheduling forms and sharing them with each other.
Research has indicated that a black bear may have a sense of smell 10,000 times better than our own. What can that possibly mean? Other animals have varying powers of smell, and almost all are far beyond our human sense. It is impossible to imagine what that bear can tell about the world with a sense that sharp. Similarly, researchers also recently discovered that an elephant can feel and interpret ground vibrations, or surface waves, from the footfalls of another elephant several miles away. A sea lion can feel (with its whiskers) pressure waves from an individual fish 100 feet away.
Animals have sensory capacities that build a picture of the world in startling detail. Whether it is a gopher patrolling its 30-foot circle of tunnels or a coyote trotting through miles of open hills, the world an animal moves in is filled with scent information that helps it navigate toward what it needs and avoid things that threaten it.
Tracking and reading the subtle signs that animals leave opens the world of animal communication and helps explain much of their behavior. But I often wonder what it would be like if I could invent a “smellometer helmet” and walk around in the woods smelling everything a coyote or fox can smell. It would be overwhelming! Close visual observation in tracker-mode is nearly as overwhelming in its power to reveal the invisible. It may be that our species traded our scent acuity for our ability to process visual information at an equally high level.
Richard Vacha is a Point Reyes Station resident and the founder of the Point Reyes Tracking School and the Marin Tracking Club. He visits the bobcat scratching post infrequently, and he moves quietly when he does.