Congratulations to Rinky for being the first person to correctly identify that a Black Bear had been rubbing its back side against a utility pole in Monday’s Mystery Photo! A vast majority of responses were correct! Because of the relatively warm fall we’ve had and the ample food supply, Black Bears are still active in much of northern New England. There is a limited amount of time when bears are awake and snow is on the ground, allowing you to see what they’ve been up to. This year they are still feeding fast and furiously and, as the tracks in the snow confirm, scent marking.
Black Bears of all ages and both sexes engage in scent marking – rubbing their scent on trees and telephone poles (as well as biting and scratching them) that are often located along travel corridors. Scent marking typically occurs during the breeding season in June, when males, especially, announce their presence by standing with their back to a tree or pole (often one that leans) and rub their shoulders, neck and back against it, leaving their scent.
The tracks in Monday’s Mystery Photo were discovered recently at the base of a utility pole in New Hampshire. One look at the tracks’ position, pointing away from the pole, tells you that the bear that made them was facing away from the pole and rubbing his back side against it – proof that scent marking is not limited to the breeding season. (Photo: Black Bear scent marking the same pole in mating season, taken by Alfred Balch)
(If you are feeding birds, it would be wise to bring your feeders in at night until we’ve had enough cold weather to drive Black Bears into hibernation.)
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When your quest is to find out as much as you can about the identity, activity, diet and territory of your four-footed neighbors, it is logical to make the most of all your senses. Tracks can be seen, scrapings and bite marks on a tree can be felt and yes, one’s sense of smell can enhance any tracking expedition. Just as the tracks and scat of different species of animals have distinctive characteristics, so does the urine of different animals. Scent marking, including urination, is a behaviour used by animals to identify their territory, and therefore a highly visible sign in winter.
At this time of year, foxes are breeding, and without even putting your nose near where a fox has marked his territory with urine, you can detect its skunk-like odor as you pass by. If you’re so inclined (and I realize many readers may not be) you can heighten your sensory experience as well as your identification prowess by sampling the smell of other animals’ liquid waste. White-tailed deer urine has a pungent, piney smell, quite pleasing to this naturalist’s olfactory receptors. You can detect a porcupine den from a considerable distance by the pungent, very distinctive but hard to describe odor of its urine (which spills out onto and coats the bark of a tree den, thereby advertising the porcupine’s presence). Coyote urine smells very much like a domestic dog’s, and members of the weasel family often have musky-smelling urine, though a recently-sniffed fisher marking had very little scent.
Needless to say, it’s a lot easier to discover and sample urine when there’s snow on the ground and it is more evident. Virginia opossums, snowshoe hares, red and gray squirrels, eastern coyotes, red and gray foxes, raccoons, fishers, mink and striped skunks are all in or entering their breeding seasons, when scent marking is more frequent. Snow is currently on the ground, at least in northern New England. It’s prime time for olfactory activity, if you’re game. (Photo: stump marked by a red fox)
Foxes, like all canids, tend to mark their territories frequently with both scat and urine. Both convey information to other foxes regarding hierarchy and sexual status, in addition to marking territory. As these Gray Fox tracks crossing a pond illustrate, it’s rare for an elevated object in a fox’s line of view not to be visited and anointed. Research shows that when scavenging, foxes urinate up to 70 times an hour, allowing just a small amount of urine to be left in any one place. In addition to rocks, stumps and other raised objects, the remains of a meal are often urinated on, indicating that the nourishing portions have already been consumed.
Red Foxes are generally solitary animals, except during their courtship period, which occurs any time between December and February. At this time mates pair up, so it is not unusual to see two sets of fox tracks together. This is also the time of year when the males’ urine acquires a strongly pungent, skunk-like odor detectable from hundreds of yards away.
Female coyotes have one heat, or estrus, a year, sometime between January and March. As the time approaches, mating pairs scent-mark in tandem. The female urinates and then the male usually follows suit and urinates adjacent to it. After mating, the reverse takes place, with males often urinating first and the females adding their scent afterwards.
Once estrus arrives, drops of blood are often evident in the female’s urine, but scent-marking isn’t the only place you see evidence of estrus. If you come upon a coyote bed in the snow this time of year, inspect it closely — the females’ beds often will have drops of blood in or near them (see photo). A recent discovery of a group of five coyote beds showed evidence that at least two of the beds had been occupied by adult females in estrus.
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Scent-marking plays an important communication role in the animal world. A variety of species use glandular secretions to convey (for some distance) messages. From beavers spreading castoreum on scent mounds to fishers leaving their scent every time their hind feet touch the ground, the woods are alive with messages often undetected by most humans. Some of these are left by White-tailed Deer, which have two primary scent-marking behaviors: antler rubbing and scrapes.
One used to associate an antler rub with the act of a buck removing drying velvet from its antlers. However, it turns out that very few rubs are made by deer removing antler velvet, a process that’s normally completed within 24 hours. Instead, most rubs are made by relatively few dominant bucks to signal their readiness to breed and to mark their territory.
All White-tailed Deer possess specialized forehead glands that become increasingly active in autumn, particularly in adult males. All bucks spread their scent by rubbing their foreheads (which contain specialized scent glands) against trees and shrubs that have smooth bark, few, if any, lower limbs and are ½” to 4” in diameter. (Older bucks also will rub trees six or more inches in diameter.) In the Northeast, Trembling Aspen, Staghorn Sumac, Red Maple, and willows are often used for this purpose.
Mature, socially high-ranking bucks exude greater amounts of the glandular secretion than do younger males or females. They begin marking their territory soon after losing velvet and continue marking until they cast their antlers in December or January. The chemical signals left at a rub site tend to suppress the aggressiveness and sex drive of young males. However, those same signals stimulate females. The amount of rubbing an individual buck does depends on the level of testosterone in his blood, which in turn is largely determined by the animal’s age and dominance status.
We may not be able to detect the chemicals on a rub, but it’s hard to miss the sight of the light-colored blazes that magically appear in the woods at this time of year. (Photo: White-tailed Deer rub on Staghorn Sumac. Thanks to Chiho Kaneko and Jeffrey Hamelman for photo op.)
Black Bear males are not shy about making their availability and intentions known to the opposite sex. Their most prevalent means of communicating this information is to leave their scent on trees (as well as other structures, such as telephone poles– see photo) by scratching them with their claws, biting them and rubbing on them with their shoulders, back and neck. Often they will use the same marking tree year after year, with signs accumulating on the tree.
Both males and females mark trees year-round, but at this time of year, at the peak of their mating season, males are especially active markers, in order to convey their social identity, reproductive status and location to female passersby. One might consider such marking trees as ancient “scratch.com” mating sites. If you find one, be sure to look for stray hairs that have been inadvertently left behind. (photo by Alfred Balch)
Fishers are one of the most rewarding mammals to track as they leave so many signs. One of the most common ones, other than their tracks, is their scent posts. This is where a fisher rubs itself, anointing the substrate with its scent as it marks its territory. Young saplings often serve this purpose. The fisher rubs and rolls on a young tree, often a conifer, usually breaking a few branches.
If you see a scraggly-looking sapling in the woods, and there are fisher tracks nearby, examine the sapling closely for fisher hairs that often get caught on the branches when a fisher rubs against them. More often than not, the fisher will also mark the tree with a bit of scat or some urine. Fishers are very adept at controlling the amount of feces they leave, often excreting very small portions as markers throughout their travels.