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Scent Marking: Wolves and Coyotes

Cynthia Roberts

Introduction

Many animals are thought to scent-mark their territories. It is believed that these marks will warn other animals that a particular area already has inhabitants that would not welcome intruders. It is a silent way of avoiding violence between animals that would otherwise be necessary to maintain a territory. Scent-marking can also provide a silent communication between animals that share a territory. It can also help an individual animal keep its bearings when traveling. Two species that are thought to use scent-marking to define their territory and communicate within their group are wolves (Canis lupus) and coyotes (C. latrans).

Wolves

Territorial markers

From 1968-1973, Roger P. Peters and L. David Mech studied several wolf packs that lived in the Superior National Forest of northern Minnesota. These wolf packs kept basically stable territories with rare or nonexistent interpack contact. Peters and Mech studied the various markings that were left by these wolves. They divided the markings into four categories, raised-leg urination (RLU), squat urination (SQU), scratching, and scats. Since squat urination and scats are primarily eliminative in nature, it is probable that they are indirect scent marks. Scratching is primarily a visual mark, but it is possible that it also carries a scented message through glands in the pads of the feet.

Peters and Mech tracked these wolves and recorded where the various scent marks were left. Most RLUs were left on roads and trails that were on the edge of the territories. Some were left in the brush and on frozen waterways. Most of the RLUs were deposited on objects. This practice allows the mark to be better distributed. It also allows the urine to act as a visual cue. Positive feedback seems to be the primary stimulus in causing a wolf to remark an area. A wolf was more likely to renew his own recent marks than those left previously by itself or another wolf.

Loners and pair-bond formation

From 1975-1977, Russell J. Rothman and L. David Mech studied wolves in the Superior National Forest in northern Minnesota as well as captive wolves. They studied the location of marks as well as the body position used when leaving the marks. Lone wolves did not mark with RLUs. They also did not leave marks of any kind near kills or on top of other marks. They marked less on roads and trails than did resident packs. A high level of RLUs occurs when two loners meet. It is possible that a pair bond will form when two loners of the opposite sex meet. In newly formed, pairs there is a high rate of RLUs. This rate decreases with the amount of time the pair remains together until it reaches a base rate. Wolf pairs cease to RLU when they have been separated. Breeding pairs have an increase in RLUs and SQUs during the breeding season. It is possible that the hormonal changes due to the social stimulation of courtship might cause the onset and frequency of scent-marking. This increase may be due to the necessity of pair synchrony for successful breeding.

Coyotes

Territorial marking

From 1974-1876, W. Don Bowen and Ian McTaggart Cowan studied coyotes in Jasper National. They recorded six different types of scent marks, urine alone; urine and scratching; urine, feces, and scratching; feces alone; urine and feces; and feces and scratching. The two scent marks most frequently used were urine alone and urine with scratching. The urine was usually deposited on objects to allow for the distribution of the scent. This practice also allows the urine to act as a visual mark. The coyotes left most of their marks on the borders of their territories.

Coyotes react strongly to their own scent marks. Increased urine-marking also occurs after aggressive encounters with neighbors or transients. Scent marks do seem to dissuade neighboring packs from entering each other's territories, but it does not provide an impenetrable border. Coyotes will cross territorial borders to feed off carcasses that lie near the border. However, they will not mark or eliminate near the carcass. They also react strongly to disturbances, such as birds making noise in a nearby tree.

Wolves and Coyotes

Territorial marking

From 1982-1986, Paquet studied wolves and coyotes in Riding Mountain National Park. Various trails were studied. Some of them were used by wolves or coyotes. Others were used by both. Both species marked roads and trails more than the brush and frozen waterways. The frequency of marks increased with the size of the pack. This increase is consistent with previous coyote data, but inconsistent with previous wolf data. Both wolves and coyotes responded to the presence of the other species with increased marking. Coyotes reacted actively by overmarking scent marks left by wolves. The wolves' reaction was more passive. They investigated the coyote marks and occasionally overmarked them. Conclusion

Wolves

Wolves use scent-marking, through raised-leg urination and other marks, for a variety of communications. The alpha male is the primary RLU scent-marker with occasional instances of other wolves using RLUs. Wolves mark the borders of their territories with RLUs. These scent marks stop other wolves from entering the area. RLUs also provide a scented map for wolves as they travel through their own territory. During times when the pack temporarily separates, scent marks, such as SQUs and scats, provide information about which portion of the territory has been hunted. Lone wolves do not leave scent marks because they do not want to attract the attention of resident packs. When two loners of the opposite sex meet, they use scent marks in the form of RLUs and SQUs to communicate. In breeding pairs, scent marks provide a method of establishing synchrony. In packs, scent-marking communicates dominance.

Coyotes

Coyotes use scent marks to communicate. Urine is used as the primary marker. Coyote urine contains such information as the gender, dominance status, and breeding status of the coyote. All coyotes within a pack use scent marks. However, the dominant male marks more frequently than the rest of the pack. Scent marks are used to define the borders of a pack's territory, but they do not prevent other packs from entering the area. However, an intruding pack enters a resident pack's territory with caution, and they do so only when the temptation is too great to pass. Lone coyotes do not scent mark. Loners do not want to attract the attention of resident pairs or packs. Juvenile coyotes who have been temporarily separated from their pack will scent-mark as though they were still traveling with the pack.

References

ASA, C.S., MECH, L.D., SEAL, U.S., and PLOTKA, E.D. (1990). The influence of social and endocrine factors on urine-marking by captive wolves (Canis lupus). Horm. Behav. 24: 497-509.

BARRETTE, C., and MESSIER, F., (1980). Scent-marking in free-ranging coyotes, Canis latrans. Anim. Behav. 28: 814-819.

BOWEN, W.D., and COWEN, I. McT. (1980). Scent marking in coyotes. Can. J. Zool. 58: 473-480.

LEWIS, M.A., and MURRAY, J.D. (1993). Modelling territorality and wolf-deer interactions. Nature. 366:738-740.

PAQUET, P.C. (1991). Scent-marking behavior of sympatric wolves (Canis lupus) and coyotes (C. latrans) in Riding Mountain National Park. Can. J. Zool. 69: 628-637.

PETERS, R.P., and MECH, L.D. (1975). Scent-marking in wolves. Amer. Sci. 63: 628-637

ROTHMAN, R.J., and MECH, L.D. (1979). Scent-marking in lone wolves and newly formed pairs. Anim. Behav. 27: 750-760.