Winter Spatial Relationships of Wolves and Coyotes in Riding Mountain National Park, Manitoba

1. What they did

Earlier studies elsewhere found that coyotes tend to live outside areas where wolves are most active, which suggested coyotes avoid wolves. In Riding Mountain National Park, Manitoba, coyotes live entirely inside wolf territories and often follow wolf tracks through snow. The author asked whether, in winter, coyote movements were random relative to wolves, drawn towards wolf areas, or away from them. The author expected coyotes to avoid active wolf areas.

From 1982 to 1986 the author snow tracked wolves and coyotes inside four wolf territories:

• Choosing trails. Canid trails were picked haphazardly. Each tracking session covered 5 km, divided into 100 m units, measured by pedometer or odometer.
• Reading the tracks. Only fresh tracks (0 to 2 days after snowfall) were used. Each unit was classed as wolf only, coyote only, wolf on coyote, or coyote on wolf. Where both species had used a trail, overlapping prints showed which came first and which way each was travelling, so it was possible to tell whether the second animal followed the first or backtracked it.
• Trail meetings. Where one animal’s trail met another’s, the author recorded whether the arriving animal ignored the trail (crossed and carried on), followed it, backtracked it, or avoided it (turned away without crossing or running alongside).
• Snow conditions. Routes with more than 20 cm of accumulated snow (new trails) and routes with a definite path and less than 20 cm of snow (established trails) were recorded separately.

In 1982 to 1984, coyotes were also followed by radio telemetry from the air and the ground.

2. What they found

Shared trails

• The author tracked 535 km and examined 690 trail meetings.
• Wolf-only tracks were the most common category (34%). Both species had used 44% of track segments.
• Of the shared segments, coyotes following wolves was the most common pattern in all four winters (43%). Coyotes backtracking wolves came second, about half as often.
• Wolves followed and backtracked coyotes about equally often.
• Track patterns did not depend on wolf pack size or on which species had made the trail. New and established trails differed in the mix of patterns, so they were analysed separately.

When trails met

• Coyotes kept their original direction at only 10% of wolf trails. They followed the wolves at 98 of 225 meetings, backtracked at 50, and turned away at 54.
• Wolves ignored coyote trails 68% of the time and kept their course. When they did use a coyote trail (29%), they tended to follow the coyote.
• Once on another species’ trail, both species tended to go the same way as the animal ahead. Coyotes that did not use a wolf trail tended to avoid it rather than cross it.

Other observations

• Resting coyotes were seen within 150 m of wolves nine times, and single coyotes were seen following wolves seven times, always more than 100 m behind.
• Coyotes scavenged at or near wolf dens (3 times) and rendezvous sites (5 times). Once, two coyotes fed on elk and beaver carrion near a den while an adult male wolf and four pups rested less than 100 m away.
• Coyotes followed wolves straight to wolf-killed ungulates 36 times, and all 198 wolf kills examined were scavenged by coyotes within 24 hours of the wolves leaving.
• No aggression was seen, but 23 coyotes killed by wolves were found (7 females, 16 males; 20 under a year old). None was eaten. Eleven were within 200 m of kills, and 14 were on snowmobile trails. Pursuits averaged under 5 m (17 cases), and the tracks suggested most coyotes were taken by surprise. None was found while tracking wolves that were following coyotes.

3. What they concluded

• Coyote movements in winter were not random relative to wolves. The two species used the same travel routes, often only minutes apart, and showed no detectable spatial segregation.
• Coyotes did not try to avoid wolves and may have been drawn to areas where wolves were active. Wolves did not seem to change their movements because of coyotes.
• Following wolves appears to be a useful foraging strategy for coyotes, who get most of their food by scavenging wolf kills. It could be learned, since each carcass found rewards the coyote.
• Coyotes chose to follow rather than backtrack wolves, perhaps because fresh kills offer more food, easier and more nutritious portions, and a chance to arrive before rival coyotes and other scavengers.
• Wolves sometimes killed coyotes, but there was no sign that they hunted them. The author suggests wolves killed coyotes only opportunistically.

4. How tracking was or was not used

Snow tracking was the main method. The author recorded fresh wolf and coyote tracks over 535 km, and read overlapping prints to work out which species had passed first and in which direction each was travelling. The author also interpreted how animals reacted where trails met (following, backtracking, crossing or avoiding). Where wolves had killed coyotes, pursuit distances were recorded (averaging under 5 m), and tracking evidence suggested most coyotes were taken by surprise. The paper also reports 36 times that coyotes followed wolves directly to wolf-killed ungulates, without saying how this was seen. Wolf kills were examined in the field for coyote scavenging.

5. Tracker or observer certification

Not reported. The paper does not say who did the snow tracking or how their skill was judged, although every result rests on reading which set of prints lay on top and the direction of travel.

6. Other technologies, skills or innovations

• Aerial and ground radio telemetry of coyotes (1982 to 1984).
• Pedometer and odometer to measure distances tracked.