Ever since we entered into the season of water restrictions and wildfires, I’ve found myself pining for the cold, snowy field days of last December. The sky is clear, the air is crisp, and the ground is covered in a crunchy layer of week-old snow. We have hand warmers carefully placed in the toes of our wader booties, hot tea stowed in the side pocket of the truck door, and two pairs of gloves is a must. With temperatures dropping well below zero most nights, icicles form around the metal cases and padlocks that secure the dozens of camera traps we have deployed throughout the watershed. To combat the icicles, I stash a lighter in the front pocket of my waders as we unload the truck and make our way to the first camera station.
As we walk along the snowy bank of a tributary stream, the watershed comes alive with stories of past travels: a herd of elk (Cervus canadensis roosevelti) moving through the riparian, a black bear (Ursus americanus) walking down the bank to a fish-filled stream, a bobcat (Lynx rufus) traveling up a hill into the forest above. These stories are told by the distinctive footprints left behind as these animals move across the snow-covered ground.
We don’t need to look too closely to see that many of these tracks belong to wolves (Canis lupus). Snow can provide good impressions of canid1 tracks, the best ones being found in a thin layer of fluffy flakes (5-20 mm) over a hard base. Generally, those belonging to wolves are robust, measuring about 12 cm long by 9 cm wide, with four symmetrical toes and evident claws (they do not have retractable claws like most cats do). Coyote tracks are similar, but about half that size. Several of our camera traps have confirmed the presence of both canid species in this watershed, but coyote detections have been notably less frequent.
In addition to wolves and coyotes, there is another member of the canid family present in this watershed: the resident labrador retriever. An easy way to differentiate between the wild and domesticated travelers is by looking at the pattern of the trail left behind; wolves tend to travel in a straight line to save energy whereas most domestic dogs leave behind a zig-zag pattern. The gait of a wolf when walking, trotting, or running is seemingly effortless and smooth, unlike the bouncing, loping gait of a well-fed lab.
It is enchanting to follow in the footsteps of the wolves I have seen so many times on the cameras, wondering who exactly the prints belong to. With her graying muzzle and dark bushy tail, the breeding female is very distinguishable from the other wolves and detected most frequently by the cameras. It is exciting to think that some of these footsteps may belong to her.
This wise wolf and her family make up a population that has been suppressed for nearly a century due to lethal management and human persecution. The recolonization and recovery of wolves in this watershed follows the reintroduction of what is now a thriving population of Roosevelt elk, and Indigenous-led efforts are currently enhancing key spawning habitat to support the recovery of Pacific salmon populations. These species not only hold exceptional cultural value, but also serve as important sources of food and nutrition for wildlife, including wolves. Food availability and abundance will play a vital role in the persistence of this newly established wolf pack.
Salmon for wildlife
As the days progress further into December, more and more coho salmon (Oncorhynchus kisutch) are showing up in this stream, and the abundance of tracks back and forth along the riparian’s edge tell us that the wolves and bears are well aware of this.
Lighter in hand, we continue our route to check a camera that was deployed just 14 days ago. Before we can spot the camera, our olfactory cues are triggered and we see the blood in the snow. In hopes of capturing predator activity, this camera targets some of the most pristine spawning habitat in the watershed. As we walk closer, we see the remnants of multiple fish concentrated on a snowy plateau, right off a path to the stream’s shallows. The short path is shaped by large, flat-footed tracks—this is a bear’s fishing spot.
I hold the lighter to the padlock securing the camera. Once the ice has melted enough to get the key inside, I eagerly open the camera to find that a whopping 330 videos have been recorded. I can’t help but squeal with excitement when I hit “playback” and see a portly black bear displayed in thumbnail after thumbnail of each video. Like clockwork, this boar returns to this bountiful spot each night, fishes until dawn, and then goes undetected by the camera during daylight hours.
In coastal British Columbia, researchers have observed bears foraging on adult salmon extensively at night. In part, this may be to avoid competition with other bears, but also the darkness allows them to catch more fish (pdf). During the day, salmon are evasive and attuned to the visual signals of potential predators, but at night they focus on spawning activities, generating auditory cues that bears can exploit. This slow-moving bear is able to exploit this period of vulnerability in salmon by not only switching to nocturnal fishing, but also selecting a fishing spot with a fallen log that basically delivers the fish to him on a silver platter.
Solitary males are the last to enter their dens, but where they are continuously finding food, some bears actually practice a “walking hibernation,” in which their metabolism slows but they continue to move about searching for food. In this watershed, the coho run doesn’t peak until December and fish continue to enter the river to spawn well into January, so it’s likely that this bear will stick around a while longer.
Although black bears do a lot of the heavy lifting when it comes to connecting marine and terrestrial ecosystems, fishing is part of the behavioural repertoire of many other predators in this watershed. As detailed in our last Notes From the Field, we have observed remarkable fishing activity from wolves, grizzly bears, bald eagles, and even those within the felid2 family.
On a crisp December morning, well before sunrise, one of the cameras captured a bobcat taking a cold plunge into the glacier-fed waters, chasing after a coho salmon. To our knowledge, documentation of bobcat fishing behaviour is few and far between. In 1964, Yoakum described the fishing strategies of two captive-raised bobcats who readily took to the water to capture white crappie (Pomoxis annularis) and rainbow trout (Oncorhynchus mykiss) on two different occasions. In 2016, a ranger in Washington’s Olympic National Park recorded what can only be described as an “expert display of fishing prowess”—a bobcat catches a salmon nearly the size of her own body, barely getting wet in the process. Bobcats are opportunistic hunters, exhibiting a wide dietary niche, so it is not uncommon for fish to be part of their diet where available. As we approach another winter, we can only hope that the cameras will capture more rarely seen behaviours; perhaps a cougar (Puma concolor) or coyote (Canis latrans) will be next to plunge a paw or muzzle into the water.
Preparing for another winter
In December, we will check the cameras one last time before the year’s end. Depending on snowfall and access into the watershed, we may not return until spring of next year. This means the cameras will need to be “winterized,” as each one will be equipped with a newly formatted SD card, fresh lithium batteries, and desiccant to absorb moisture and prevent the lens from fogging. At some stations, we will need to also raise the height of the cameras to account for excessive build up of snow. This effort will allow us to continue studying wolves and the many other critters who are active throughout the winter months.
As we continue to document the recolonization and recovery of this wolf population, we aim to further our scientific understanding of human-wolf interactions, including effects of conflicts that result from commercial forestry. Information generated from this long-term project will not only advance our minimally invasive approaches for monitoring wolves, but also inform an Indigenous-led, holistic watershed approach to habitat restoration and conservation.
This work is made possible in part by the support of the Animal Welfare Foundation of Canada.
- Any animal of the dog family Canidae, including wolves, jackals, foxes, coyotes, and the domestic dog. ↩︎
- Any animal of the cat family Felidae, including lions, jaguars, bobcats, cougars, and the house cat. ↩︎
Our annual report is out now!
Get highlights from the year, our science, flagship projects, staff and volunteers, as well as a peek at what’s in store for the coming year.