Winter season review

We can't believe it- our winter survey season is all wrapped up! It's been a wonderful season, chock-full of interesting wildlife findings and ​fun times! We want to extend a big thank you to all our amazing volunteers, without whom none of this would be possible! Winter wildlife surveys are hard work- volunteers spent the winter trekking through snow, braving winter weather and Timberline traffic to collect valuable camera and tracking data!

This season trackers completed 14 tracking surveys, and surveyed over 14 miles on Mt.Hood! Our Winter Tracking Survey season ended in March and will resume as the snow returns to the mountain next December. In the meantime, our summer Scat Surveys will take over the search for target species sign and genetic sample collection! 

Camera crews monitored 19 cameras this winter on Mt.Hood and in the surrounding forest. We also had an additional 14 camera sites set up and monitored by dedicated volunteers who shared their data with us, for a total of 33 camera sites this season! Our camera surveys are a year-round operation- some camera sites will remain up through the summer season, but many of our cameras will be relocated to sites better suited for summer wildlife activity. 

Target Species

The Wolverine Tracking Project has four primary target species- Sierra Nevada red fox, Gray wolf, Pacific marten and the wolverine (of course!). This season we had several target species detected on trail cameras, as well as some target species tracks and scat findings!

The Sierra Nevada red fox was detected at 3 different camera sites this winter! The Sierra Nevada red fox is found in the Sierra Nevadas of California, the northern California Cascade range and the Oregon Cascades. These elusive fox reside in high montane habitats, and have only been detected at elevations above 4,000 ft in Oregon. In Oregon they have typically been detected near or above the tree-line, with a preference for open areas and forest edges. However, there is some evidence that Sierra Nevada red foxes are seasonal migrants and may move further below the tree line during the winter.

This season we detected red fox at cameras between 4,400 ft and 6,300 ft. The majority of the detections were at camera sites close to or above the tree line, however we had one anomalous detection at a camera site located further below the tree line then we have previously documented. 

From top to bottom: A Sierra Nevada red fox moves through the trees; A trail camera manages to capture just the top of a red fox after they investigate the camera site; A red fox wades through the snow on a foggy day.

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Sierra Nevada red fox have relatively low populations densities- about 1 per square mile. While the size of the Sierra Nevada red fox population in Oregon is not currently known, based on their low population density and the limited availability of subalpine habitat on Mt.Hood, we can assume that their population is fairly small. 

Sierra Nevada red fox have 3 different color phases- red, silver, and cross. In the red phase, they have a reddish brown upper body, with a white chest and belly. The cross phase looks very similar to the red but with a swath of gray along their back. Silver phase foxes are almost entirely black with silver guard hairs. The distinct white tip of their tail is typically present in all 3 color phases!

This season we had several silver phase fox detections and a single cross phase fox detection. It can be difficult to distinguish silver phase individuals based on trail camera photos, so we can only definitively say that we detected two individual foxes this season. 

Along with the camera detections we also had a few potential fox scat collections! Collecting fox scat is an important component of monitoring the Sierra Nevada red fox populations. We send collected fox scat in for genetic analysis- which can help to identify individuals and determine whether our local Sierra Nevada red fox population continues to be genetically distinct from other montane fox populations in our region.

A potential Sierra Nevada red fox scat found at a camera site.

Our other canine target species, the Gray wolf, was not detected on any trail cameras this season. Cascadia Wild has been documenting Gray wolf presence in the Mount Hood survey region since the White River wolf pack was established in 2018, using camera, tracking and scat surveys. 

The White River wolf pack resides primarily on the Warm Springs Reservation, as well as adjacent public and private land. At the end of 2020 the White River pack was estimated to have expanded to nine wolves, including one breeding pair. However, more recent estimates of the population indicate that the pack is down to three wolves, with no reproduction documented in 2021. 

While we did not capture any Gray wolves on camera this season, a camera crew volunteer did come across some super-sized canine tracks that could potentially be from a wolf! 

Potential wolf track in the snow near a camera site.

With our summer Wolf Scat Surveys resuming soon, we hope to find much more evidence of wolf activity in the coming months!

We had several Pacific marten detections this winter at two upper elevation camera sites. Pacific marten rely upon healthy, high elevation conifer forest habitat for hunting and denning. A thriving Pacific marten population is often considered an indicator that the ecosystem as a whole is doing well. 
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From top to bottom: A Pacific marten scurries across the snow and investigates a tree well; A marten pauses as they make their way through the camera site.

In one case, our camera may have missed the marten but caught the tracks! We didn't pick up any Pacific marten at this site the month that this photo was taken, but the tracks in the photo appear to be marten tracks! We had multiple marten detections at this site in the months that followed!

Potential Pacific marten tracks in the snow at a camera site. 

Our namesake target species, the wolverine, has been extirpated from Oregon since the 1930's as a result of excessive trapping and as a by-product of efforts to exterminate wolves. The recovery of regional wolverine populations is further hampered by habitat loss and fragmentation. 
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While we have yet to have any wolverine detections in our survey region, the re-establishment of wolverines in Mt. Rainier National Park (just across the river!) has us feeling hopeful for the future. 

Carnivores

Animals in the order Carnivora range dramatically in size, diet and behavior. From the big cats all the way down to the slinky weasels, our cameras caught all kinds of carnivores this winter! 

The largest felid in our region, the mountain lion, is rarely seen due to their shy and secretive nature. Our camera surveys detected mountain lions at three camera sites this winter, all in the East Forest survey area. These big cats are fierce predators, and primarily eat deer and elk. It may be no coincidence that sizable deer and elk populations were also documented at these locations!

Mountain lions are territorial animals, with large home ranges of up to 100 miles. They spend the majority of their lives on their own, except when mating or rearing kittens. Mothers will remain with their young for up to two and a half years! This winter we had one detection of two mountain lions traveling together- we are not able to identify whether this duo is a breeding pair or a mother and her kitten but we hope to see more of them in the coming months! 

From top to bottom: Two mountain lions lounging at a camera site; A mountain lion strides through a camera site at night; a mountain lion cautiously sniffs at a baited log; a mountain lion makes a quick detour to check out a bait area before continuing on their way. 

Another fierce feline predator, the bobcat was detected at 15 camera sites this winter! Bobcats were detected at sites on Mt.Hood and in the East Forest survey region. Bobcats are significantly smaller than mountain lions, and primarily depredate smaller mammals such as snowshoe hare, squirrels, and birds. 

Our cameras caught bobcats on the move, investigating bait, and sneaking around! For the last photo in this series, keep your eyes on the lower left-hand corner!

From top to bottom: A bobcat posed in the snow; a bobcat climbing a tree to get at the bait; a bobcat investigates a baited tree; a bobcat slinking through the grass. 

It would be unusual (but not unheard of!) for a bobcat to attempt to take down an adult deer. In this footage from a volunteer camera, it certainly appears that this bobcat is stalking the browsing deer but we can't know for sure! 

​Coyotes were detected throughout the winter at camera sites across the elevation gradient! Coyote populations are thriving on Mt.Hood, and these crafty canines are drawn to the hormonal and scent based baits we use to attract our target species. We captured lots of footage of coyotes investigating the bait at our camera sites, and in one instance actually running off with the bait box! 

From top to bottom: A curious coyote cautiously sniffs at the baited tree; A coyote snatches a bait box off the tree it was nailed to; Two coyotes approach a baited log; A coyote sniffs around the snow at a camera site. 

If the coloration of the coyote in the second to last photo above caught your eye- you aren't alone! Melanism is an unusual trait in coyotes and is typically restricted to coyote populations in the Southeast United States. The trait is thought to be the product of past hybridization with wolf populations! 

In addition to our camera detections, volunteers were also able to identify several coyote tracks on group tracking surveys this winter! Coyote tracks were found on five of group tracking surveys that went out! 

A volunteer points to a coyote track in the snow.

Winter is a quiet time for Oregon's black bear population! Although our climate is temperate enough for black bears at lower elevations to remain active year-round, we still don't expect many black bear detections in the coldest months of winter. We had a few black bear detections at lower elevation camera sites from October to November and one surprising December detection! The photo below is our first black bear detection of spring! We look forward to seeing more black bear activity on our trail cameras this summer! 

From top to bottom: A big black bear sniffs around a camera site; A black bear rubbing against a bait box attached to a tree; a bear strolls through a camera site in the fall; a black bear rolling on a bait box buried in snow.

There are two species of skunks in Oregon, striped skunk and spotted skunk. Skunks are typically less active in the winter months, but even so we managed to detect both species! Striped skunks were detected at 11 camera sites. Skunks are nocturnal, so the majority of skunk detections occurred at night. The photo below is one of the few daytime detections we had- it's a treat to see their beautiful striped coats in the light! 

From top to bottom: A striped skunk caught wandering around a camera site in the daylight; a striped skunk sniffing the base of a baited tree. 

The smaller, and more secretive, spotted skunk was only detected at 3 camera sites this winter. The visit below perfectly shows off their adorable polka dots! 

A spotted skunk sniffs around a baited log at a camera site.

We had just one camera detection of everyone's favorite backyard bandit this winter! While most people associate raccoons with urban habitats and trash-can diets, these opportunistic critters also reside in the wild and dine on a variety of natural foods including plants, berries, insects, frogs, eggs and more!

A raccoon clambering over the base of a baited tree.

Trackers also discovered raccoon tracks on a group tracking survey this winter! Raccoon tracks have a distinct trail pattern- often leaving two footprints next to each other, one big and one small. The photo below doesn't show this pattern exactly, but you can clearly make out four of their five dexterous little toes!

Raccoon tracks in the snow.

The smallest of the Carnivora order detected by our wildlife surveys this winter was the weasel! There are two species of weasel in our region- the short-tailed weasel and the long-tailed weasel. The main differences between these species are size and tail length, but sexual dimorphism in both species means that there is some overlap in the size of male short-tailed weasels and female long-tailed weasels! This makes it difficult to distinguish between the species in photos- so we just call them weasels!

A weasel spotted briefly at a winter camera site!

Ungulates

Ungulates are a diverse clade of hoofed-mammals- such as deer, sheep, giraffes, cattle, hippopotamuses, and more! We have two prominent species of ungulates in our region- deer and elk! In the winter season, deer and elk typically migrate to lower elevations to find food and avoid deep winter snow. 

This winter we detected elk at 8 camera sites, all located in the East Forest. While the majority of elk detections were at sites below 3,000 feet, we did have a few elk detections above that in the late fall. In the winter elk live in herds that most often consist of cows and calves, while bull elk travel alone or in small bachelor herds. We detected elk herds traveling through multiple camera sites this winter, sometimes stopping to stay a while!

From top to bottom: A herd of elk runs past a trail camera; An elk feeding at a camera site; a bull elk resting.

Elk scat was discovered by volunteers at camera sites with frequent elk activity, and one lucky volunteer even got to see a herd in the distance as they were heading to their camera! Elk scat was also found on one tracking survey, pictured below. 

Elk scat detection from a winter tracking survey.

Deer have a similar social structure to elk in the winter, although they tend to form smaller groups. This winter we detected deer at all of our East Forest camera sites, and five of the Mt.Hood camera sites. We had one particularly exciting deer detection early in the season, when a buck was seen running through the camera site, pausing briefly before heading out of the frame, closely followed by a coyote! 

From top to bottom: A buck pauses as they run past the trail camera, a coyote is detected shortly afterwards; A buck stops briefly in the snow; A deer captured mid-leap; a deer gazes into the trail camera. 

SMALL MAMMALS

Our forests are full of small mammals- many of whom remain active throughout the winter. Small mammals were frequently detected by our trail cameras, despite the fact that they are designed to target larger species! Small mammals were also frequently detected on tracking surveys this winter- particularly hares and squirrels! 

Snowshoe hare were the most common tracks found on group tracking surveys this season- our trackers documented over 90 snowshoe hare tracks! Snowshoe hares were detected at 11 camera sites this season. 

From top to bottom: A snowshoe hare leaves tracks in the snow around  a camera site; Snowshoe hare tracks found on a tracking survey- the front feet are seen on the right side of the photo, with the hind feet coming together directly in front of them. 

There are several species of squirrels in our region that we see throughout the year, however only a few of them remain active all winter long! Of those, the most frequently detected was the Douglas squirrel. Douglas squirrels were detected at 11 camera sites this winter. Douglas squirrels were detected in both the East Forest survey region and on Mt.Hood. Western gray squirrels were detected at 8 camera sites, but only in the East Forest survey region. This is consistent with those species' habitat ranges- western gray squirrels are primarily found in low-elevation forests while Douglas squirrels inhabit mature, mixed conifer forests across the elevation gradient. Northern flying squirrels also remain active throughout the winter, but were not detected as frequently this winter, potentially because they are nocturnal. We detected Northern flying squirrels at only two camera sites this winter! 

From top to bottom: A Western gray squirrel digging in the snow; A Douglas squirrel with a cone in their mouth; A Northern flying squirrel checking out a bait box. 

Another common squirrel in our region is the California ground squirrel! These squirrels are inactive throughout the winter in our region, but we still had a few detections in the fall and then again in the spring as they begin to reemerge!

California ground squirrels reemerged this spring after a long winters rest!

Squirrel tracks and sign were also frequently detected on our winter tracking surveys! Since our tracking transects are focused on the Mt.Hood survey area, it is likely that the majority of these detections can be attributed to Douglas squirrels. Trackers documented a total of 80 squirrel tracks and 36 squirrel sign this winter!

From top to bottom: Cambium feeding sign documented on a tracking survey; Squirrel tracks in the snow. 

Chipmunks are another species in the family Sciuridae that are generally inactive throughout the winter. We detected chipmunks at four camera sites this season. The detection below, of a chipmunk digging in deep snow, is from this past month- late spring snow storms on the mountain may have taken this chipmunk by surprise! 

A chipmunk digging in the snow.

Finally, the smallest of the small mammals detected this winter- the mouse! Mice were detected at six camera sites, both on Mt.Hood and in the East Forest survey region. By far our best mouse detection came early in the winter, after a storm knocked down a tree branch in front of one of our trail cameras!

A mouse climbs around on a tree branch. 

BIRDS

While our surveys are not designed to document bird activity- we still love when we get to see them! Our winter cameras captured some beautiful birds out in the woods but our favorite visit by far was this owl detection from early in the season! In it, an owl is seen on the ground, possibly eating something, and appears to be startled by a buck as they walk by! 

An owl looks up from the ground before flying away as a buck walks by. 

Another cool bird detection from early in the season was this pileated woodpecker. The pileated woodpecker is one of the largest woodpeckers found in Oregon. Although it is hard to make out in this photo- they can usually be identified by their striking red crests.

A woodpecker perched on a tree.

Birds in the Corvid family are common in the forests and in urban areas in our region! Of the Corvids, ravens are largest! The photo below was shared with us by one of our camera crew volunteers, who spotted this raven on the way to their camera site! We also had volunteers document raven tracks on a group tracking survey after witnessing the raven hopping around in the snow!

From top to bottom: A raven perched in a tree; Raven tracks documented on a tracking survey.

Another common Corvid is the Stellar's jay. 

A Stellar's jay standing in the snow.

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Gray jays, also known as Canada jays, are a common sight for birders on Mt.Hood! This gray jay was just barely caught within the frame of our camera before flying off! 

A gray jay perches briefly on a tree next to a trail camera.

That's it for our winter wildlife highlights! Thank's again to everyone who made this season so special! Be sure to check back next month for updates from our summer surveys!