Cascadia Wildlife Blog
News from the Wolverine Tracking Project and more
|
Winter is in full-swing, January brought us deep snows and lots of photos from the Wolverine Tracking Project, and looking ahead, February is shaping up to be a busy month with March not far behind! See below for news on our camera and tracking surveys. But first, check out some of the classes and events on the calendar. Upcoming classes & events
As always, Tracking Club meets the last Sunday of every month. Nature Book Club meets Feb 25 to discuss Reading the Forested Landscape by Tom Wessels. More info on Clubs Camera SurveysA big thank you to our volunteers who have been braving the elements to maintain our camera sites! All the fresh snows on Mt Hood have given our camera crews a lot of opportunity for snowshoeing, digging cameras out of the snow, and bringing back some great photos! We've captured a few winter photos like this (below):  A snow-covered camera takes a programmed, daily photo However, thanks to our volunteers braving the elements, we have also detected a lot of wildlife. When the heavy snows weren't burying our cameras, which were originally installed about five and a half feet up a tree, they were making some cameras appear to be at ground level. The result? These wonderful close-ups: 
A Pacific marten inspects a camera, leaving behind footprints in the freshly fallen snow It is always exciting to see a Pacific marten, especially so intimately. We love that we can also see such clear tracks as it departs, too. Note the elongated foot pad of its back feet, circled by five toes. This print is characteristic of mustelids, the family which Pacific marten, wolverine, fisher, mink, weasel, and so on belong. A little about marten...
Snow-level cameras also detected some other animals, which make up our marten's carnivorous diet:
A deer mouse leaves a trail (left/top) and a snowshoe hare comes for a visit (right/bottom). The fresh tracks of the deer mouse show it's hopping gait - though much smaller, it is very similar to the trail a snowshoe hare would leave: small front feet landing first and the larger, more powerful hind feet landing second just ahead of the front feet. We also detected an up-close and candid portrait of another target species: the Sierra Nevada red fox!  A Sierra Nevada red fox makes its way through deep snow Again, you can see the tracks of this montane fox in the snow. With a meandering trail like this and nose to the ground, it's not hard to assume this fox is hunting. Rodents often burrow into the snow, using the insulating layer as protection from predators and the cold.
Foxes at three different sites inspect the bait trees (top row and bottom left). A video shows multiple visits of what appears to the be the same fox to one site over a period of three weeks (bottom right). These many visits from these rare, native foxes help us understand their habitat use. We have also collected a few viable hair samples from some of these sites. Like scat samples, hair samples may help give us important genetic information to help us understand their population history, genetic diversity, and habitat connectivity. Hair samples are collected on wire brushes, which are attached to the black belt on the tree just under the bait. Our region is home to three kinds of montane fox, the Sierra Nevada red fox (Vulpes vulpes necator) in the Oregon Cascades and Sierras, the Cascade red fox (V.v. cascadensis) found in the Cascades north of the Columbia River, and the Rocky Mountain red fox (V.v. macroura) who are native to northeast Oregon. And, just this week, it was announced that there is a population of Rocky Mountain red fox living near Bend, and likely has been in this area for some time! Just like the Sierra Nevada red fox in our backyard, the montane fox can be elusive and difficult to study, even when they are right under our nose. Other recent visitors include the ever-present coyote.
Left to right (mobile: top to bottom): a coyote fixates on a tree; two coyotes look on while a third rolls in fresh snow; a coyote with a white-tipped tail pauses, then leaps over a log to smell a stump; and finally, a coyote stands chest-deep in the snow, likely listening for rodents. Though the final coyote's retreat was not captured, its tracks show it departed the way it came, taking the time to circle (and likely mark) the stump behind it (final photo). We've also detected a few bobcat:
Left to right (mobile: top to bottom): a bobcat walks past a bait tree; bobcat walks down a game trail; bobcat inspects a bait tree; bobcat leaves tracks in fresh snow; bobcat smells the base of a bait tree; and a bobcat passes through a site with what looks like a freshly caught hare The bobcat on the right (or bottom), is difficult to make out. However, this lucky visitor is sporting a freshly caught hare! Bobcats (Lynx rufus) are well-adapted for snowy mountains, and, like foxes, marten, and coyotes, snowshoe hare are a favorite snack. Bobcats often hunt at night, and like the marten, don't let their small size fool you! They can cover 10 feet of ground in one pounce. We are more likely to see bobcats on the mountain in the winter than their felid cousin, mountain lion. Mountain lions (Puma concolor) are less adapted to snowy environments than bobcat and are more often detected at lower elevations than where most of our cameras are located. Another visitor we don't expect to see in the winter? Black bear. However, our cameras did pick up a bear between snows, a bit later than we would expect to see one.  A black bear walks down a game trail between winter snows Bears do not hibernate in the same way as most other animals, like some rodents and reptiles, who lower their body temperature along with their metabolism and sleep throughout the whole winter. Instead, they enter a state called torpor where their metabolism slows down, but their body temperature remains elevated and they are able to wake more easily. They can wake from this sleep-state during winter if the weather warms or they are disturbed, and they may even leave their dens, eating opportunistically if they come across food, but do not tend to venture out for long. Other animals that enter a similar torpor state are raccoons and skunks - plenty of reasons why it is always good to be aware of your surroundings in the forest! Whether this particular bear is taking a mid-torpor stroll or has yet to enter this state for the winter is hard to say. One animal, we are not surprised (but always happy) to see is the black-tailed deer.
Left to right (mobile: top to bottom): A doe in the snow; a buck in the snow; three deer in the snow; a buck on a game trail Did you know Oregon is home to four native subspecies of deer? Mt Hood National Forest is home to the Columbian black-tailed deer (Odocoileus hemionus columbianus), a subspecies of mule deer. These deer are found from the coastal ranges to the Cascades, and their range runs from California to northern British Columbia (a sister subspecies, Sitka black-tailed deer, is found in Alaska). Rocky Mountain mule deer (O.h. hemionus), another mule deer subspecies, are also native to Oregon, and they are found on the east side of the Cascades summits, most commonly on the east side of our state - fittingly, their range also includes both the American and Canadian Rockies. Black-tailed deer are a little smaller and darker than mule deer, but both have large, mule-like ears. While mule deer seem to prefer open steppe, black-tailed deer tend to prefer brushy areas of coniferous and mixed-coniferous forests, sticking close to clear cuts and burns for browsing opportunities. Oregon is also home to two subspecies of white-tailed deer: the Columbian white-tailed deer (Odocoileus virginianus leucurus) and the Northwest (Idaho) white-tailed deer (O.v. ochrourus). The Columbian white-tailed deer is the most rare deer in Oregon. They only live along the lower Columbia River and Umpqua Basin, and the Columbia River population is a federally protected endangered species. The Northwest white-tailed deer is found in the northeastern corner of our state and has a healthy population. As a species, white-tailed deer grow increasingly more abundant as you move toward the east coast. They can be found from Canada to South America and prefer mixed-deciduous forest types. In our area, you are most likely to see Columbian black-tailed deer - or if you are lucky, the rare Columbian white-tailed deer. Columbian white-tails have long tails they keep held closely to their bodies, and black-tails have shorter tails held loosely to their bodies. If you head a bit further east, you may see the Northwest white-tails; these are the smallest deer of all and have very wide tails. The antlers of each species are different, too. If the antlers are fully developed, white-tailed deer have one main beam on each antler, with points coming of the main beam; black-tailed deer (and mule deer) will typically have a fork coming off the main beam, with points coming off each branch. Check out ODFW's site to read more about our native deer or watch a video on Columbian black- and white-tailed deer identification. Almost as copious as deer and as perennial as coyote, are our forest corvids.
Left to right (mobile: top to bottom): Clark's nutcracker; Canada jay; and a video compilation of the two species visiting the same tree over two weeks - almost every 1-2 frames is a new visit. Tracking surveysPlentiful snows, hearty trackers, and some luck have resulted in some great tracking surveys! One tracking team encountered three separate bobcat trails:
Detail of bobcat tracks; another bobcat's trail The track quality on these tracks is great, even with a dusting of snow falling after they were laid. These photos show nice clarity of both the individual tracks and the trail pattern, and you can easily see the characteristic felid shape in these tracks. Compared to canid tracks, the whole of the print is quite circular and the thick, oblong pad is surrounded by four evenly spaced "toe beans." When distinguishing between dog and cat tracks, it's better to pay attention to these characteristics, rather than the presence or lack of claws: while felid claws are retractable (and canids are not), a bobcat or mountain lion can extend its claws for traction - something you may see on, say, a snowy/muddy/icy mountainside. Distinguishing bobcat from mountain lion is easy, at least for the adults of the two species: go by size! Under 2.25" diameter is likely bobcat; greater than 2.75" is likely mountain lion. The two tracks we are seeing the most of are snowshoe hare...
Left to right (mobile: top to bottom): the meandering path of a snowshoe hare; older tracks show the commonly seen track pattern of undefined, large hind feet ahead of the small front feet; a tracking team examines a snowshoe hare trail along a log; detail of exceptionally clear hare tracks. ...and squirrel:
Similar to the snowshoe hare, the older squirrel tracks show the commonly seen track pattern of undefined, large hind feet ahead of the small front feet; detail of clear squirrel tracks. The abundance of hare and squirrel is great news for the bobcat, whose tracks were found above, and the rest of our forest carnivores. The photos above show how similar these two animal's tracks are, both animals having bodies well-suited for bounding along, close to the ground. They can be difficult to discern from one another, but hare will be larger than a squirrel, and hare's tracks often have less definition due to the impressive amount of fur covering their pads and toes. Squirrel tracks are also more uniform and boxy - note how well the feet line up on the bottom set of squirrel photos, compared to the more staggered landing of the hare's front feet. In our forest, we have two kinds of non-hibernating squirrels: the Northern flying squirrel and the Douglas squirrel. However, it is difficult to tell their tracks apart. One way to tell? If you can follow the trail to the start, there will be a "landing strip" where the flying squirrel hit the ground. If you have clear enough tracks, you may be able to tell that the 5th toe on the hind foot (the "pinky toe") is almost as long as any other toe - that's a flying squirrel, too. Read more squirrel track analysis by David Moskowitz. Whether in town or on the mountain, we hope to see you soon!
0 Comments
|
