Cascadia Wildlife Blog
News from the Wolverine Tracking Project and more
End of season newsSnow is melting on the mountain and we are stowing away our snowshoes after another successful winter survey season! Our last group tracking trip went out mid-March, and our camera crews will be heading out for their last camera checks over the coming weeks. This spring we will begin our transition from winter to summer surveys, with trainings for our Summer Camera Crew and Fox Scat Surveys starting in May! Spring is the season of renewal and new life! Many wildlife species give birth in the spring, including our community science projects namesake, the wolverine! Wolverines give birth in snowy dens between February and April. It's also the time when many plants start to spring forth from their earth, shoot out new leaves and begin to flower. What a beautiful time of year! This spring, Cascadia Wild is offering classes in tracking, botany and bird language! Come join us outside (and online) as we explore the natural world together! Upcoming Classes: April 16th, 8:00 AM- 2:00 PM: Bird Language Field Trip April 21st, 7:00-8:30 PM: Plant Identification (online) May 5th, 6:00-7:30 PM: Weed Walk May 7th, 9:00 AM- 4:00 PM: Sign Tracking Springtime plants!Here in the Pacific Northwest, springtime usually means rain, rain, rain! But with that rain comes our lush vegetation and gorgeous spring flowers! In the spirit of the season, we headed out to Hoyt Arboretum to document some of our favorite native plants that are springing to life! Hoyt Arboretum is a beautiful natural area in Forest Park (and accessible by bus!), with 12 miles of hiking trails and home to 2,300 species of trees and shrubs! The arboretum was established to conserve endangered species and educate the community- they have trees from all over the world! On our trip, we focused on plants that are native to Oregon- many of these plants are ones that you will find growing in natural areas around Portland, and even in some yards (especially those participating in the Backyard Habitat Certification Program)! If you are looking to dive deeper into learning about Oregon's native plants, join us for our online plant identification class on April 21st! Native Oregon PlantsIndian Plum (Oemleria cerasiformis), a common shrub in low elevation woodlands, is typically the first to flower in the spring! We missed their dainty white flower clusters this season, but Indian Plum is also easily identified by its broadly lance-shaped, pale green deciduous leaves. Fun fact: Indian Plums leaves smell like cucumber when crushed! Try it- you won't be disapointed! From left to right: A photo of Indian Plum showing the general shape of the plant: tall and tree-like; A close up of Indian Plum's leaves. Another common shrub in Oregon is Salmonberry (Rubus spectabillis), which often forms dense thickets along stream edges and in other moist forested sites from low to subalpine elevations. Salmonberry is easily recognized by its butterfly shaped leaves! Leaves form in groups of 3, as pictured below, and are sharply toothed. The two leaves opposite each other look like the wings of a butterfly. Salmonberry fruit looks a lot like a yellowish orange raspberry. These fruits will typically ripen between May-June, and are edible! Salmonberries are among the earliest berries to ripen in our region and were historically eaten by Indigenous communities along the northwest coast, often with salmon! Salmonberries don't appeal to all tastebuds, but for those who like them, they make a delicious trailside snack! From left to right: A close up of Salmonberry leaves; a bright pink Salmonberry flower. Salal (Gaultheria shallon) is abundant in the understory of coniferous forests and along rocky bluffs. Salal's evergreen, leathery leaves don't always stand out- but once you know it, you will see it everywhere! Salal is found in locations ranging from the ocean shore to medium elevation forested habitat. And once Salal begins to flower- you won't want to miss it! It has beautiful white or pinkish urn-shaped flowers that dangle in groups of 5-15 at the end of its branches. Its flowers are followed by dark-blue edible berries, which were an important fruit for many indigenous communities along the Northwest Coast. Salal growing in the understory at the arboretum. Oregon Grape (Mahonia spp.) is an iconic Pacific Northwest shrub! There are actually four species of Oregon Grape found in Oregon: Tall (Mahonia aquifolium), Dull (Mahonia nervosa), Creeping (Mahonia repens) and Dwarf Western (Mahonia pumila). Of these, Dull and Tall are most commonly found in areas around Portland, though Tall Oregon Grape is typically associated with drier environments while Dull Oregon Grape is more common in second-growth, closed-canopy conifer forests. That being said, we came across mostly Tall Oregon Grape on our trip at the arboretum- which can be distinguished based on it's height, the shininess of its leaves, the singular central vein of it's leaflets and the number of leaflets per leaf. All Oregon Grape species have distinct holly-shaped leaflets and bright yellow flowers (pictured below), which are replaced by small blue berries. From left to right: A close up of Oregon Grape flowers; Oregon Grape growing at the base of a Douglas Fir. Thimbleberry, or nature's toilet paper as some folks call it, is an abundant shrub found in open areas- along trails, roadsides, forest clearings and in open forests! The Thimbleberry we came across was just starting to get some leaves in- soon that cluster pictured below will be a dense thicket! Thimbleberry is affectionately referred to as nature's toilet paper due to its large, soft green leaves that can come in handy in a pinch! Soon we will begin to see Thimbleberry's delicate white flowers, followed by delicious red compound fruits mid summer. From left to right: A close up of a young thimbleberry leaf; a thicket of thimbleberry plants. The Pacific Northwest is home to a beautiful variety of ferns- many of which can be found in Forest Park year-round. One of the most abundant of the ferns is Sword Fern (Polystichum munitum), aptly named based on the shape of its leaves. Sword Fern is most often found in the understory of moist forested areas. Ferns, unlike many of the other plant species we've been looking at, reproduce via spores! Spores are dispersed via wind and often don't travel very far from the parent plant in closed forests. While spores are microscopic, you can often see the sori (groups of sporangia that contain spores) on the underside of the fern blade. From left to right: A Sword Fern plant; the underside of fern frond, showing its orangish sori. Another iconic Oregon native is Western Trillium (Trillium Ovatum)! These beautiful flowers bloom between February and June each year, but please don't pick them! Since Western Trillium grows in low light conditions, it can take between 7-9 years (or more!) for them to produce a flower. As Trillium plants get older, their flowers change from white to a pink or purple hue. So gorgeous, and definitely better left in the forest for everyone to enjoy! A cluster of Western Trillium surrounded by leaf litter. Vanilla-leaf (Achlys triphylla) is a perennial ground cover common in moist shady forests, along streambanks and forest edges. This simple, single stalk plant is easily recognized by its three fan-shaped leaves. When dried, the leaves produce a vanilla-like fragrance- hence the name! Vanilla-leaf growing alongside Sword Fern and other native understory plants. Duckfoot (Vancouveria hexandra) is another common groundcover in moist, shady forests. More often called as Northern Inside-out Flower, Duckfoot is a name that refers to the shape of its leaves! A cluster of Ducksfoot growing amongst Sword Fern and other understory plants. Non-Native PlantsThere are a lot of non-native plants at Hoyt Arboretum because it's a living museum of trees! The arboretum has tree and shrub species from all over the globe, including a beautiful trail of Magnolia species. While some Magnolias are native to the eastern United States, none native in Oregon. However, they are highly valued ornamental trees due to their beautiful and fragrant blossoms. Pink and white Magnolia flowers along the Hoyt Arboretum Magnolia Trail. Not all non-native species are invasive- Magnolias and other non-native trees at the arboretum are able to be safely planted because they are not likely to spread and out-compete native species. Invasive species are typically adaptable, habitat generalists with high reproductive outputs. Invasive species have negative effects on the ecosystem to which they are introduced- outcompeting other species for resources, disrupting food webs, or otherwise degrading the habitat. A good example of an invasive plant species that we see a lot of in Oregon is English Ivy (Hedera helix). English Ivy was introduced to the Americas by colonial settlers around the early 1800's as an ornamental garden plant. Now English Ivy can be found in forests throughout the Pacific Northwest, particularly in disturbed forested areas, where is displaces native ground cover and weakens or kills native trees. The dreaded English Ivy, creeping across the forest floor. That's all for our native (and invasive) plant expose! We are off to enjoy some sweet spring sunshine while it lasts, and hope you will too!
P.S. If you are looking for a good PNW plant identification book, we highly recommend Plants of the Pacific Northwest Coast by Jim Pojar and Andy MacKinnon! A lot of the information that we shared in this post was adapted from it!
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Upcoming classesWe are offering a lot of exciting classes this spring, covering a wide range of nature-based skills! If you are looking to brush up on your outdoor survival skills, check out our in-person fire building class on March 6th. Or come connect with fellow bird-lovers and learn more about the world of birds with our online bird-language class on March 10th. This class will be followed up with a field trip on April 16th so that you can practice your new skills! To learn about more of our upcoming spring classes, check out the classes page on our website! We have classes in botany, tracking, and a whole naturalist training program that runs from April through November! Wildlife FindingsThis winter survey season is flying by! We have lots of exciting findings to share with you from our camera and tracking surveys, including a few target species detections, a supersized feline, and much more! We are super grateful for all of our dedicated volunteers who have been working hard all season to help us collect this valuable data! Target SpeciesWe have had several target species detections (and potential detections) over the last few months! Back in January one of our high elevation un-baited cameras caught this glamour shot of a Sierra Nevada red fox out on a snowy day! There were a few other detections of Sierra Nevada red fox in this photoset, but only at night- we could just make out that white tail tip in the shadows. A black/silver morph Sierra Nevada red fox on a blustery day. Another one of our target species is the Pacific marten! We monitor these mini mustelids because they can serve as indicators of healthy upper elevation old growth conifer forests. Unsurprisingly, this marten was detected at one of our high elevation sites! We are keeping our fingers crossed for more detections of these furry friends throughout the rest of our winter survey season. A Pacific marten pauses while making their way through a camera site. Another one of our target species- the gray wolf- has been a little more illusive this winter. Gray wolves were extirpated from Oregon since the mid 1900s, due to predator control practices and declines in prey availability. Did you know that Cascadia Wild survey cameras provided some of the first documentation of their return to Oregon, back in 2018? Since their return, Cascadia Wild has continued to document their presence here with camera surveys and wolf scat surveys. While we haven't spotted any gray wolves on our cameras so far this winter, one of our camera crew volunteers did come across these large canine tracks! Large unknown canine tracks in the snow. These tracks are large enough that they could potentially have been left by a gray wolf, but they could also be from a really BIG dog! We are keeping our fingers crossed that this unknown canine friend stuck around and we can hopefully catch a glimpse of them on the camera! CarnivoresSpeaking of large carnivores, wolves aren't the only top predators in our forest! One of our volunteer's personal cameras recently picked up this strapping mountain lion, out on an evening prowl! A mountain lion strolling through the forest. Mountain lions (and gray wolves) are apex predators, meaning they are at the top of the food chain and don't have any natural predators. Healthy predator populations are important for maintaining prey species' population sizes which affects overall ecosystem health. In areas where predator populations decline, prey populations will often increase dramatically which can have negative effects on vegetation due to over-browsing. This phenomenon is referred to as a trophic cascade- where changes in populations at one trophic level (trophic levels are basically just the animals position in the food chain!) has direct and indirect impacts on populations at other trophic levels. The other member of the felidae family found in our region is the bobcat! Bobcat are significantly smaller than mountain lions, and easily identified by their mottled coat and short tail. Canada Lynx, which also have a smaller body size and short tail, have a more northern distribution and are not found in Oregon. A bobcat investigates a camera site baited with deer meat, and walks away satisfied. In the bottom two photos, a bobcat is seen showing off their expert climbing skills in an attempt to get at the deer leg our volunteers had strapped to this tree! We switched away from using meat to bait camera sites a few years ago in favor of hormonal and scent based baits. However, we are baiting two camera sites with both hormonal lures and deer meat as part of a regional survey for wolverines being coordinated by the ODFW. For better or worse, when this bobcat was done with their two night deer meat feast, there was nothing left for any possible wolverine visitors! Unlike bobcats and mountain lions, who are obligate carnivores (meaning they only eat meat) the next two predators are actually omnivores! Black bears, who we don't often see out frolicking in the snow like the bear below, have a broad diet that depends on both their location and the season. They eat berries, fruit, sedges, grasses and insects, and will hunt deer fawns in the spring. They are also known to claim deer and elk carcasses depredated by mountain lions. A black bear rolling and rubbing against a bait box semi-buried in snow. Coyotes are also omnivorous and highly adaptable. They will eat berries, mushrooms, insects, small mammals and fawns- depending on what they can get their paws on! From top to bottom: A coyote passes through a snow dusted, lower elevation camera site; two photos of inquisitive coyotes checking out the bait at our camera sites. A coyotes diet can dramatically impact the way their scat looks like! The scat in the photo below is most likely coyote scat, based on the size, twisted appearance and tapered end. It is a little hard to tell because the scat is so frozen, but if you look closely you can see some hair in there! Probable coyote scat found near a camera survey site. We haven't had very many skunk detections these past couple months but one camera did capture this skunk hurrying through the snow. Skunks are typically less active during the winter, as food supplies are scarcer they tend stay in their burrows- check out our previous blog post about hibernation and torpor to learn more about what they are doing to conserve energy during this time! Skunks are primarily insectivorous, but will also eat small mammals, fruit and bird eggs! A striped skunk scampers through the snow. Another miniature mustelid found in Oregon, and our smallest mammalian predator, is the weasel! A weasel scurries around the trunk of a tree. There are two species of weasels in Oregon, the short-tailed and long-tailed weasel, which are practically indistinguishable in the field. Weasels prey is dependent on their size- short tailed weasels focus on mouse-sized prey, while long-tailed weasels prey primarily on ground squirrels and mountain beavers. UngulatesWe have a good amount of deer detections over the last month- almost all of them at lower elevation sites and sites in our East forest survey region. This is pretty typical of deer distribution on Mount Hood in the winter months- there is more to eat at lower elevations and deer follow the food! From top to bottom, left to write: Two deer browsing on vegetation; A deer stares straight at our trail camera; Another deer, this one with a bit of vegetation hanging from their mouth, looks right at the trail camera. There was a single elk detection at one of our cameras over the last month, also at a lower elevation survey site! The volunteer checking this camera actually spotted a small herd of 8-12 elk (including two males) on their way to the site! The elk didn't stick around long, but they did leave behind lots of tracks and scat (shown below). From top to bottom, left to right: An elk passes by, partially obscured by the trees; An elk track in the snow; Lots of elk tracks and scat in the snow near a camera site. Small MammalsOur cameras aren't set up to attract small mammals but that doesn't mean we aren't happy to see them when they stop by! Healthy prey species populations support healthy predator populations! We have had several snowshoe hare detections at camera sites, and many more on tracking surveys! A snowshoe hare hops through the snow. Squirrels are a frequent visitor at camera sites and their tracks are also commonly found on tracking surveys. This time of year we mostly expect to see Western gray squirrels, Douglas squirrels and the occasional Northern flying squirrel. From top to bottom, left to right: A Western gray squirrel digging in the snow at the base of a tree; A Douglas squirrel pauses in the middle of a camera site; A Northern flying squirrel climbing on a bait box. From left to right: Probably squirrel sign- nibbles on a lodgepole pine twig, marks left at a 45 degree angle; The cone remnants of a squirrel feast. Thanks for tuning in to our blog this month and be sure to check back next month for more cool wildlife findings and updates on our upcoming summer survey season!
Hibernation and Torpor explained!There's no denying that winter can be rough- even for us! Colder temperatures, limited daylight and less food availability combine to make winter a challenging season for many of our animal friends. There are a lot of different strategies that have evolved for overcoming these winter woes! The PNW has a temperate climate, which means we have relatively mild winters but temperatures can still get pretty cold, especially on the mountain! Food is generally more scarce in the winter in this region and less daylight hours means less time spent foraging for most animals. Animals evolved different strategies for dealing with winter based on a few different factors, notably, thermoregulation strategies and body size. Endothermic animals are animals that maintain their own internal body heat, as opposed to exothermic animals which rely on external conditions to regulate their body temperature. These two thermoregulation strategies are often colloquially referred to as warm-blooded and cold-blooded. Endothermic animals (mammals, birds and some fish!), have higher energy needs than do exothermic animals because of the energy demands of maintaining their body temperature. In the winter, when temperatures drop and food can be scarce, some endotherms are not able to obtain the amount of energy needed to maintain their internal body temperature and will use hibernation or torpor to conserve energy. Exotherms may also enter a period of reduced physiological activity, called brumation, at cold temperatures. Similar to hibernation, during brumation an exotherm's body temperature, heart rate, respiratory rate are significantly lowered. Body size is also a factor in determining how an animal deals with winter weather. An animal's surface area to volume ratio determines how fast they lose heat; really small animals (like a squirrel or a hummingbird) have high surface area to volume ratios, which means they lose heat more rapidly than a larger animal (say a deer or bear) would. This means that smaller animals end up using more energy to maintain their body heat than larger animals that are able to retain more of their body heat. Which explains why lots of small mammals in cold climates resort to hibernation or periods of torpor during the winter! How much body fat an animal is able to hold will also play a role in determining an animals winter survival plan! Animals that are able to hold a lot of fat on their body (like marmots) are able to hibernate for much longer than animals with limited fat stores. In this post we are going to discuss who is hibernating right now in the PNW, explore the difference between hibernation and torpor, and try to unpack what the *heck* bears are doing in those dens all winter long! Whose hibernating?Some endothermic animals hibernate over winter in response to cold temperatures and a lack of available food. Hibernation allows animals to conserve energy by lowering their body temperatures and metabolism. During this period, animals breath rate and heart rate slow down and they appear to be in a deep sleep. True hibernators are the animals that are unable to be woken up during this period, regardless of outside stimulus. True hibernators in the Pacific Northwest include yellow-bellied marmots, ground squirrels, bees, and some bats! A yellow-bellied marmot soaking up some summer sun. Marmots are extreme hibernators- they spend over half the year in hibernation! In Eastern Oregon, yellow-bellied marmots enter hibernation towards the end of July and emerge from hibernation in late February/ early March. If July seems a little early for a hibernation to begin, keep in mind that in this region, all the plants die back midsummer, so a lack of food availability spurs their early retreat! Those little bodies actually store a lot of fat, which is how they are able to hibernate for such long periods! A golden-mantled ground squirrel running across a rocky landscape. Golden-mantled ground squirrels are active from early spring to mid August, after which they hibernate for a period of 5-8 months. Unlike marmots, who subsist off of stored body fat, these ground squirrels have brief periods of activity during their long winter hibernation during which they will gorge on cached seeds. A California ground squirrel caught in action! California ground squirrels are facultative hibernators, meaning that they will hibernate if they experience cold or food stress but in warmer parts of their ranges are active year-round. A bat darting through the night. There are 15 bat species in Oregon! Some of these species migrate to escape the colder winter months, while others, such as the little brown myotis, hibernate in caves through the winter. What's Torpor?Torpor is another physiological mechanism for conserving energy which similarly involves a reduced body temperature and metabolic rate. The main differences between torpor and hibernation is that torpor is short term (hours, days or weeks), compared to months of hibernation, and animals can be easily roused from torpor, which is not the case for hibernating animals. Animals that utilize torpor to help survive the winter months in the PNW include hummingbirds, chipmunks, skunks, badgers, deer mice! Hummingbirds often enter a state of torpor nightly, especially in colder climates. Since their surface area to volume ratio is so high, hummingbirds lose heat quickly and must eat almost constantly throughout the day to keep up with the demands of maintaining their body temperature, as well as the energy demands of flight. At night they enter a torpid state, lowering their body temperature, metabolism, heartbeat and respiration rate to conserve energy. A striped skunk sniffing around! Skunks will go into torpor when temperatures are particularly low, and food supplies are scarce, as a way to conserve energy. Since they are nocturnal, they go into torpor during the day! An American badger moseying around in the woods. Similarly, badgers will go into a state of torpor if temperatures are low. They are rarely seen above ground when temperatures are below freezing- preferring to stay in their dens in this dormant state. A chipmunk perfectly perched in view of the trail camera. Chipmunks typically spend the winter snuggled up in their burrows in a state of prolonged torpor- rising occasionally to snack on food they cached in the fall. A little mouse making their way across a fallen branch. Deer mice utilize a variety of strategies to keep their tiny bodies warm in the winter: huddling, nesting, and torpor. While huddling together or building a deep nest is likely enough for most deer mice to withstand Oregon's winter temperatures, if temperatures become too cold then they will resort to torpor. So, What are Bears doing?There has been a lot of debate over the years as to what the *heck* bears are doing all winter long! Many scientists have argued that bears are not true hibernators because their body temperatures do not lower to the same extremes as other true hibernators (marmots, ground squirrels) do. This means that they are more responsive during the denning period than a true hibernator would be. Some scientists now distinguish what bears do as super hibernation, because they do not eat, drink, defecate or urinate during the hibernation period. Other people take issue with that classification and believe that bears are actually in a long-term torpid state because they remain semi-alert and responsive throughout the season. A bear taking a break! Many black bears in Oregon don't retreat to their dens for periods of dormancy, anyways! Our temperate climate means that bears at lower elevations can find enough food throughout the winter to remain active.
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