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Sunday, February 26, 2017

Mammal Course - Class #2 Canids and Ursids

Our 2017 "Conservation Course" started February 6th.  Below are notes taken by Avery Young.  See notes and videos from the previous classes here:
Class #1
Learn more about the Mammal Course here

Class #2 - Canids with Scott Fitkin and Ursids with Dr. Bill Gaines, Feb 13 2017

Watch and listen to the entire class on this video

Before Scott started, he shared a list of the Carnivores of the North Cascades (*indicates threatened or endangered species)
Black Bear
*Grizzly Bear
*Gray Wolf
Cascade red fox (this is the native fox that we could see in the Methow or Cascades)
European red fox (this is the introduced, non-native fox that is relatively common both east and west of the Cascades)
*Canadia Lynx

The North Cascades and surrounding area are full of Canids. Canids are a line of carnivores that includes wolves, foxes, coyotes, jackals and domestic dogs. Canids typically have long muzzles for smell and larger ears for hearing. They are vocal, and quite leggy, as they do a lot of traveling.

There is a morphological gradient across members of the Canid family that makes it easy to identify a fox from a wolf. For example, wolves are the largest (60-120lbs), foxes the smallest (8-10 lbs) and the coyote is somewhere in between (25-40lbs). Large ears are most prominent on a fox, and least prominent on a wolf. Wolves have the longest legs and foxes have the shortest.  Wolves are also the most social and foxes the least social.

It is a little trickier to identify a wolf from a coyote, but the best diagnostic is to look at size (wolves are noticeably bigger with a more robust head). Wolves also have a prominent black patch on their nose. It can get pretty complicated if you come across a juvenile wolf in mid-summer and fall, as they can closely resemble a mature coyote. You do not have to worry about coming across a coy-wolf (coyote-wolf hybrid) on the west coast as coy-wolfs only exist east of the Mississippi river.

If you’re looking at tracks, the feet of all canines look similar but size (full grown wolf tracks are distinctly larger than coyote tracks), and a few specific characteristics can help distinguish them all.  The “X” test is what you can use to identify a canid from a cat. On a canid you should be able to drawn an “X” between the pad of the foot and the two front toes - the space not taken up by the toes and the pad creates “negative space” that can look like an “X.”  On cat tracks, you have to weave between toes and pads - the “line” is more round and not in the shape of an X. Another test to distinguish between canids and cats is to looks at the symmetry of the track; canids have symmetrical tracks with the two front toes side by side; cats are more asymmetrical and one toe leads the others (similar to our hands with one finger slightly higher than others.

Wolves are a keystone species - they play an extremely important role in the maintenance of a healthy eco-system. The reintroduction of wolves to Yellowstone National Park back in the 80’s quickly controlled the elk population, which allowed more trees to grow, which brought beavers who created wetlands and wetlands that brought fish and song birds back to Yellowstone. Wolves were once very common in Washington. But between 1827-1859, 14,810 wolf pelts were traded at four WA posts. Wolves were nearly wiped out of this part of the world.

A member of WA's Lookout Pack on remote camera by David Moskowitz
Wolf management really comes down to people management.  There are currently two, possibly three, active wolf packs in the North Cascades: the Loup Loup pack, east of Methow River between south of Twisp to north of Winthrop in general; the Lookout Mountain pack, west of the Methow River between Twisp and Winthrop in general; and a possible pack forming in the northwest section of the Valley west of Winthrop up to Mazama. The wolves, whose territories can be between 50 and several hundred miles, operate largely on our deer-rich economy. Can you imagine what the deer population might be like if we didn’t have wolves here?  Despite four illegal poachings in 2008, these wolf packs have remained relatively resilient and their presence helps the Methow Valley maintain a healthy ecosystem.

Methow coyote by Mary Kiesau
Coyotes are the “heartiest” of the Canids and are found in a wide variety of habitats.  Coyotes can often be seen hunting in fields, pouncing in the air to hop down on mice and voles. They also eat hares and rabbits, squirrels, and even birds like geese, and will occasionally go after an injured adult deer or seasonal young fawn. Their territory is ½ mile to 25 miles depending on how rich an area is with prey.

Fox in the Yukon by Mary Kiesau
The cascade red fox is a cold adapted, high altitude specialist. The European red fox was introduced here in the 1800’s as their pelts were highly valued back home. There is no evidence of interbreeding between these two species.  The European fox can be found both west and east of the Cascades but not in the Methow or Cascades.  Foxes eat small rodents, voles and other microtines. They will occasionally eat berries and small birds. The Cascade red fox is likely to decline with climate change because it is adapted for colder environments. These animals are difficult to track and spot in the wild.  The Cascade red fox can have a variety of coat colors from deep red to tan to black.  It  can  always  be  distinguished  from other canines by its white-tipped tail.  There is still much scientists do not know about foxes.

Black bears has been in North America a long time. Grizzlies are more recent. The grizzly and polar bear are closely related and there is some interbreeding where the two species co-exist. Grizzly and black bears do not interbreed.

How do you tell a grizzly bear from a black bear? Claws, shape of head, and shoulder hump are the three characteristics biologists use to distinguish the two bears (along with DNA analysis for hair). A grizzly has a large, broad face and small, round ears compared to the rest of the body.  Black bears have a longer nose and taller ears, in relation to their head. Grizzlies have a hump where their back meets their neck. Their hump is a shoulder muscle that helps them to dig. Black bear claws are more hooked so they can climb trees better. Grizzlies’ are straighter and much longer for digging.  Because of this claw marks on grizzly tracks are much further away from the toes than on black bear tracks.  Both bears have 5 toes but you should be able to draw a straight line underneath the toes of a Grizzly; not so on a Black bear where the lowest toe will far under this imaginary line. A good saying to remember is, “If the toe is back, the bear is black.”

Color isn’t a good indicator to identify these bears because 70% of black bears are blonde, strawberry blonde, brownish or something other than black, and all grizzly bears are brown bears, but not all brown bears are grizzly bears. On the western side of the Cascades, more of the black bears are actually black. Black bears on the East side of the Cascades have adapted to being more blonde because we have more sage brush while the west side has more deep dark forests which helps the black bears blend in really well.

Bears live up to 30 years in wild. Males are solitary most of time. Males and females will court each other for up to 1 month before breeding.  Black bears females are around 3 or 4 years old when they first mate. Grizzlies are 5-6 years old. Delayed implantation occurs in bears when they mate in the spring. The fetus develops to a certain point and if food sources are good, it will continue, if not, the female’s body will abort it.  Females go into “hibernation” (they aren’t true hibernators, see below), and have cubs in the middle of winter in dens.  Survival of cubs depends on food resources: they have a 50/50 chance. The greatest cause of bear mortality is humans via hunting, poaching and vehicles.

Black Bear in the North Cascades Nat'l Park by Mary Kiesau
Neither species go into true hibernation but their heart rate slows considerably from 40-50 beats per minute down to 8-10 bpm.  This form of deep sleep is called torpor.  Their bodies consume their fat and their muscle remains. They don’t urinate or defecate during hibernation.  Scientists are interested in studying their tolerance to cholesterol and toxins that build up in their kidneys and liver.  Bears can dig dens, get inside hollow logs, go under thick brush and fallen logs, and some just dig a scrape on the ground and let the snow cover them.  Bears can come out of “hibernation” if the temps are well above normal, if they are disturbed or if they get very hungry.  In certain warmer areas, bears do not hibernate at all. 

Grizzly Bear in the Yukon by Mary Kiesau
Researchers have been working for years to understand the vital role bears play in ecosystems. Bears are an umbrella species- a Grizzy male covers 300 square miles and a female covers 100 square miles. They tend to space themselves out. Bears digging in Yellowstone help maintain meadows, because this rototiller action prevents conifers from growing.  Both species can eat hundreds of pounds of salmon or other fish in coastal or riverine environments, leaving carcasses for numerous bird and mammal species to finish, and helping spread the rich fish nutrients around the land.

The federal government used to hire men to kill bears in North America. During 1830-1860 about 4,000 grizzly hides were processed from the North Cascades.  The last legally hunted grizzly bear was shot in 1967 in what is now the North Cascades National Park Complex.  Glacier National Park currently has the largest population in all of North America.  The opportunity to recover grizzly bears here in the Cascades via the Grizzly Bear reintroduction proposal by the National Park Service is unique. Grizzlies need a huge territory to repopulate themselves, and not many territories exist like this in North America or even the world. Grizzlies are the second slowest reproducing mammal right behind the musk ox. They are likely to go extinct unless we intervene. The black bear population is currently very robust.  If grizzlies get reintroduced, it will be a few bear per year over 20 years or so, and they will likely fill high elevation niches and send the Black bears down to the forest where their evolution took place.  It will still be very unlikely that we humans would ever see a grizzly in the North Cascades.

Bear attacks do happen, but they are rare. Bear attacks are tragic but the greatest risk of hiking in bear country occurs when you are driving to the trail head as the risk of having a fatal car accident is much higher than the risk of ever even seeing a bear in the wild.  The potential for having an adverse encounter with a grizzly bear is extremely low even in grizzly country like Alaska.  Even when they occur, most bear encounters do not lead to human injury.  The number people killed by cougars is the same as grizzlies.  Adverse encounters can usually be avoided through awareness of conditions that may cause an encounter. Keeping a clean camp, not approaching wildlife too closely, and avoiding situations that might unknowingly surprise a bear will greatly decrease the risk of having an unwanted bear encounter, or causing someone else to have one. Proper sanitation practices (in camp and with garbage receptacles), carrying and learning to use bear spray, and familiarity with bear behavior are likely to be the best safeguards against unwanted encounters.

See loads of details at the Grizzly Bear Outreach Project
Learn about the proposed North Cascades Grizzly Reintroduction Plan, including how to comment here.

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