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Occasional posts - from the quirky to the momentous - on the life and times of the Methow Conservancy.
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Monday, March 13, 2017

Methow Mammal Course - Class #4 Felids & Mustelids

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
Class #2
Class #3
Learn more about the Mammal Course here

Class #4 - Felids & Mustelids with John Rohrer, Feb 27 2017
(our video of the class is giving us difficulties - we'll load it as soon as we can)

The native cats of the Methow are:
Lynx canadensis - Canada Lynx
Lynx rulus - Bobcat
Puma concolor - Cougar

Cats, or Felids are the perfect predator.  Their long, sharp, and circular canines are made for puncturing and grabbing prey. Felids have a short face, which makes for a powerful bite.  All of their canine molars are made for sheering meat. Felids orient their life visually and aurally. They use their eyes and ears to navigate life. They have 270 degrees of peripheral vision. Their external ears are designed for funneling sound down to their ear drums. Cats have 32 muscles on per ear, and they can move each independently.  Their flexible spine allows them to stretch out when they run. Speed and power are distinguishing characteristics of a Felid’s hunting prowess.

Mountain lion common names include: cougar, puma, panther, catamount depending on where you are.  The cougar is considered the most successful mammal (meaning they have the largest range) of the Western hemisphere going from north of Canada clear into Patagonia. Cougars are extremely territorial, and their territories can be 50-150 sq miles (males have much larger territories than females). In 1996, hound hunting became outlawed in WA, which inadvertently led to six cougar projects in the Okanogan. Biologists found that the adult males control the territories of all the cougars in an area, and that removing these adult males upset the social structure. The niche would get filled by 2-3 younger cougars who hadn’t “learned the ropes” yet which led to an increase in human conflict. On average around 50 cougars are killed via hunting in Okanogan county per year, and the remaining population is considered numerous, healthy and stable. Cougars can generally be found up on rock crops or other perches where they can see landscapes and potential prey well.  They are actually *not* typically found in trees.  They can climb trees, and will if they feel threatened by dogs, but generally, cougars are not hanging out high up in trees. 

Some additional resources include:
The Mountain Lion Foundation
WDFW’s Living with Cougars webpage

Bobcat from a remote camera by David Moskowitz
Bobcats are habitat and prey generalists. They exist in every state except Alaska, HI and Delaware, and can thrive in numerous different habitats. These cats lead solitary lives and feed almost exclusively on rodents. They have small feet, proportional to their body, and are not adapted for deep snow. Bobcats exhibit sexual dimorphism; females get up to 15lbs while males can be 20lbs or more.  Bobcats are common in the Methow Valley but they hunt at night so we rarely see them. 

Lynx are habitat and prey specialists. They eat almost exclusively snowshoe hare and prefer higher elevation forests with deep winter snow. They have long legs and huge feet (like snowshoes) which allow them to move efficiently. In the fall, they grow hair on the bottom of their feet. The snowshoe hare and lynx are textbook examples of the predator/prey cycle. It is hare abundance that drives lynx population dynamics from survival rates to den site selection.

Bobcats and lynx look similar and are often confused, though they are often separated by habitat, as mentioned above.  They both have “bobbed” tails but lynx have an entirely black tail tip, while the tip of a bobcat’s tail is black on the outside, and white underneath.  Lynx have much longer ear tufts than bobcat, and they have a larger/fuller face ruff.  Then, of course, there’s the feet: lynx are 4.5 inches across and bobcat are at most 2.5inches.  In a track, lynx have indistinct toe pads because of their furry feet, but cougar or bobcat have very distinct toes in the track.

In Washington, the trapping season for lynx was closed in 1993 when the animal was listed in the state as threatened.  The lynx was listed Federally as threatened in 2000.  After a 2016 status review by WDFW, the Washington Fish and Wildlife Commission uplisted the animal from threatened to endangered in WA in December 2016 (see the most recent WA State review here). 

Furs were highly sought after in the 20th century. 98% of lynx are distributed in Canada, while the remaining 2% reside in the lower 48 in 6 unique spots. Northern Maine has the most with 500-600. Most of their habitat in Maine is private lumber areas. NE Minnesota has from 15-200. They are also found in Montana and Wyoming. Yellowtone has not had a lynx since 2010.  We have lynx here in North Central Washington with the best estimate currently around 40-55 individuals.

Fires greatly affect lynx population.  Here, the north side of Lake Chelan to upper Twisp River is their territory.  Since so many fires have affected the same habitat zone as the lynx, it’s important to note that since 1994, fires have reduced over 30% of lynx habitat. Lynx cannot live in fire-ravaged areas, so they are sometimes forced to go into other lynx territories.

Why did the fire push them out?  Typically, wildfires destroy about 10-15% of lynx habitat. However, in the last 10 years, fires have gotten much more intense and now 30-40% of lynx habitat is destroyed by our fires. The amount of time it will take for these habitats to recover, and be able to provide a living place for lynx, is 15-20 years.

Why do fires affect lynx habitat so much? The answer lies in the snowshoe hare/lynx relationship.  Snowshoe hares need ground level coverage as well as ground level conifers for nutrition. The fires make it very hard for hares to survive. If there are few hares, the lynx will also be scarce.  As climate change continues to reduce snowpack and/or create earlier spring run-off, we can expect to see a reduction in the hare population. Furthermore, the mid-winter thaw/freeze cycles allow the snow to harden and other predators can go to lynx habitat and compete with them.

Q: Rumors say there has been a lynx in Winthrop recently, is that true?
A: Probably not because of the lower elevation. If you ever think that you might have seen a lynx, go get a track. The so called lynx in Winthrop was likely a bobcat.

The Methow members of the Mustelidae Family are: 
Short tailed weasel
Long tailed weasel
River otter
(skunks were recently moved to a different family)

Mustelids are the largest and most diverse family of carnivores.  They can be arboreal, aquatic, fossorial (under ground), subnivean (below snow), or chionophillic (snow lover). All Mustelids have musk glands in their anal glands.  They are typically small animals with short legs, short, round ears, and thick fur. Most mustelids are solitary, nocturnal animals, and are active year-round.  Most female mustelids have delayed implantation: the embryo does not immediately implant in the uterus, but remains dormant for some time.  The normal gestation period can be extended up to a year. This allows the young to be born under more favorable environmental conditions.

Badgers: 20 years ago, they were uncommon but are beginning to become more common.

River otters (Lontra canadensis)
Methow river otters by Mary Kiesau
are adapted for water and have webbing between their toes. Their nose and ears close completely to keep water out, and they can hold their breath for 3-4 minutes.  They have thick, lush hair that prevents water from reaching their skin.  They are relatively common in certain areas of the Methow, especially large ponds.  Otters are an indicator of healthy streams, rivers, and water bodies.

Why have badgers and river otters increased as of late? River otters were still being trapped up through the 90’s. Badgers are more mysterious, but it could be because of a warming climate and also, better awareness; badgers don’t get shot as varmint as much as they used to.

Fishers (Martes pennanti) were considered extirpated from WA by the mid-1900s due to population and habitat loss from logging, trapping and poisoning.  In 1998, the Washington Fish and Wildlife Commission listed the fisher as endangered in the state.  The Dept. of Wildlife is now actively reintroducing fishers in the Olympics, Southern Cascades and North Cascades.  Read more about fisher recovery here.

Weasel: There are two species in the Methow- the Short-tailed Weasel (Mustela erminea) and the Long-tailed Weasel (Mustela frenata).  Some call the short-tailed weasel by the name ermine.  Weasels have a long slender body, long neck, long head, and long vertebrae, all of which they compress and then extend in long bounding strides, like a slinky toy, when they move. In winter, they develop a white coat.  They have a huge appetite, and must eat at least 1/3 of their body weight per day. Their resting pulse is 480-500bmp.  The subnivean zone (below the snow but along the ground) is their key to survival in winter. Their size and shape are hugely inefficient for cold weather, so they stay under the snow most the time except to hunt.

Methow photos from Gary Ott of a short-tailed (?) weasel getting a mouse.

The American marten or pine marten (Martes americana) are found in dense coniferous forest at higher elevations in areas with cold, snowy winters, similar to lynx. Like other mustelids they were highly valued as furbearers, and Okanogan County was an area of extensive trapping, even up until the year 2000.  They feed on rodents, insects, birds, eggs, fruits and nuts. Though marten are well-adapted for snow, their activity is greater in summer than in winter, and they use the insulating characteristics of snow to keep warm and dry in the winter.  They will often be in the subnivean layer and use areas of shallow snowpack.  Marten are smaller in size and lighter in color than fisher, and we may begin to see these two species in the same areas after fishers are reintroduced in the North Cascades later this year!

Wolverines are the ultimate alpine survivor, but they could be the next victim of climate change. Their Latin name Gulo gulo has to do with how much they eat and how much they destroy.  Considered ferocious and with strength out of proportion to its size, a wolverine is a powerful and versatile predator.  Though they typically feed on ungulate carrion (they are primarily scavengers), marmots and other small mammals, they can kill prey much larger than themselves.  Males are typically around 30lbs though they can be much larger, and females around 20lbs. They have large feet and claws, frost resistant fur, and are thermo-neutral down to -40F.

Wolverine skulls don’t have a detachable lower mandible, it is locked in with bone so that when it goes to crush a big bone it doesn’t dislocate it’s jaw.  They have very large home ranges and are capable of traveling long distances. They are habitat generalists avoiding humans.

Like other mustelids, wolverines mate in the summer but have delayed implantation.  They give birth in late February in a den deep under the snow in the peak of the winter during the harshest conditions. Their successful reproduction appears to be tied to deep snow layer that persists through spring. Natal dens in the North Cascades have been found at 6000 feet.  Two to three kits are born.  Sometimes, males will go to the den sites to visit the kits and to scent mark the dens where they have made offspring. It’s believed that wolverines might cache food in summer snowbanks to survive food scarce winters, which may be especially important for pregnant and nursing females who can’t go on long hunting forays.

The North Cascades Wolverine Project
spanned from 2006-2015. There are other research efforts still ongoing in Glacier, Yellowstone, and central Idaho.  The first year of the study determined that wolverines can effectively be live trapped and radio collared!

What do you do with them?  Tranquilize them, then take size measurements, DNA and other health assessment, and diagnostic photographs to capture the unique pattern on their chest/throat. Each get a unique combination of colored ear tags and a radio collars.  Their body temperature and other vitals are taken during the 45 minutes or so that they are under.  Then they are placed back in the trap before they wake up.

Do they ever attack you? No, they run away the moment they are released.

What did we learn? Ultimate alpine survivor is a good name. They inhabit high elevations year round and travel great distances.  DNA evidence suggests that they were totally extirpated from the western US and that they trickled down from upper Alberta. The research provided that spring snow cover until May 15th is the best predictor of where they can thrive. Currently they are only found in North Cascades and Northern Rockies in the United States.

See a wolverine release video here!

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