Wildlife Viewing

Yukon and lagomorphs rodents and lagomorphs

Yukon’s 28 of native rodents and lagomorphs make Table of contents up a sizable portion of the territory’s small What are rodents and lagomorphs?...... 2 Least diversity. From the familiar Red of our boreal Kluane Boreal Forest forests to the alpine-dwelling Project...... 11 © Government of Yukon 2019 Collared , rodents and Lagomorphs...... 14 ISBN 978-1-55362-838-5 lagomorphs are found across ...... 15 Yukon’s diverse landscape.

Jukka Jantunen Aquatic rodents...... 16 For more information contact: Government of Yukon This guide first describes , Wildlife Viewing Program the general biology and and more...... 18 Box 2703 (V-5R) natural history of Yukon , , Whitehorse, Yukon Y1A 2C6 rodents and lagomorphs. mice and more...... 22 Species descriptions follow. Phone: 867-667-8291 Toll free: 1-800-661-0408 x 8291 Checklist of species...... 28 Unconfirmed species Email: [email protected] To learn more...... 29 and exotic species, Yukon.ca such as the House Mouse, Find us on Facebook at “Yukon Wildlife Viewing” are not included. Jukka Jantunen Much of the information in this booklet came from Rodents & Lagomorphs of by David W. Nagorsen and The Natural History of Canadian Meadow by Donna Naughton. We offer a special thank you to Cameron Eckert for the use of his beautiful photographs. Text reviews by Piia Kukka, Mark O’Donoghue, and Tom Jung were very helpful. Capital letters and common names In this guide, accepted common names of begin with capital letters to help readers distinguish between species. For example, a Red Squirrel is a species of squirrel, not necessarily a squirrel that is red. All photos are © Government of Yukon unless otherwise noted. Cover illustration by Catherine Deer. 1 What are rodents and Getting around lagomorphs? Rodents and lagomorphs have many ways of getting around their environments.

1. Walking on four limbs: the most common way of moving about.

Rodents and 2. Climbing: Red Squirrels are superb climbers, lagomorphs are two with powerful limbs and a long tail to help balance when groups of relatively small jumping between tree branches. are also mammals. All rodents and skilled climbers, with sharp claws and rough foot pads lagomorphs have prominent to grip branches. front teeth (incisors) used for 3. Hopping: Snowshoe leap using their large, gnawing, and sturdy cheek powerful hind legs and land on their smaller front limbs. teeth for grinding food. Incisors Tiny jumping mice also propel themselves into a hop grow continuously throughout the ’s life. Collared Pika using long hind limbs and feet, and a long tail for balance. Teeth can also help distinguish members of these two groups. Rodents have one pair of incisors in the upper jaw while 4. Swimming: While all Yukon rodents and lagomorphs lagomorphs have two sets, the second being smaller and can swim, only two species are highly adapted for moving Jukka Jantunen tucked behind the first. Other mammal species generally through water – beavers and . These animals use have six incisors in each jaw; humans have four. their webbed hind feet and large tails to swim efficiently.

Rodents 5. Gliding: Only the Northern Flying Squirrel uses this specialized form of travel. Thin membranes of skin stretch Rodents are a large and diverse group of some 2,000 species, between the front and hind limbs, and smaller membranes comprising about 44 per cent of all mammal species in the world. join the cheeks to the front limbs. By stretching all four Twenty-six native species of rodents are confirmed to live limbs to their full extent, flying squirrels can leap from trees in Yukon. and glide gently to the ground or to other trees. Jukka Jantunen Lagomorphs 6. Digging: Many rodents actively excavate underground Sometimes called burrows. They use these tunnels and chambers for protection “”, this order from predators, shelter from extreme weather, rearing young, is much less diverse and hibernating. Marmots and ground squirrels are with about 80 species particularly effective at digging. worldwide. Only two American Beaver species are found in Jukka Jantunen Yukon, neither of which are true rabbits.

Snowshoe 2 3 Red Squirrel nest Food and eating Food so nice Shelter and space Rodents and lagomorphs eat mostly they eat it twice Shelter is important for rodents and , including leaves, buds, bark, All lagomorphs and lagomorphs. Dens and burrows , and fruit. Fungi (mushrooms many rodents practice provide protection from predators and truffles) are an important food coprophagy. and extreme weather, and are a safe source for some species. Some rodents This is when an space for raising young and storing food. animal eats its own also eat insects, other invertebrates, feces to extract and young birds and hares. Underground additional nutrients. Many rodents dig underground burrows using iStock/megasquib Incisor teeth their strong front limbs. Burrows often have more than Beaver skull one entrance and some have multiple tunnels and chambers. These prominent front teeth grow Arctic Ground Squirrels construct elaborate burrows used continuously and feature a hard, outer nightly for shelter, housing young, and for winter . surface called enamel. This enamel contains iron, which gives a yellow or Above-ground nests orange colour to incisors. The inner Collared Pika build nests and food caches under fields of rock tooth surface is softer. Unequal wear in alpine areas. Bushy-tailed Woodrats construct dens of on these surfaces creates a sharp edge, sticks in rock crevices and abandoned buildings. useful for removing bark and clipping off twigs, grasses, Lodges and sedges. Both beavers and muskrats build sturdy lodges along waterbodies using sticks Cheek pouches and branches. Underwater entrances and ground squirrels allow year-round access to the dry have spacious pouches inside iStock/ReedDaigle nest chamber inside. Where water flows are too high for lodges, their mouths. This allows them beavers and muskrats will burrow into banks instead. to carry seeds and other food

to their burrows for eating later. Kieran O’Donovan Tree dens and nests

Bruce Bennett Red Squirrels often build conspicuous nests of twigs, Least leaves, and grass. The squirrels use these nests Chipmunk Every last drop… Collared Pika nest year-round and they often house newly-born Extracting sufficient energy and nutrients from squirrels in late winter. Chipmunks, tree green plants is difficult. Like all mammals, squirrels, and deer mice sometimes use rodents and lagomorphs do not have enzymes tree cavities for temporary shelter. to break down cellulose, the main sugar in The Northern Flying Squirrel will also plants. Instead they rely on fermentation nest in tree cavities and “witches’ in their caecum – an enlarged part of the brooms” – dense clusters of intestine – where micro-organisms break branches and twigs, caused down cellulose into usable sugars. by a localized growth disorder in a tree. 4 5 Pika hay pile Surviving winter Winter is a challenging time for rodents and lagomorphs in Yukon due to low temperatures and reduced access to food. Food caching Animals use various strategies to survive the cold, dark season. This tactic is critical to many species. Hibernation and torpor It reduces the need Most species remain active through the winter. However, some to search for food during rodents reduce their activity, body temperature, and metabolic cold, harsh weather – rate to save energy. These strategies are called hibernation an energy-wasting activity. and torpor. The Arctic is a “deep hibernator” Collared spend late summer and fall collecting and can reduce its body temperature to below 0º Celsius. grasses and other small plants to build “hay piles” for winter feeding. Pikas are territorial and will defend their hay piles Hibernation and torpor, what’s the difference? from intruders. Bruce Bennett Beavers and muskrats collect material, typically from Hibernation Torpor aspen trees, and build floating rafts of food for winter. Lower body Yes Yes These caches are accessible from underwater so the animals temperature are not exposed to severe winter weather.

Lower Yes Yes Red Squirrels gather cones from trees and store metabolic rate them in large piles called “middens”, which they aggressively defend from other squirrels. Duration Long term Short term (days to weeks) (hours to days) Northern Flying Squirrels and Red Squirrels are known to cache mushrooms in trees. Examples Arctic Ground Squirrel North American Other strategies for Hoary Deermouse surviving the winter Woodchuck „„ Growing thick winter . Meadow Jumping Mouse „„ Building insulated nests. „„ Nesting together in groups. „„ Confining activity to areas

Jukka Jantunen under the snow.

Arctic Ground Squirrel

Red Squirrel midden 6 7 Importance to humans Why they matter: ecological Humans have a long and sometimes complicated relationship importance and conservation with rodents and lagomorphs. Rodents and lagomorphs play a critical, As a food source foundational role in and natural food webs in the territory. Indigenous people in Yukon have used these animals for sustenance for a very long time. , Arctic Ground

Food for many Eckert Cameron Squirrel, American Beaver, and North American Porcupine were all consumed. Today, Yukoners still hunt and trap these Many carnivores prey on mice, voles, species for food, especially Snowshoe Hare. and lemmings. In particular, members of the canid family (, , For clothing and fox) and the family (, , ermine, and mink) Beavers and muskrats are the most important furbearing rodents benefit greatly from small rodents. in the territory. Soft, warm, and water-repellant, the hairy hides of these animals have been highly valued for centuries in making Raptors – birds of prey that hunt with hats, mitts and jackets. Today, the hides and fur of these rodents their feet – also depend heavily on these (and other species) are sold and used in Yukon, nationally, small rodents for food. Great Horned , and around the world. Northern Owl, and Boreal Owl, along with Red-tailed and Rough-legged As a pest are common avian predators in Yukon.

Unfortunately, our native mice and voles sometimes get Snowshoe Hares are the preferred prey of Lynx Great dismissed as harmful “rats”. However, very few actually use and population cycles of these two species are closely Horned human buildings; examples include deer mice and the linked. Great Horned and Northern Goshawks also have Owl Bushy-tailed Woodrat. Voles and mice can cause superficial a preference for hares. When hare populations are low, lynx will damage to lawns as they travel beneath the snow. Gardeners prey more on rodents, such as Red and Arctic Ground squirrels. also report crop damage from mice, voles, and hares. However, rodents and lagomorphs also produce Spreading seeds many benefits for the environment humans and spores depend on (see Why they matter: Chipmunks, voles, and ecological importance Health risk: and conservation squirrels eat mushrooms. on page 9). hantavirus The reproductive spores Hantavirus pulmonary syndrome is a pass through the animals, rare but serious illness. It is believed to be unharmed, leading to new caused by breathing in a virus carried by airborne fungal growth on the forest particles of urine, droppings, or saliva. In Canada, floor. Tree squirrels also the primary carriers of hantavirus are believed to be deer mice. collect and cache mushrooms For more information about hantavirus contact Government for winter use, spreading of Yukon Communicable Disease Control at 867-667-8323. fungal spores as they work. 8 9 Aiding in soil health Kluane Boreal Forest Tunnels made by burrowing species, such as the Arctic Ecosystem Project Ground Squirrel and voles, allow air, water and nutrients to penetrate soil. The droppings of these species also contain Southwestern Yukon is known as the Kluane nutrients, which enrich the soil for plant and fungi growth. region. It is a diverse landscape home to the highest mountains in Canada, glaciers, You can help Yukon’s wildlife several large lakes and rivers, and large tracts of boreal forest. It was here that Yukon’s Tell us what you see! largest field study of the inner workings of an ecosystem occurred. The Yukon Conservation Data Centre tracks the territory’s plants and animals. Five rodents are currently of particular From 1986 to 1996, researchers looked at this ecosystem from interest: many angles. They studied the composition and changes in plant communities, including herbs, grasses, shrubs, and trees. They „„ Collared Pika is threatened by climate change and examined herbivores dependent on these plants, and their predators. is legally listed as a species at risk in Canada. Researchers studied relationships between these three trophic „„ Ogilvie Mountains Collared is endemic to central levels – plants, herbivores, and predators – in detail. For example, Yukon, which means it is found nowhere else in the world! “who eats whom?” was a simple question to ask, but challenging „„ Woodchuck distribution in Yukon is poorly understood. to answer in a remote wilderness landscape with multiple species „„ Southern Red-backed Vole and Western Jumping Mouse that change food habits throughout the year. both have a restricted range and a small number of Researchers manipulated some ecosystem components to test observations in the territory. predictions of these relationships. For example, they installed You can report sightings of these and other species by: fences in some areas to prevent access by mammal predators such as lynx. The scientists could then study the impact of predators „„ Using the free the iNaturalist.ca website or app. on prey species, such as Snowshoe Hares, by comparing fenced „„ Contacting [email protected] or 867-667-3684, sites to natural sites. toll free in Yukon 1-800-661-0408, ext. 3684. Northern ecology research is daunting. Field work is expensive and long-term funding is difficult to obtain. Short, brutally cold Cameron Eckert Cameron Ermine carrying a winter days, and study sites blanketed in deep snow make Brown Lemming field work particularly challenging. In this context, the Kluane Boreal Forest Ecosystem Project was significant in its time scale (ten years) and spatial scale (one square kilometre blocks of boreal forest were experimentally manipulated). The studies have greatly increased our understanding of what influences the abundance of plants and animals in the boreal forest. The research findings and experimental designs of this project have also laid the groundwork for more research in Yukon’s boreal forest. Inquisitive scientists continue to work with Yukon communities to learn more about our natural world.

10 11 Cameron Eckert Jukka Jantunen Collared Pika Collared Red Squirrel Red Vole Average, adultweights are provided, where available. Source: Rodents&Lagomorphsof BritishColumbia. and lagomorphsand Yukon’s rodents Weights widelywiththeseason vary (species accounts) (species and withpregnant animals. Porcupine American North

Cameron Eckert Jukka Jantunen Lagomorphs Viewing Search for Collared Pikas in alpine areas at the edges of rock slides and piles. Sites with lush plant growth are preferred. Snowshoe Hare Listen for its call – a distinct “meeeeep” – used to Lepus americanus | 1.3 kg maintain its territory and communicate alarm. Jukka Jantunen Pikas are very difficult to see unless Report Collared The only hare in Yukon has long they are moving. Pika sightings to the ears and large, furry hind feet, Yukon Conservation which allow it to travel on top of Data Centre (see page 10). deep snow. Its hair is mostly brown in summer and mostly white in winter – an effective camouflage in the boreal forest. Porcupine Young are born in spring after a gestation period of about 36 days. North American Porcupine Females may have up to four litters Erethizon dorsatum | 9 kg each year and sizes vary. Two to five young is average. Care of the young is limited Chunky and slow, the North American Porcupine is well suited to to daily feedings from the mother for about a month. a life in the forest, with long, sharp claws and rough foot pads, excellent for climbing trees. Long, sharp, barbed quills cover Viewing porcupines – up to 30,000 on an adult. Quills usually lie flat The Snowshoe Hare is found in forests with dense, thick cover along the body, but stand up straight when the porcupine feels of young trees and shrubs, where it spends its days concealed threatened. While quills easily and passively become dislodged and resting. When wary, hares tend to stay still rather than flee. into would-be predators, they are defensive weapons. Porcupines They re-use the same pathways through the forest, creating cannot launch their quills at threats. corridors of packed snow or leaf litter known as “ runs”. Porcupines eat a wide variety of plants, but are specialized bark-eaters. They remove the rough outer bark of trees Collared Pika with the incisors – the lips close behind the teeth to prevent Ochotona collaris | 150 g Eckert Cameron the animal from swallowing this material. The porcupine then eats the softer, more The Collared Pika or “rock rabbit” lives nutritious inner bark. Eckert Cameron in mountainous areas, finding refuge in the cracks and crevices of rock Viewing fields and slides. Small and greyish, During May and June at with small round ears, pikas blend dawn and dusk are into their rocky habitat. excellent times to look for porcupines in and Pikas are not explorers, along forested areas. typically remaining within Drive carefully along 10 metres of their rock pile. Yukon’s highways – They spend their days collecting porcupines like the salt plant material including grasses, sedges, herbaceous plants, left over from winter and shrubs. Pikas store this food in “hay piles” which sustain road maintenance. them through the long alpine winter. 14 15 16 Castor canadensis Castor BeaverAmerican Aq members. other family signal to beaver alarm water –the slapping the sound of atail Listen for theloud results insightings. at thesetimesoften through beaver habitat soslowly paddling dusk, active atdawnand The animalismost to findbeavers nearby. and chewed tree stumps Look for dams, lodges, Viewing year’s young are born. family for twoyears, usuallydispersing whenthat based onamonogamouspairof adults. Young stay withthe Unlike most other rodents, beavers establish tightfamily groups the softer leaves, twigs, andbuds. They usesturdy branches asbuildingmaterialandeat trees by chewing through thestem withsharpincisorteeth. throughoutand alongwaterways theterritory. Beavers topple –beavers construct large damsandlodgesin well-deserved and webbedItsreputation hindfeet. as“nature’s is engineer” Yukon’s largest rodent hasalarge, flattail,small eyes andears, exposing much of their head and back. Beaversexposing muchof theirheadandback. swim lower, While beavers are bigger thanmuskrats andhave alarger, uatic r uatic paddle-like tail,these featurespaddle-like canbedifficult toseeon a swimming animal.Muskrats swim highinthewater,

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Jukka Jantunen Ondatra zibethicus Ondatra Common a family unitintheirfirst year. until atleast theirfirst autumnand often spendthewinteras of aboutamonth.Young muskrats remain neartheirparents Three tonineyoung are borninspringafter agestation period muskrats are more closelyrelated tovoles. withakeel. Whilesimilarinmanyways tobeavers,side-to-side the water. Itslong,hairlesstailisdistinct –scalyandflattened swimmer, hindfeet usingitspartially-webbed topushthrough Slow andungainlyonland,theCommon Muskrat isastrong protected area for asinglemuskrat tofeed in. dome withasmall airpocket within. Thiscreates asmall, whichoftenice andstuff plantmaterialintoit, freezes intoa of lakes andponds. Muskrats chew aholeinearly-season thin In winterlookfor “pushups” of vegetation inthefrozen surface of openwater alongshore isa“highway” for cruisingmuskrats. bulk of thewaterbody’s isstill frozen. surface Thenarrow swath a great month for viewing –shorelines are free of ice,butthe and lakes, often withaquaticvegetation intheirmouths. Mayis You canfindmuskrats swimming alongtheshores of smallponds Viewing

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Jukka Jantunen 18 Jukka Jantunen Glaucomys sabrinus Glaucomys Squirrel Flying Northern Sq and more and night and the occasional nocturnal raidnight andtheoccasionalnocturnal onbird feeders. Watch for smallshapesfloatingthrough mature forests at FlyingSquirrel are arare treatSightings of Northern inYukon. Viewing switch tolichensgrowing ontrees, whenfungiisnot available. Flying squirrels primarilyeatawidevariety of fungiandwill Great HornedOwls. other creatures particularly of thenight, makesBeing firmlynocturnal flyingsquirrels vulnerable to through theforest, although10 limbs andskinflaps, flyingsquirrels canglideupto50 metres ankle onboth sides of itsbody. Byjumpingandextending its large eyes andaloosepatchof skinstretching from wrist to FlyingSquirrelUnmistakable has yet rarely seen,theNorthern such astheWoodchuck, are lessfamiliar. Others, Marmot. such astheRedSquirrel andtheHoary the territory. Someof theserodents are routinely seeninYukon, Six speciesfrom thesquirrel family ui rre ls, marm ls,

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Tamiasciurus hudsonicus Tamiasciurus Squirrel Red Snowshoe Hares. branches. They alsoprey onbird eggs, young birds, andyoung andcachemushroomsRed Squirrels ontree are known todry forming amidden,which sustains thesquirrel through thewinter. seeds of sprucetrees. Asquirrel willheapconesintopiles, being thecentral feature intheterritory. They prefer toeat Red Squirrels are highlyterritorial,withafood “midden” (cache) tail andwhiteringaround theeye. settlements. You caninstantly make outtheprominent bushy The RedSquirrel isoften encountered inYukon forests and dismay of feeder-watchers. raid from bird feeders, muchtothe branches overhead. Thesesquirrels commonly Red Squirrels. Listen for theirstaccato inthe chattering Forests withWhiteSprucetrees are agoodplacetolookfor Viewing as “Squirrel Camp”, thislong-termfield experiment examines many aspects ofmany aspects RedSquirrel ecology. Studies have focused Kluane Lake insouthwestern Yukon. Affectionately known Since 1987, researchers have studied RedSquirrels near on changesinfood onsquirrel availability anditsimpact

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Jukka Jantunen Least Chipmunk A large, chunky rodent with minimus | 45 g Marmota caligata | 4.6 kg black-and-white hair, the Hoary Marmot is often seen and heard Substantially smaller than both the in mountainous areas. This marmot is known to make seven Red Squirrel and the Arctic Ground Squirrel, different vocal sounds, the most familiar being a high-pitched the Least Chipmunk displays five dark and four whistle signaling alarm to other marmots. light stripes along its back. Chipmunks survive Hoary Marmots live in family groups of an adult male, one or two winter using periods of torpor lasting 80 to 110 hours. adult females, and their young. Family members often share However, they remain underground during this burrows through the summer and season, building nests in excavated tunnels. typically hibernate together for Summer dens are typically in hollow logs or about eight months of the year. Jukka Jantunen stumps, rock piles, or excavated burrows Viewing such as old Arctic Ground Squirrel tunnels. Marmots live in alpine and Viewing sub-alpine regions. They are diurnal Search open forests of poplar and spruce for Least Chipmunks. (active during the day) and are most A few hours after sunrise and from mid-afternoon to sunset active in early morning and late afternoon. are good times to look. Watch for interactions among family members including play-fighting,

Arctic Ground Squirrel Eckert Cameron chasing, and grooming. Urocitellus parryii | 460 g Woodchuck Resembling a large ground A common sight along some portions of Yukon highways, the Arctic Marmota monax | 1.6 kg squirrel, the Woodchuck is usually Ground Squirrel is usually brownish-grey with light-coloured spots, frosted-brown or reddish-blonde although black-coloured individuals occur as well. While abundant in colour. Unlike its close relative the Hoary Marmot, the Woodchuck in alpine and tundra areas, ground squirrel populations is found in lower-elevation forests, meadows, and road in boreal forests of the Kluane region declined embankments. Relatively rare in Yukon, its range is thought

Jukka Jantunen in the late 1990s. to be a diagonal swath from Watson Lake to Dawson. Arctic Ground Squirrels are active, social rodents, Woodchucks are fairly solitary creatures. Young animals usually leave typically travelling up to 500 metres throughout their mothers after weaning at about two months of age. Adults are the day during spring and summer. This contrasts generally territorial, with males maintaining exclusive home ranges. with its winter behavior – a long, deep hibernation Unlike Hoary Marmots, Woodchucks almost always hibernate alone. lasting seven to ten months. Some individuals begin hibernating in late July Eckert Cameron Viewing Watch for Woodchucks at low Viewing elevations in well-drained open land. Roadsides, alpine meadows, clearings, and Roadside meadows and fields open forests are all good places to look for are favourite spots for Arctic Ground Squirrels. Search for their burrow this rodent. entrances – fresh, loose soil at an opening indicates the burrow is likely being used. Report April to August are the prime months. Woodchuck sightings to the Yukon Conservation Chipmunks sometimes use the same tunnel Data Centre (see page 10). systems as ground squirrels. 20 21 The Brown Lemming is found across the territory. It uses moist Lemmings, voles, mice and more meadow habitats in alpine and sub-alpine areas, as well as Arctic Yukon is home to 16 native species of lemmings, voles, mice, and tundra. This lemming prefers to eat fresh vegetation, year-round. jumping mice. Two additional species – the larger Bushy-tailed This is not a challenge during the lush summer growing season, Woodrat and Common Muskrat – are closely related to this group. but in winter it resorts to eating and frozen shoots of These rodents typically have a small body size – well under grass and sedge. This diet creates green scat, rather than the 50 grams for most species. black and brown droppings typical of other lemmings and voles. Together, these species fill a critical role in Yukon ecosystems as The Northern Lemming is a boreal species, found across a primary food source for dozens of mammal and bird predators. Yukon except in the far north of the territory. It prefers wetland Species such as , foxes, owls, and hawks depend on habitats and riparian sites (areas beside waterbodies), but is small rodents for survival. The populations of these predators sometimes found in drier locations. This lemming is perhaps the often fluctuate in direct relation to the populations of their prey. least studied and understood of all Yukon rodents. Viewing Lemmings In spring and summer search for Brown Lemming “runways” – 1. Nearctic | Dicrostonyx groenlandicus conspicuous travel paths worn throughout winter under the snow,

2. Ogilvie Mountains Collared Lemming | littered with plant clippings. Northern Bog Lemmings are thought Eckert Cameron Dicrostonyx nunatakensis to use similar runways created by Meadow Voles. 3. Brown Lemming | Lemmus trimucronatus | 65 g Look closely at the feet of any hawks and owls 4. Northern | Synaptomys borealis | 26 g you encounter. You might see a lemming tightly clutched in the talons. Ermine and a Brown Lemming The Nearctic Collared Lemming is the world’s most northerly rodent, found throughout the Arctic tundra of Canada, , and the north coast of Greenland. This lemming lives in the extreme north of Yukon, surviving winters with a thick, white winter coat. Its summer fur is thinner and a mix of dark and light colours. Populations of Nearctic Collared Lemming cycle drastically about Myth: every four years. Females produce up to three litters per year and young lemmings develop quickly. Lemmings routinely hurl Jukka Jantunen Little is known about the Ogilvie themselves from cliffs into the sea. Mountains Collared Lemming. No, they don’t. This myth has persisted for decades and ap- The only records are from two pears throughout popular culture. The 1958 Walt Disney film sites in Tombstone Territorial White Wilderness contributed to this falsehood. The film Park in central Yukon. It was shows lemmings toppling over a cliff into the sea. In reality, previously considered to be the sequence was staged using deceptive photography and a sub-species of the Nearctic humans forcedly herded the animals into the water. Collared Lemming, but differs in hair colour and skull size. Some lemming populations cyclically increase very quickly – population “booms”. The animals will then disperse across Report Ogilvie Mountains Collared the landscape, searching for food and adequate space. Lemming sightings to the Yukon Lemmings will swim across waterbodies they encounter and Conservation Data Centre (see page 10). inevitably some individuals will drown. This may be the small Nearctic Collared Lemming kernel of truth upon which the myth was based. 22 23 Voles

1. Long-tailed Vole | longicaudus | 44 g iStock/Weber 2. | Microtus miurus 3. | Microtus oeconomus | 44 g 4. | Microtus pennsylvanicus | 35 g 5. Vole | Microtus xanthognathus 6. Southern Red-backed Vole | Myodes gapperi | 23 g 7. Northern Red-backed Vole | Myodes rutilus | 25 g 8. Eastern | Phenacomys ungava | 32 g

Typically less than 50 grams, voles are coloured in different hues of browns, greys and reds. Until recently, the red-backed voles had the scientific nameClethrionomys . North American Deermouse Voles are found in a range of habitats, from wet meadows and marshy areas to forests and alpine tundra. Some species maintain travel routes called “runways”, which are marked by plant cuttings Mice and droppings. Voles are active through the winter in the subnivean space – the small gap between the ground and the snow. 1. Northwestern Deermouse | Peromyscus keeni | 26 g 2. North American Deermouse | Peromyscus maniculatus | 22 g Food preferences vary by season and species. Northern Red-backed Voles have similar tastes to humans, consuming , cranberries, and crowberries in late summer and under the snow With large, dark eyes, sizable round ears, and a long tail, in winter. is an alternate food source. Tundra Voles eat mostly deer mice are the rodents of fairy tales. While both species are sedges in summer and switch to roots and rhizomes in autumn. found in southern and central Yukon, recent genetic research Breeding often occurs under the snow in spring. Females can determined that the Northwestern Deermouse is more common reproduce in their first summer, often having one to two litters. around Whitehorse and the North American Deermouse is more Voles are short-lived creatures – about a year is typical. Few animals prevalent to the east and north of the city. The research also survive two winters. found a third potential species of deer mouse ranging from Haines Junction to Dawson. Jukka Jantunen Viewing Voles are found across the Deer mice are extremely adaptable, occupying a wide range of territory and some species habitats including forests, meadows, old burns, alpine tundra, develop mazes of runways and human dwellings. Their diet is similarly varied – they eat under the winter snow, seeds, nuts, fruit, green vegetation, spiders, and insects. similar to lemmings. Viewing Deer mice are perhaps most commonly seen as winter approaches and these rodents attempt to take refuge in human buildings. Fortunately, they are easy to capture and remove; Northern however, you must take precautions due to the health risk Red-backed Vole Report Southern of hantavirus (see page 8). Red-backed Vole sightings to the Yukon Conservation Data Centre (see page 10). 24 25 Jumping mice 1. Meadow Jumping Mouse | Zapus hudsonius | 17 g 2. Western Jumping Mouse | Zapus princeps | 25 g

True to their name, these small rodents are built for jumping, with long hind limbs, large hind feet, and a long, thin, whip-like tail. These features allow them to jump up to a metre in a single bound, which they do when alarmed. Jumping mice have an omnivorous diet of invertebrates, seeds, and fungi. In spring, they consume caterpillars and beetle larvae. In summer, jumping mice likely eat more Bushy-tailed Woodrat high-energy plant seeds in preparation for their winter Neotoma cinerea | 375 g (male), 330 g (female) hibernation.

Viewing With only a fleeting look, you could mistake the Bushy-tailed Gordon Court The Western Jumping Mouse has only been seen three Woodrat for a Red Squirrel. However, long whiskers and light times in Yukon – all three observations were along the grey or tan coloured hair help distinguish it from any members South Canol Road. More abundant is the Meadow Jumping of the squirrel family. Male woodrats have a gland on their Mouse, which is found in the southern half of the territory, chests that produces a strong and distinct odour. at least as far north as Mayo. Look for it in moist, grassy, Bushy-tailed Woodrats build dens from branches and other weedy meadows and in dense vegetation near water. vegetation. These constructions are critical to protect woodrats from predators and temperature extremes in both winter and summer. Woodrats frequently occupy human dwellings including old cabins, sheds, and shelters. They are somewhat infamous Western Jumping Mouse for hoarding objects in their nests including animal bones, owl pellets, and shiny “human trinkets” such as tin can lids. Viewing Look for stick nests built in rock crevices, caves, or under rock overhangs. Old abandoned buildings and outbuildings are good locations to search as well. Their Yukon range is not well understood; however, a woodrat nest was observed in Dawson in 2003, showing a possible northern extent.

Report Western Jumping Mouse sightings to the Yukon Conservation Data Centre (see page 10).

26 27 Checklist of species To learn more

Family Scientific name Common name Page Lepus americanus Snowshoe Hare 14 Ochotonidae Ochotona collaris Collared Pika 14 Rodents & Lagomorphs of British Columbia Rodentia David W. Nagorsen The Natural History of Canadian Mammals Family Scientific name Common name Page Donna Naughton Castoridae Castor canadensis American Beaver 16 Dicrostonyx groenlandicus Nearctic Collared Lemming 22 Ice Age Mammals of Yukon Dicrostonyx nunatakensis Ogilvie Mountains 22 Government of Yukon Collared Lemming

Lemmus trimucronatus Brown Lemming 23 Ecosystem Dynamics of the Boreal Forest: The Kluane Project Charles J. Krebs, Stan Boutin, and Rudy Boonstra Microtus longicaudus Long-tailed Vole 24 Microtus miurus Singing Vole 24 Unusual Beaver, Castor canadensis, Dams in Central Yukon Microtus oeconomus Tundra Vole 24 Canadian Field-Naturalist 124(3): 274–275 Microtus pennsylvanicus Meadow Vole 24 Thomas S. Jung and Jennifer A. Staniforth Microtus xanthognathus 24 Myodes gapperi Southern Red-backed Vole 24 Myodes rutilus Northern Red-backed Vole 24 Jukka Jantunen Neotoma cinerea Bushy-tailed Woodrat 27 Ondatra zibethicus Common Muskrat 17 Common Muskrat Peromyscus keeni Northwestern Deermouse 25 Peromyscus maniculatus North American Deermouse 25 Phenacomys ungava 24 Synaptomys borealis 23 Dipodidae Zapus hudsonius Meadow Jumping Mouse 26 Zapus princeps Western Jumping Mouse 26 Erethizontidae Erethizon dorsatum North American Porcupine 15 Sciuridae Glaucomys sabrinus Northern Flying Squirrel 18 Marmota caligata Hoary Marmot 21 Marmota monax Woodchuck 21 Tamias minimus Least Chipmunk 20 Tamiasciurus hudsonicus Red Squirrel 19 Urocitellus parryii Arctic Ground Squirrel 20

Source: Yukon Conservation Data Centre, 12 December 2018. Unconfirmed species and exotic species, such as the House Mouse, are not included. 28 Kate and Ian Warrick

Not your typical beaver dam

Beaver dams in the boreal forest are usually made of wood. Beavers place branches and stems of , alder, and poplar trees and reinforce them with mud and a small number of rocks. However, placer miners working north of Beaver Creek, Yukon discovered two beaver dams constructed in a very different manner – the primary building material was rock! Miners Kate and Ian Warrick alerted Government of Yukon biologists to the curious dams. In September 2010, biologists documented the dams and later published their findings. One dam was particularly impressive, composed of 90 per cent rocks, with individual rocks typically being 20–30 centimetres across. What motivated the beavers to use rock instead of wood? As the site was an active placer mine, much of the original forest had been removed and large, woody material was not available in the immediate area. The biologists guess the beavers simply worked with what they had easy access to: rocks. It’s also possible the small amount of willow and aspen shrub along the creek was more valuable as food to the beavers and so they used rock as an alternate building material. Regardless, these dams highlight the adaptability of beavers in altering landscapes to suit their purposes. For free distribution only.

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