Thinhorn Mountain Sheep

Thinhorn Mountain Sheep

Thinhorn Mountain Sheep

10 minute read –
For a long time, it was believed that there are three distinct subspecies of thinhorn Mountain Sheep in North America each of these known as: Dall, Fannin and Stone. Each subspecies displayed different colouring of their coats where Dall would be pure white, Fannin would be white with grey, silver and black highlights and Stone sheep were white with brown and black highlights and sometimes predominantly all dark grey.

Thinhorn Mountain Sheep grow one set of horns from youth to old age.  Pictured are two rams (males).  L to R:  Young ram; mature ram.

Recent DNA gathering and analysis has revealed that all three subspecies are actually very much alike and identification of each subspecies is becoming significantly more difficult to confirm as interbreeding continues and identifiable traits or genetic markers blend together to produce a mongrelized modern day specimen.

Further, evolutionary biologists1https://www.ualberta.ca/science/news/2016/june/dna-analysis-rewrites-the-story-of-thinhorn-sheep-during-the-last-ice-age.html studying the lineages of thinhorn sheep have found evidence suggesting that the species diverged hundreds of thousands of years earlier than previously thought. Greatly influenced by the formation, movement and final melting of the glaciers, thinhorn sheep roamed a vast area in search of ice-free grazing areas known as refugia. The mountainous geography often separated groups of similar or same subspecies sheep where through isolation they accumulated some variances between populations over time, sometimes resulting in the formation of what were originally thought to be new subspecies due to variations of their physical appearance.

Genetic science continues to study these animals and new proofs are foreseen to reveal how the present thinhorn sheep populations of the Yukon, BC and Alaska evolved to be what they are today. As genetic scientists work with data gathered by paleontologists, geologists and other scientific disciplines, there is anticipated to be a more accurate understanding of how northern animals evolved into what they are today.

Despite their uniqueness in genes and variations in colour, thinhorn sheep rams share the same impressive set of horns that are admired in the animal kingdom. It is important to note that horns and antlers are not the same. Members of the deer family grow antlers which are shed and grow back each year, while sheep grow horns which are with the animal for all of its life. Also antlers grow from the tips while horns grow from the base.2https://medium.com/usfws/11-facts-about-antlers-18e689fe9e60#:~:text=Bison%2C%20antelopes%2C%20sheep%2C%20goats%20and%20domestic%20cattle%20%E2%80%94,from%20the%20tip%3B%20horns%20grow%20from%20the%20base  It’s a minor thing, but important because if a young sheep breaks off a tip of their horn, it will remain that way for the rest of its life. Female sheep or ewes also grow horns but these are much more diminutive than the male sheeps’ horns.

​ Female sheep or ewes also grow horns but these are much more diminutive than the male sheeps’ horns.

Sheep start to grow their horns shortly after birth and they will continue to grow over their lifespan, sometimes up to 20 years of age.3http://www.env.gov.bc.ca/wld/documents/thinhorn.pdf If you look closely at a ram’s horns you’ll see rings that circle the horn in various locations. These are called growth rings or annuli rings and a new one is formed each year and they are a reliable method to estimate the age of the animal. The horns are made of keratin, which is the same hard material that their hooves are made of and it grows quickly.

The first few inches of horn that a ram grows is called a lamb tip and represents about the first 6 months of the animal’s life,4https://www.adfg.alaska.gov/static/hunting/dallsheephunting/pdfs/dall_sheep_guide_to_judging_sheep_horns_under_full_curl_regulation.pdf it often gets broken off as the ram’s life of fighting and careless use take their toll.

Credit Alaska Department of Fish and Game
Each year a new annuli ring is formed near the base due to stressors the ram experiences, normally associated with the mating season.  You may notice that the space between the annuli rings is not uniform. This reflects the quality of nutrition that the animal experienced during that year of his life. Large wide spaces between the rings indicate good nutritional intake and low stress. Small thinner spaces may indicate a stressful year or a reduction in nourishment possibly associated with long, hard winters, forest fires and a loss of grazing, avoiding predators and similar stressors found in nature. Once the ram reaches a certain age of maturity, at about eight years,5https://www.coniferousforest.com/dall-sheep.htm the horns will continue filling out in thickness and mass, but stop growing longer as time goes on. A mature ram’s horns can weigh up to 15 kilos – more than all the bones in his body combined.
The size and shape of ram’s horns are what distinguish it from others and there is a wide variety of shapes, formations and sizes among sheep horns. Some horns form concise symmetric circles that are located close to the animal’s head, while others grow into a cork-screw-like shape where the tips are splayed out from the ram’s head. Some rams have horns that are thicker and longer than others, this is normally associated to a genetic trait of the animal’s ancestors where the influencing genes get passed to subsequent generations.
Hunting organizations such as Boone & Crockette have devised an elaborate measuring system with which to score the horns of most big game animals. The horns are measured at specific locations including the base, the overall length of the horn on each side, the distance between the horn tips and diameters of the horn in four key places. Once these measurements are collected some math is performed to arrive at the score for that ram’s horns. Records are kept by species so that hunters know how their harvested ram compares to others. This record keeping is also valuable for biologists and others to track the various changes in sheep populations around the world and may indicate declines in health, and their supporting environment and other influences which may be indicated by the changing size or condition of their horns.

Regional governments also utilize hunters to gather important data from the field. This is usually done by making it mandatory that certain parts of the harvested animal are submitted to the Game Branch as a condition of the species harvest tag. In this way biologists get to examine a diversity of a certain species all harvested within a quantified period of time and noted locations. Biologists examining sheep submissions here in the Yukon check for a number of important indicators. Yukon regulations require the complete head of a harvested ram be submitted for inspection.6https://yukon.ca/sites/yukon.ca/files/env/env-yukon-hunting-regulations-summary_en.pdf]]

The first thing they examine is if the horns are indeed a full curl as regulations prohibit harvesting a ram that is less than a full curl.

The biologists then extract a tooth to confirm the exact age of the animal by cutting the top off and counting the rings similar to the dendral or age rings of a tree. They may also take a tissue or blood sample to test for various diseases and infections the animals may suffer from. When all the tests have been completed the biologist bores a small hole in the top side of the horn facing the rear and epoxies a serialized aluminum plug into it. These plugs help to combat the underground trade of animal heads by having each head recorded by hunter, date and location.

Having access to all this data helps biologists to better understand the health of the wild sheep herds and may provide clues on where a disease is developing and which way it may be moving geographically.

Photo Credit: Kevin Pepper

Photo Credit: Kevin Pepper

Rams are famous for bashing their horns together to determine which is dominant for breeding purposes, but that is only for a few days each breeding season typically in late November and December. They also use their horns to communicate among themselves in ways that humans can only guess at. They will sometimes interlace their horns gently and rub their ears together which appears to be a welcoming gesture. Like most creatures, mountain sheep use body language to communicate with others. It may be a twisting of the head or extending their noses while they peel their lips back to reveal their teeth, or something as simple as their stance and how they wiggle their ears as they stare at others from a distance. They often grunt at each other as well.

Rams will often gently head-butt  each other as a form of greeting, similar to how a house cat bumps your leg when seeking attention. They can be quite gentle in their horn touching activities or they will get up on their hind legs and really lean into butting another ram with all the force they can muster.

Photo Credit Mark Newman

Photo Credit: Mark Newman

With remarkable muscle tone, balance and coordination mountain sheep demonstrate how well they have adapted to living on rock faces as they frolic and cavort in situations humans try to avoid. Often it will take a human significantly longer to cover a vertical climb it only took a few seconds for the sheep to navigate. Mountain sheep are remarkably strong and have endurance that allows them the energy and stamina to evade predators such as wolves and bears on the uneven and precarious mountain slopes they call home. Young lambs are a popular target for migrating Golden Eagles arriving in the spring season from their over-winter habitats. So sheep must be watching in all directions for potential dangers that could impact on them or their offspring.

Young lambs are a popular target for migrating Golden Eagles.  Ewes must be watching in all directions for potential dangers that could impact them or their offspring.

Mountain sheep have superior eyesight for distance and low-light conditions, they have horizontal pupils that help them to see panoramically to detect predators that could approach from different directions.  They also need to be able to see forward clearly so that they can run over rough terrain. They have excellent peripheral vision and can see behind themselves without turning their heads due to where their eyes are located on their skulls. Remember they need to look around their horns too.

Thinhorn Mountain Sheep are remarkable creatures perfectly adapted to thrive on the mountains of Northwestern Canada and Alaska and will remain a featured megafauna species here at the Yukon Wildlife Preserve.

Ram follows an Ewe closely.

Doug Caldwell

Doug Caldwell

Wildlife Interpreter

Doug is one of the Interpretive Wildlife Guides here at the Preserve. An avid angler and hunter he has a broad knowledge of Yukon’s wilderness and the creatures that live here. With a focus on the young visitors to the Preserve, Doug takes the extra time to help our guests to better appreciate the many wonders of the animal kingdom here in the Yukon.

Explore by Category

Explore by Author

Fall In to Autumn

Fall In to Autumn

Fall In to Autumn

5 minute read – 
Autumn is a season of change! It’s the bridge which helps us transition from summer towards winter. What a beautiful bridge it is, with leaves blazing colour in vibrant hues of red, orange and yellow. Fireweed has flowered and the leaves are crimson. Against this backdrop the first snows fall on the mountaintops.

Birds begin their migration back to their southern overwintering grounds, after a summer spent mating, nesting, rearing young, and eating well. Before we see the V’s flying overhead, we often hear them honking and calling to each other.

In the world of ungulates, it is the time of the rut. Antlered animals have finished growing this season’s antlers; their velvet has sloughed off and now they sport their hardened, ready-to-duel finery. We can see and hear as the males clash, challenging each other for the right to breed the females. Elk stags bugle, bull moose softly grunt – calling to interested females in the area and warning off competing males.

Watson, in the foreground, has shed the velvet on his first year’s full antler growth.

Those with horns are also clashing. This looks less like a duel and more like a train crash. Thinhorn Mountain Sheep rams, both Stone and Dall subspecies, run at each other and smash heavy horns together – the echo of this collision ricochets like a rifle shot. Muskox bulls have been rumbling since early August, chasing each other, establishing dominance and finally banging horns as they work to impress the females for breeding rights.
We begin to notice a lack of Arctic Ground Squirrel activity. We no longer hear the constant shrill warnings as nearby predators hunt; where are these industrious rodents? Hibernation comes early – females are already underground for the long winter ahead, and the last of the males aboveground continue to harvest and stockpile their midden, into early October. Predators such as Red Foxes can be seen traveling from one burrow-entrance to another…..looking for a disappearing meal of ground squirrel which used to be in abundance. Soon they’ll be gone completely, hibernating through the winter, under a thick layer of blanketing snow – but not just yet.

Autumn means hibernation is coming.  We’ve noticed a lessening of Arctic Ground Squirrel activity at Yukon Wildlife Preserve.

Humans are adding clothing layers, finding sweaters, mitts and toques in storage. We need these warm additions on the crisp, cold autumn mornings. Afternoon sunshine heats up; we turn our faces to the sun and shed those layers – it’s not winter yet! So too are the animals growing coats of winter fur, wool and hair. Mountain goats have spent all summer shedding last winter’s wool; almost immediately it’s time to grow in this winter’s layer of hair. Arctic Foxes are beginning to add some white to their brown and grey camouflage. They not only change colour with their winter fur, they also add seeming bulk. All those layers of white fluffy fur help them stay warm, maintain body core temperature and thrive in the harsh winter environment of the Far North.
Enjoying this short season is highly recommended – there’s nothing as seasonally relevant or celebratory as jumping into a pile of autumnal leaves. Cranberries are ripening, harvesting continues. Underneath the beauty of the changing season, there is a sense of urgency. Whether we are human or animal, we know winter is coming, and while it’s not here yet, time and opportunity are limited to eat, put enough weight on, or store food to survive the coming months.

Summer is over, the cycle continues. Autumn is the clear signal to prepare for what’s ahead. Fall in to Autumn; experience the sights and sounds with enjoyment, wherever you are.

Julie Kerr

Julie Kerr

Visitor Services Coordinator

Julie is a Registered Veterinary Technologist, living and working in Whitehorse since 2012. She joined the team in May 2018. She is passionate about wildlife, nature and living in a conscious manner with both. Her free time is spent outdoors observing wild animals and ecosystems; her connection to the natural world around her brings great joy – joy she loves to share with anyone interested. Honestly? Work and life blend rather seamlessly.

Explore by Category

Explore by Author

Mountain Slopes – Yukon Wildlife Preserve

Mountain Slopes – Yukon Wildlife Preserve

Mountain Slopes – Yukon Wildlife Preserve

11 min read –
The Yukon Wildlife Preserve features eleven iconic northern animal species, but if you look closely at each of the three primary habitats on the Preserve you’ll see many more species than “only” eleven. The three primary habitats include: grasslands, wetlands and mountain slopes. Each of these habitat types support animal and plant species that have evolved together over millions of years resulting in communities where they all make a living and contribute different values to the continuing health of their specific habitat. In this three-part series we’ll review each habitat and examine the greater community it represents, concluding with mountain slopes.

Mountain goats on their cliff habitat at Yukon Wildlife Preserve

Looking around the local landscape we easily see the topographic differences near to us and in the distance. These elevational changes of the geography influence how animals move, reproduce and make a living. Some have evolved physical adaptations providing them with advantages to live in different habitats compared to other species.

Some creatures have evolved to live on the rock faces of mountainsides, while others are better equipped to live in the valleys often near rivers and other water bodies. Some other species can live easily on all land types, like the Caribou that often travel great distances over all types of terrain along their migration paths.

 Caribou often travel great distances over all types of terrain along their migration paths.

The land all around us is in a continual state of change as it has been since time began. The Preserve is located within the Takhini River Valley. The river is south of us, only a few hundred meters away. Glaciers filled this valley up until about thirteen thousand years ago. While they were here, the glaciers altered the landform in some very dramatic ways as they bulldozed great areas of soil and rock, gravel and forested areas resulting in what we can see today. Look at the mountain tops across the valley and you’ll see the smooth rounded tops where the glaciers ground them down; and the other mountains with jagged and pointed tops indicating where the glaciers did not have a similar impact because they did not grow that high. However erosion is still at work as the influences of wind, rain, ice and snow continue to alter the landscape.

This type of landform provides a spectrum of variables that influence the safety, nourishment, and rearing of offspring that many species have adapted to over thousands of their generations.

Going back millions of years, many species evolved due to the influences of what they prefer to eat and where that food source could be easily found throughout the year. For example, beavers depend on wooded vegetation and while trees grow on mountain slopes, beavers had greater opportunity and benefit to feed on the vegetation that grows next to waterways, so beavers evolved to be more adept at swimming and thriving in an aquatic environment that also sustains certain species of trees that beavers adapted to thrive on.

Mountain Goats and Sheep are the megafauna species featured in the rocky habitats here on the Preserve, They evolved specialized hooves and muscle groups to allow them to move quickly, and safely, on the various rock types found on these slopes.

Of course there are numerous other species present here as well and while they have not evolved noticeable physical adaptations to live on the rocks, they have learned how best to live in this habitat and find the resources required to raise a family and make a living. Our ever-roaming foxes are often seen walking among the goats on the rock faces in their never-ending search for food. Many birds will nest on rocky crags and outcroppings as the precarious nature of these do provide some level of protection against predators like the fox. Eagles, hawks and owls often select a high perch on the rocks as they scan the area looking for their next meal. They often build nests in the protected areas in a crack high up a rock face to take advantage of these lookout positions.

Golden eagle nest on Lake Lebarge’s eastern shores early 2000’s.  Photo D. Caldwell

Rodents also make their homes within the jumbles of rocks hoping they have chosen a safe place to raise a family. Members of the weasel family, including Pine Martin, mink, weasels and even the cunning Wolverine will seek a suitable place to den among the rock slides as well as the forested areas nearby. Bears of course also seek out suitable places in the rocks to den and hibernate over winter.There are no bears denning on the Preserve at this time that we are aware of.

Also not present on the Preserve, are other creatures like Marmots and Pikas that typically make their homes high up in the rocks and mountains of the Yukon, Some species seem to be very widespread and can be found in a variety of Yukon habitat types. While some others are localised to specific geographic locations or elevations where they have the greatest opportunity for success. The ubiquitous Arctic Ground Squirrel also favours mountain sides to make a home.

Keep in mind that numerous natural influences like wildfires, landslides, avalanches and similar disruptions may alter the living conditions for a number of animals that will need to go in search of a new home to raise a family. The same may happen when a grizzly bear selects a den near a favoured grazing area of sheep or goats. To remain safe, the sheep will seek out a new grazing area well away from predators and other dangers.

Thinhorn Sheep rams enjoy sunshine in their predator-free grazing grounds at Yukon Wildlife Preserve.  In the background we see the sheep-accessible cliffs within their habitat.

Rocky habitats are not without their dangers. During the winter season ice will form in small cracks and crevices within the rocks, as the ice becomes colder and swells it further fractures the rock sometimes making it dangerous in that it may break away completely and fall further down the slope.

Gravel screes are the deposits of smaller rocks, pebbles and dirt that have fallen from above and form a skirt of loose materials at the base of a rock face. These can be difficult for mammals to walk on quietly and safely and as such provide another level of security for the creatures that dwell on the mountainsides. Flash floods caused by voluminous rainfall and spring snowmelt can also be dangerous for the creatures that live on the rocks.

Rocky habitats are not without their dangers, which change based on the season.  Here, Thinhorn Mountain Sheep walk through deep snow along the cliff edge at Yukon Wildlife Preserve.

Because rocks warm in the sun and hold that warmth after the sun sets, some rock faces are preferred by early arriving bird species, like raptors, that will nest there to get started on raising the offspring that may hatch while snow still lies on the ground. Raptor parents teach the offspring how and where to hunt after they have learned to fly. They have lots to do within a short seasonal weather pattern, so nesting in the warmth of the rock faces provides them with an advantage to raising a healthy next generation.

Like all other habitats on the Preserve, winter brings some profound changes to mountain slopes the animals must literally take in stride. The goats and sheep cannot run and frolic on the snow covered rock faces as they do in the ice-free season. They pay closer attention to where they travel and may use alternate trail systems during these times to prevent slips and falls. They still make it look much easier than it is and they sometimes look quite smug as they look down at us staring up at them from the road.

The spring thaw also introduces new dangers as the warming rocks may cause the ice to melt from beneath, creating loose patches that can break away when a foot is placed on them. Meltwater cascading down the slope is another seasonal hazard the creatures are well conditioned to avoid. Staying warm and dry is its own reward when the chill winds blow high up on the rocks.

As the ice and snow melt away and the winter white gives way to the browns and greens of spring and the migratory populations return for another summer in the Yukon, the many animals species return to raise their families and prepare them for a life that continues to transform and evolve due to climate change and the other forces of nature like earthquakes, wildfires, floods and the influences of mankind.

It may appear that some animal species are well established and very set in their ways, however they are evolving each day to maximize new opportunities provided by an ever-changing planet and the relationships between their habitats and their ability to get what they need to survive. We humans may not notice these changes right away as they can be quite subtle and appear meaningless to us. An example of this is the recent addition of crows and hummingbirds to the Yukon. They are expanding their summer ranges north as the climate warms and they can find enough nectar producing flowers to sustain them as they explore new habitats in the north. The flowering plants they depend on are also moving further north and their presence here will result in other changes that may take us some time to see and understand as they move into habitats presently occupied by the traditional species we normally focus on. Change is all around us, but it can be difficult to see clearly or understand the scope of these changes.

So take the time to look beyond the megafauna and other species we consider to be normal, you may see something astounding. Just ask Whitehorse bird enthusiast Cameron Eckert who found and photographed an adult female Calliope Hummingbird, on Herschel Island in June of 2017, 1,800 km north of its traditional breeding range.

Doug Caldwell

Doug Caldwell

Wildlife Interpreter

Doug is one of the Interpretive Wildlife Guides here at the Preserve. An avid angler and hunter he has a broad knowledge of Yukon’s wilderness and the creatures that live here. With a focus on the young visitors to the Preserve, Doug takes the extra time to help our guests to better appreciate the many wonders of the animal kingdom here in the Yukon.

Explore by Category

Explore by Author

Wild Spring Adventure!

Wild Spring Adventure!

Wild Spring Adventure!

6 minute read (and/or) watch the video!

Spring is the sign of new life! It’s the circle of life intertwined and flourishing from increased sunlight.

It’s a time of birds migrating. Some, like swans, stop only a short time on their way to nesting grounds further north; some stay for the season, like the chickadee and bluebird – they build nests, attract mates and raise their families.

There’s a saying – “Spring is in the air” – that implies a renewal of spirit and perhaps a bit of friskiness in certain species, like Red Foxes, that may lead to becoming parents to this year’s young (or perhaps they already ARE parents!). Of course, some species breed in the autumn, so that as spring progresses, we will start to see babies being born – at Yukon Wildlife Preserve we are hopeful that we will see Bison, then Caribou calves in the coming weeks and months. We expect to see wild fox kits and ducklings as well.

At the Preserve, Arctic Ground Squirrels started popping their heads above ground April 7 this year, with the males the first to break their winter hibernation. Juveniles and females are soon to follow their lead. We see, sitting on the cliffs and soaring above fields, birds of prey like bald eagles, coming in to hunt this prolific prey species. Spring is a notable return of the constant cry of alarm calls of ground squirrels, as their many predators hunt them from land or sky – displaying the full Circle of Life.

New growth has begun with grasses and early flowers like crocuses, to name only two plant species. This is important nutrition to many animals after a long cold winter, and grazers like Thinhorn Mountain Sheep can be found on south facing slopes, enjoying the tender new shoots, and the ease of eating, now that the deep snow has melted.

Crocuses are one of the first signs of spring – and important nutrition to many animals after a long cold winter.  Here we see a very early crocus found by the authors on their spring adventure hike at Yukon Wildlife Preserve.   Photo by Lindsay Caskenette

Water, water, water everywhere! Swans have returned with a splash – their honking fills the air with the best kind of noise as they stop over to feed while on their long migration to their northern nesting grounds . There is a year round marsh in the moose habitat at the Preserve, but the seasonal one next door in the mule deer habitat seems to be preferred by the swans – to the seeming curiosity of one of the female mule deer.  Everyone seems to love jumping and running through puddles, no matter how big or small the puddle…..or animal…..moose, humans and muskox! After a winter of conserving energy while food is scarce and energy is focused to survival, jumping in a puddle can lead to manic runs around the yard (or habitat). It seems spring can be about fun and burning off extra energy!

Swans have a long migration in the spring – open water at Yukon Wildlife Preserve is a frequent stop over for food and rest by migratory birds.  Some, like bluebirds, stay for the season, some, like the swan, typically move on to nesting grounds further north.  Photo Lindsay Caskenette

When you need a meal, sometimes you have to “spring” into action. Lynx are natural jumpers and we took the opportunity to provide enrichment to our resident lynx females by placing their food in trees. In the wild, lynx prefer snowshoe hare and will use powerful leaps to catch their meal within only a few “springs”….we mean jumps…..

Limited smells in winter mean that spring unearths a plethora of new scents on the air. Red Fox have an excellent sense of smell, making it easy for them to follow their nose to food sources. When they’ve eaten their fill, they will cache extra food as snacks for later. They keep an eye and ear out to avoid anyone following them to their cache site – other foxes and many birds in the Corvidae Family – grey jays, magpies, and ravens are known to steal their snacks.

Whether you’re human or animal, winter coats are shedding – and that wool, hair and fur can be found on the environment – rocks, trees, and fences (and sometimes finds its way into lining the nests of birds and small mammals like ground squirrels…..)  Shedding coats leads to a period of time not known for its fashion sense….and much shagginess in animals like bison.

Winter is over and the cycle of the year continues. Spring arrives, bringing increased sunlight and changes in everyone’s behaviour and appearance – humans and animals alike. We shed layers, feel the sun on our faces, enjoy the smells and the sounds of life renewing around us. We experience a rejuvenation of our spirits. Be well and enjoy spring, wherever you are.

Lindsay Caskenette & Julie Kerr

Lindsay Caskenette & Julie Kerr

Visitor Services Manager and Visitor Services Coordinator

Lindsay and Julie love to share the Preserve the same way they explore life – full on and full of adventure!  They have a collective love of:  Animals....Lindsay dogs, Julie foxes; Adventure.... Lindsay dog mushing, Julie extreme camping;  both take on animal personas during story telling.  Together they support the Preserve with a strong Visitor Services presence and often, they even get work done (this happens most often when the other one is out of the office).   

867-456-7400
 info@yukonwildlife.ca

Explore by Category

Explore by Author

A Thinhorn Sheep’s Case for Eating your Greens

A Thinhorn Sheep’s Case for Eating your Greens

A Thinhorn Sheep’s Case for Eating your Greens

Did you know you can tell a Dall sheep’s age by their horns? There are dark brown grooves on the curl of the horn of a ram that are called anulis. If you count those grooves they will tell you how old he is. Actually, those grooves will tell you how many winters he’s been around.

Horns on a wild sheep and a sheep raised at the Wildlife Preserve both experience a stunted growth in the winter, but there are differences between the horns. One of the biggest reason for those differences is because wild sheep and Preserve sheep have different diets. Let’s take a closer look at some of those differences.

In Kluane National Park and Reserve where I have the privilege of working in the summers, there is a mountain called Sheep Mountain, home to 400 Dall sheep who spend their entire life on the mountain. Those wild sheep rely heavily on 20+ varieties of grasses and sedges making up 46% of their annual diet. They also eat several varieties of willows and sages, especially the pasture sage (artemisia frigida) which grows abundantly all over the mountain. Together sages and willows make up over 30% of their overall diet. In the summer, in addition to fresh grasses, sages and willow buds, the wild sheep feast on fresh alpine flowers, berries, lichens and horsetails, and they get the nutrients they need. In the winter though, their diets is drastically reduced to mostly dry grasses and sages. Because it takes a lot of energy to grow horns and the food is more scarce and less rich in nutrients during the hardest time of the year, sheep’s horns stop growing during the winter, leaving a deep dark grooves in the curl.

At the wildlife Preserve, sheep are fed pellets containing a special formula with many of the nutrients they need to be healthy, and this on a daily base. Sheep at the Preserve are also less vulnerable to disease as they are vaccinated and cared for when sick. Although the growth of the horns is diminished during the winter and the rings can still be observed, they are not as obvious and well defined as the rings on the horns of a wild sheep. Comparatively, the size of the horns of a wild ram is generally smaller than the size of the horns of a Preserve ram of the same age.

The structure of the horns is also a bit different. The horns on a sheep at the Preserve are a lot smoother than the horns of its wild relative. The wild sheep’s horns are quite bumpy and the color is somewhat darker. This is also due to the difference between their respective diets. The formula given to the sheep at the Preserve have certain minerals that alter the chemical composition of the horns.

Sheep Mountain has become a popular destination for many outdoors lovers looking for the challenge of a good hike up to the  ridge, both for the amazing scenery and for the hope of getting a closer view at the sheep in their natural habitat. As this hike is attracting more and more visitors, the staff is increasingly doing more education about approaching the sheep. Hikers are asked not to come within 50 meters of the sheep, even when they are lying down, and to travel below them whenever possible. The sheep get very nervous when they perceive a threat and their natural instincts is to run up hill.  A few years back I was observing a lone ewe (female sheep), when she suddenly started bolting upwards on the mountain. Not to far behind and above her, a black shape came running and cut her off. It was a wolf and it was all over in no time. Since dogs can very easily be mistaken for a wolf, it is imperative for dogs to be on leash at all time. When the sheep are laying down they are digesting their food which has to go through 4 different stomach chambers in order to absorb all the nutrients they need. It’s a harsh life up on the mountain and the sheep only have access to fresh nutritious foods for about 4 months out of the year. They need to eat all they can to make it through the next winter and if they are constantly being distracted and interrupted while eating or digesting, they are not getting the nutrients they need to fatten-up for the winter.

Of course here at the Preserve the sheep are well feed and don’t experience many of the stresses of their cousins of the wild, including the risk of starvation or the stress associated with predators looming or human–caused distractions.

In any case, the next time you come to visit us, take a closer look at the horns on one of our beautiful ram and see if you can spot some of those rings. Can you tell how old he is?

 

This article orgingally appeared in the Preserve Post Quarterly Newsletter in Winter 2015. 

Johanne Maisonneuve

Johanne Maisonneuve

Johanne joined the Wildlife Preserve in the Fall of 2014 as a wildlife Interpreter in the winter. In the summer she is a visitor attendant at Kluane National Park and Reserve. Passionate about the outdoors, she has spent a lot of her time learning about the ways of the land throughout the Yukon in the 40 years + she has lived in the territory. A cabin dweller at heart, she now enjoys sharing her knowledge and experience with visitors from all over the world who come to visit the Wildlife Preserve. 

Explore by Category

Explore by Author