Playful Prey

Playful Prey

Playful Prey

6 minute read –
As many of us know from watching our dogs, cats, or children at home, young animals love to play and they play often. Play behaviour has been observed in many mammals and even in reptiles1Burghardt, G. M. (2015). Play in fishes, frogs and reptiles. Current Biology, 25, 9-10. and octopuses!2Kuba, M. J., Byren, R. A., Meisel, D. V., & Mather, J. A. (2006). When do octopuses play? Effects of repeated testing, object type, age, and food deprivation on object play in Octopus vulgaris. Journal of Comparative Psychology, 120, 184-190.   While you and I can easily imagine what play looks like, researchers still want to learn more about the function play serves in an animal’s life.
Young animals love to play and they play often. Play behaviour has been observed in many mammals and even in reptiles and octopuses!  Seen here at Yukon Wildlife Preserve, lambs of Thinhorn mountain sheep frolic in the spring sunshine.
The majority of play in wild animals occurs when the individual is young, then becoming very infrequent (if occurring at all) in adults. Other behaviours are either expressed throughout an animal’s entire life such as eating, sleeping, and social behaviours, or are expressed at a certain time due to biological constraints, like mating behaviours that only occur when an animal is capable of reproducing. But play itself isn’t constrained by biology, so being concentrated during a particular time makes play an extremely unique behaviour that must have some key role in the animal’s development.
Play also often resembles other behaviours that show up later in life.3Pellis, S. M., & Pellis, V. (2009). The playful brain: venturing to the limits of neuroscience. Oxford, U.K.: Oneworld.  Think about puppies that jump on each other with their mouths open, teeth showing, and playfully going for each other’s necks, or kittens that quietly hunch down and pounce on a toy. These animals are essentially practicing for either settling dominance disputes between pack members or becoming a fierce predator respectively. Play in prey animals like ungulates (hooved animals) often mimics their predator avoidance strategies, which may be giving playful prey an advantage in survival.4 Byers, J. A. (1984). Play in ungulates. In P. K. Smith (Ed.), Play in animals and humans (pp. 5-41). Oxford, U.K.: Basil Blackwell.

Taking what we know about play and what mysteries remain to be revealed in specific species, I looked at the play behaviour in mule deer fawns to see if this pattern of play behaviour mimicking antipredator behaviour held in this species of deer.

To avoid losing fawns to predators in the summer, mule deer females rely on a good defense that often involves a coordinated effort of multiple females. In the winter, both males and females of all ages form large social groups which lowers their individual risk of being attacked. Knowing that mule deer adults are social and rely on being able to communicate with one another especially in stressful situations, the fawns should spend most of their time playing with each other to really build on these social skills, right?

What I love most about nature is that usually our simple assumptions don’t actually hold true.

In comparison with the closely related white-tailed deer, who use their speed and agility to out-run predators and will not defend their young, the fawns of both species played very similarly, instead of matching to their antipredator strategies.5Carter, R. N., Romanow, C. A., Pellis, S. M., & Lingle. S. (2019). Play for Prey: do deer fawns play to develop antipredator tactics or to prepare for the unexpected? Animal Behaviour, 156, 31-40.

So what is happening here?

Thinking back to the timing of play, when this behaviour is most common in an animal’s life is also when the cerebellum (the part of the brain responsible for movement and coordination) is undergoing the most growth and rapidly building connections between cells. This growth is influenced by the animal’s experiences at the time, leading us to believe that play may help with modifying the brain’s development by creating more connections in the cerebellum, increasing the animal’s ability to perform movements.6Byers, J. A., & Walker, C. (1995). Refining the motor training hypothesis for the evolution of play. American Naturalist, 146, 25-40.

The fawns followed the timing trend with the majority of play occurring when the fawns were less than four weeks old, decreasing as the fawns got older despite becoming more active during their days overall.7Carter, R. N., Romanow, C. A., Pellis, S. M., & Lingle. S. (2019). Play for Prey: do deer fawns play to develop antipredator tactics or to prepare for the unexpected? Animal Behaviour, 156, 31-40.

Figure 1. (A) The proportion of active time in which mule deer fawns of different ages played and (B) The average duration of active time for mule deer fawns at different ages.

During play, fawns spent most of their time running, stotting, and rapidly turning around while remaining close to their mom. Running and exploring the area where you are likely spending the most time, may give fawns the opportunity to learn how to navigate their surroundings and be better prepared to escape a predator.

Mule deer fawns also liked to perform chaotic twisty and twitchy movements during play that caused them to stumble around and almost lose their balance (though in a couple of instances the fawns did fall over!). These are what are known as “self-handicapping” movements in play and are thought to help a baby animal learn the limits of their bodies and how to correct themselves when they are close to losing their footing.8Spinka, M., Newberry, R. C., & Bekoff, M. (2001). Mammalian play: Training for the unexpected. Quarterly Review of Biology, 76, 141-168.

Figure 2. Sequence of self-handicapping movements during a fawn’s play.  Play Sketch based off of a video recording of play.

Imagine if a deer was trying to outrun a coyote, and that deer trips on a clump of grass. If that deer had spent time playing in a way that threw them off-balance, then they may have an easier time correcting themselves and continuing on, increasing their chance of survival.

Another part of the brain is involved here and that is the prefrontal cortex. This region is right behind your forehead and is responsible for planning, decision making, regulating emotions, and developing social skills.9Pellis, S. M., Pellis, V. C., & Himmler, B. T. (2014). How play makes for a more adaptable brain: A comparative and neural perspectives. American Journal of Play, 7, 73-98.  Animals who are not given the chance to play show an increased stress and fear response when experiencing a novel situation and have difficulty interacting with other individuals as adults. The prefrontal cortex, like the cerebellum, undergoes a lot of growth and development when an animal is young, overlapping again when animals are the most playful.10van den Berg, C. L., Hol, T., van Ree, J. M., Spruijt, B. M., Everts, H., & Koolhaas, J. M. (1999). Play is indispensable for an adequate development of coping with social challenges in the rat. Developmental Psychobiology, 34, 129-138.

Instead of mule deer fawns playing to develop their specific antipredator strategy (using a coordinated defence against predators), play may more generally improve the fawn’s overall physical and emotional resilience as they grow into adulthood, gaining and refining the skills they need for their survival. The occurrence of play directly impacting survival has been found in grizzly bears,11 Fagen, R., & Fagen, J. (2009). Play behaviour and multi-year juvenile survival in free- ranging brown bears, Ursus arctos. Evolutionary Ecology Research, 11, 1-15. feral horses,12Cameron, E. Z., Linklater, W. L., Stafford, K. J., & Minot, E. O. (2008). Maternal in- vestment results in better foal condition through increased play behaviour in horses. Animal Behaviour, 76, 1511-1518. and mountain goats 13Théoret-Gosselin, R., Hamel, S., & Côté, S. D. (2015). The role of maternal behavior and offspring development in the survival of mountain goat kids. Oecologia, 178, 175-186. with the most playful cubs, foals, and kids being more likely to survive into adulthood.

Mountain Goat kid exploring its habitat at Yukon Wildlife Preserve.   The occurrence of play directly impacting survival has been found in grizzly bears, feral horses, and mountain goats with the most playful cubs, foals, and kids being more likely to survive into adulthood.

Playing by running and jumping around builds up the fawn’s strength, endurance, and coordination – all necessary for a prey animal’s survival. Also adding in those unique self-handicapping movements that twist and disorient the fawn may help to train them both physically and emotionally for dealing with unexpected, stressful situations akin to coming face-to-face with a predator.

Play is such a common and well-known behaviour that we see it every day and could point it out at any given time, yet in terms of its function for different animals, it remains a complex and fascinating behaviour. We think of play as a fun and relaxing activity yet it seems to have a critical impact on an animal’s survival by facilitating the development of crucial motor and cognitive skills.

So next time you are watching your pets play in the backyard or your children roughhousing in the living room, you can think of all the complex brain and motor skill development that is happening as well!

Rebecca Carter

Rebecca Carter

Visitor Services Coordinator

Rebecca joined the Wildlife Preserve in the summer of 2020 after moving from Manitoba to the beautiful and wild Yukon. Rebecca earned a degree in Biology with honours from the University of Winnipeg studying behaviour in mule deer (one of her top 20 favourite animals.. it’s hard to choose!). She loves connecting with others through nature and sharing stories and knowledge about the animals at the preserve with visitors.

867-456-7400
rebecca@yukonwildlife.ca

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Rehabilitation – A Wild Success

Rehabilitation – A Wild Success

Rehabilitation – A Wild Success

1 min video – 

This juvenile bald eagle came to the Wildlife Rehabilitation and Research Centre in early July after it was found near Icy Waters on Fish Lake road, seemingly flightless. 

An X-ray revealed an infection.  Dr. Maria Hallock started the eagle on a course of antibiotics

The eagle was X-rayed upon arrival and it was noted that the eagle was suffering from an infection in the right wing. Dr. Maria Hallock started a round of antibiotics hidden in food.  The eagle was very reluctant to consume the medication – finding the pill in the food and spitting it out, making its recovery challenging, to say the least. 

Performed after initial healing time and antibiotics bring down the infection that obscured the initial observation, this second X-ray showed a fracture to the ulna.

With more creative hiding of the medication, a week passed and a second x-ray was performed where the Animal Care team was able to see a clear fracture to the ulna, within a perfect setting and healing process.

After a  couple more weeks of antibiotics and rest – the eagle was moved to our outdoor flight pen where the individual could be seen by public.

Over the next few weeks the eagle built its flight muscles and strength with the goal of being released back in to the wild.

On August 21, the Animal Care team released the eagle successfully to the wild, in the MacIntyre marsh area, near the same location it was found.  It’s always incredibly rewarding to give wildlife a second chance at life in the wild.

Jake Paleczny

Jake Paleczny

He/Him - Executive Director/ CEO

Jake Paleczny is passionate about interpretation and education. He gained his interpretative expertise from a decade of work in Ontario’s provincial parks in addition to a Masters in Museum Studies from the University of Toronto. His interests also extend into the artistic realm, with a Bachelor of Music from the University of Western Ontario and extensive experience in galleries and museums.

867-456-7313
jake@yukonwildlife.ca

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Wetlands Habitats – Yukon Wildlife Preserve

Wetlands Habitats – Yukon Wildlife Preserve

Wetlands Habitats – Yukon Wildlife Preserve

13 minute 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, continuing with wetlands.

Wetlands are a vital part of Earth’s ecosystems and contribute a number of essential benefits for the land and all the flora and fauna that live on it. At the most basic level, wetlands act as a filtering system to produce clean healthy water for creatures and plants to consume. Wetlands are also the preferred habitat for a wide variety of creatures that range from the smallest of insects to frogs and other amphibians all the way up to include North America’s largest deer species, the Moose, which seasonally depend on the aquatic plants that grow in wetlands for a large part of their diet.

Many other species have evolved to live in wetlands for the numerous benefits they provide in terms of maintaining a reliable food source, protection against predators and wildfires. Wetlands act as a buffer between larger bodies of water and dry land, these places are often called interface zones. These areas also act to prevent flooding of the land as they buffer rising lake and river water levels and reduce dramatic erosion and physical impacts to other habitats.

Again, look beyond our majestic megafauna moose, there’s so much diversity to see in the wetland habitat. Where there’s water, there’s usually waterfowl of many types, including Trumpeter Swans, Canada Geese, Common Loons and a wide assortment of ducks who may visit with us for a few days to rest and re-energize during their migrations to and from their summer ranges each year. Some bird pairs may decide to remain and raise a family at the Preserve, so ducklings and goslings paddling behind mom is a common sight over the summer.

You also will see the many barn and tree swallows gathering on the wire fence taking a break before returning to their stunt flying in pursuit of flying insects. Numerous warbler and finch species and our non-migratory chickadees, red polls and sparrows are but a few you’ll have a chance to observe.  Blue birds fly over both the grassland and marsh habitats in search of food, as do small hawks like the Sharp Shinned, Sparrow Hawks, Harriers, and an occasional Screech Owl. Of course there are the varieties of gulls that spend the summer season inland and do a terrific job of keeping edible waste items in check.

The wetlands are abundant with insects and rodents making these areas diversely populated. Bald eagles often hunt ducks on the marsh and when they do, things happen very fast. The eagle will silently glide in over the fence and drop down to about a meter above the water using the air currents to avoid flapping wings and alarming any ducks in view. A successful capture is frequently announced by the rest of the duck flock quacking and taking to the air in a loud blusterous effort. Foxes and lynx also hunt the bird population in the marsh. They are often seen trotting quickly among the long grasses searching for duck nests from which they may steal an egg or hatchling to take back to hungry young kits waiting in their den. While they don’t particularly enjoy it, lynx can be accomplished swimmers and are sometimes found in the water in pursuit of ducks.

Keep a keen eye out in the marsh for muskrats that are infrequently observed swimming or grooming on a frost heave. There are no known beavers in the Preserve marsh, if you do see a large swimming creature it is probably a muskrat.

The marsh, and waters draining from it, are home to tadpoles, which become frogs, who also consume their fair share of a wide variety of insects. Examples include: water boatmen, beetles, mayflies, scuds (a small shrimp-like bug), caddis flies, blood worms, leeches and the most voluminous populace of them all – mosquitos. These insects are the beginning of the food chain which supports the many thousands of creatures in existence today, and some have been around for a very, very long time.

One of the Preserve’s apex insects is perhaps the most vicious predator on the property: The Dragonfly. These remarkable insects reached their evolutionary peak before the dinosaurs roamed the planet, and since that time they have changed very little because they have attained top status in their portion of the insect world and dominate. However, some believe the dragonfly’s life cycle is unbalanced and are being punished for something.

You see, dragonflies start their lives hatching from eggs underwater to begin their larval stage, when they are known as nymphs or naiads, During this part of their lives in the mud under the water they are voracious hunters and will attack other insects many times larger than themselves, they even hunt tadpoles and small fish. They eat all they can catch and grow larger and stronger. Here’s the part thought to be unfair.

Photo of dragonfly taken during the 2020 Yukon Biodiversity Bioblitz, held at Yukon Wildlife Preserve

Dragonflies live underwater as these top predators for up to three years for some species. Then, one warm sunny day they climb up a stalk of grass out of the water and begin a remarkable transformation from a ferocious water bug, into an adult to become one of the most accomplished fliers on this earth, The sad part perceived as punishment is that the adult dragonfly only lives for about three days before it mates and perishes according to Nature’s plan. Three years underwater living and fighting in the mud and only three days as an accomplished and dazzling flier, then, it’s life cycle completes, it perishes, it’s all done – it does seem unfair.

The winter season brings profound change to the marsh. Many of the summer residents have either migrated south or have found warm shelter for the winter months. Of course the water freezes creating a barrier between those that live under the surface and those that live above. Insects continue to grow, eat and thrive under the water, now much darker due to ice and snow blanketing the surface, blocking most of the sunlight. In winter moose, both in the wild and in the wetlands habitat at the Preserve, can no longer access the aquatic vegetation they enjoy so much and turn to other vegetation to support them. Alas, winter also impacts the vegetation that grows above the water and since moose are also very efficient browsers, they adapt in winter by browsing more of the plant than the tender bits at the ends of the branches they consume in the summer. Look at the bushes near the fence line in the moose habitat to see how well cropped they become over the winter season.

No water due to freezing temperatures means no waterfowl as they all migrated south before the cold weather arrived. This is also true of the many songbirds and migratory raptors who raised families throughout spring and summer. Mice and some other rodents adapt to the seasonal change similar to the rodents in the grasslands – they create tunnels to travel in, stockpile food in middens and raise their families. Just because it is winter does not mean they stop breeding and producing offspring.

The predator species that depend on the mice and voles in the marsh change their hunting strategies as well when the land is frozen with a layer of snow above. Foxes are often seen leaping into the air to pounce on their lunch the same as they do in the grass pastures. The wild foxes on the Preserve move from habitat to habitat many times a day as they patrol in search of food, which is much harder to find and capture during the winter season. Winter is obviously a greater challenge as ground squirrels are hibernating, small birds have moved away and snow cover impedes easy mouse hunting.

Moose will avoid the frozen ice of the marsh during freeze up and the spring melt so that they do not break through and become stuck in the mud just a short distance below this thinner ice, which can become quite sharp and injure their legs as they struggle to climb out. Therefore, they stay closer to the fence, and terra firma, for easy and safe walking.

The return of the spring sun, the resulting longer, warmer days and the melting of the ice and snow announce a new season for all the creatures that make a living in the wetlands. The changes occur quickly as creatures work hard to make the most of the warmer weather, as they have a lot to do in a short period of time. Some years there are only about 140 ice-free days between spring thaw and winter freeze up. Thankfully the days are longer allowing for more to be done beneath the Midnight Sun.

If they don’t already have one or if they are just reaching reproductive maturity, many animals will need to find a mate; also they must find or build a place to raise a family then nurture and care for their offspring until they are independent and know how to sustain themselves.

Some creatures must learn how to fly after they have grown flight feathers. All will need to learn how to acquire food, which means some will have to learn to hunt while others will need to learn to forage where the foods they require grow. All will need to learn what predators and similar dangers are and how best to avoid them.

It sometimes looks like an idyllic life to we humans, but in reality each day is a life and death challenge for wild creatures as they strive to reach maturity and have offspring of their own and the circle of life is completed.

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.

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Golden Eagle:  Scapular Fracture

Golden Eagle: Scapular Fracture

Golden Eagle: Scapular Fracture

This story was originally published August 8, 2020 in the e-blast newsletter to Yukon Wildlife Preserve’s membership.

Are you a member but don’t receive these email Newsletters?  Contact us at info@yukonwildlife.ca to update your email preferences.

Banner photo credit:  L. Caskenette

The golden eagle is a young one – it arrived on August 7th. Conservation Officers brought the eagle from Watson Lake to the Yukon Wildlife Preserve’s Wildlife Rehabilitation Centre.

Upon arrival the eagle weighed 2.3kg. It had a fracture to scapular (not much we can do just needs time to heal). With some rest time and observation the eagle was then moved to the large flight pen on August 11th. He weighed 2.6kg at that time. A healthy individual should weigh in around 4-5.5kg, while females are slightly larger and heavier.

This individual needs to gain some more weight to get stronger before it will attempt any flying. On Thursday, our Veterinarian, Dr. Maria Hallock weighed the eagle in at 3.25kg. Gaining 600g in the last two week is a positive sign of recovery. The eagle has been eating well – anywhere from 3-6 quail/day (each one weighing 200-250g). We will continue to monitor his weight and movement/behaviour. We expect to see him recover, fly and build up muscles to return to the wild, timing remains up to him!

The following update was originally published October 10, 2020 in the e-blast newsletter to Yukon Wildlife Preserve’s membership.

 What’s Up Yukon connected with us to get the latest story on the Golden Eagle that is in care at the Wildlife Rehabilitation Centre at the Preserve.  This eagle can be found working on his flight and recovering in the large outdoor aviary, as he overwinters with us at the Preserve!

The following update was originally published January 23, 2021 in the e-blast newsletter to Yukon Wildlife Preserve’s membership.

A Convocation of Eagles

Lindsay Caskenette

Lindsay Caskenette

Manager Visitor Services

Lindsay joined the Wildlife Preserve team March 2014. Originally from Ontario, she came to the Yukon in search of new adventures and new career challenges. Lindsay holds a degree in Environmental Studies with honours from Wilfrid Laurier University and brings with her a strong passion for sharing what nature, animals, and the environment can teach us.

867-456-7400
Lindsay@yukonwildlife.ca

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The Life of a Mule Deer

The Life of a Mule Deer

The Life of a Mule Deer

7 minute read – 

Watching how an animal behaves in its natural environment and towards other individuals has always been fascinating to me, but I could never have predicted that I would find myself crawling around the open prairie grassland to sneak up on mule deer.  

Mule deer are an indigenous deer species to North America, ranging from as far south as central Mexico up all the way up to Dawson City, Yukon along the western half of the continent. Across their range, mule deer tend to be found in more open habitats along forest edges, in grasslands, and even deserts.  1Sanchez Rojas, G., & Gallina Tessaro, S. (2016). Odocoileus hemionus. The IUCN Red List of Threatened Species: e.T42393A22162113. https://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T42393A22162113.en.

Rebecca spotting deer, in layered clothing to blend into the vegetation - Cora Romanow

A good friend and colleague of mine spent our summer days searching for mule deer fawns to watch how these little animals played and how much of their days consisted of playing.

A mule deer fawn’s life begins around late-May to mid-June, born to a female who is at least two years old. The fawn may be the only off-spring or may have a twin depending on the mom’s health and the amount of food that was available the previous summer.  A newborn fawn has spots on their fur which helps to break up their outline allowing them to hide in long grass. The little fawn will remain close to mom for their first summer, relying on mom’s milk for the first five months before they start to graze on vegetation, then becoming fully independent after a year2 Geist, V. (1981). Behavior: adaptive strategies in mule deer. In O.C. Wallmo (Ed.), Mule and black-tailed deer of North America (pp. 157-224). Lincoln, NE: University of Nebraska. .

For us to watch the deer’s behaviour without influencing them, we needed to be extremely stealthy.

Named for their large ears, mule deer are well suited for living on open and rugged terrain. When detecting a sound, their ears can move independently of one another to allow the deer to hone in on a sound. Their eyes placed on the side of their head allow them to have up to a 310 degree view around themselves.  3Wishart, W. D. (1986). White-tailed deer and mule deer. In Alberta Fish and Game Association (Ed.), Alberta wildlife trophies (pp. 134-143). Edmonton, AB: Alberta Fish and Game Association.

Both of these senses give mule deer an advantage in detecting predators (and us) from far distances, even up to 1km away!   4Lingle, S. (2001). Detection and avoidance of predators in white-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus). Ethology, 107, 125-147.   This is especially important in a wide open space where the predators are also able to spot their prey from afar.

We would hike into the prairie with all of the gear we needed – spotting scopes, tripods, a video camera and plenty of paper to document what we saw. We would wear clothing that matched the seasonal grasses (vibrant green in the spring transitioning to browns in the late summer), and layered different colours and patterns to break up our outline, just like the fawns do with their fur patterns.

At times we would make the deer alert to our presence. When alarmed, and especially when they were trying to figure out what type of animal we were, mule deer would stomp one of their front hooves on the ground, move around us to try to get a better view, and make repeated snort vocalizations. The sound of the snort and the stomp, along with releasing an alarm scent from a gland on their hind limbs, functions to alert other deer in the area to potential danger. Females were especially persistent with getting us to show ourselves, which at times we had to scare her away to prevent her from alerting every deer in an area.

Mule deer are generally more stocky and unable to run as fast as say a coyote. Typically, mule deer can reach speeds of 50km/h, but a coyote can run upwards of 70km/h, making it difficult for mule deer to outdistance them. Instead when threatened, mule deer will move on to steeper terrain if available nearby, bunch up together, and confront the predator.  5Lingle, S., Pellis, S., & Wilson, F.W. (2005)  Interspecific variation in antipredator behaviour leads to differential vulnerability of mule deer and white-tailed deer fawns early in life. 6Journal of Animal Ecology, 74(6), 1140-1149.  When a fawn is in danger of being attacked, they will let out a high-pitched distress cry that causes mom to become alert and quickly find her fawn and whoever is attempting to grab them. What’s interesting is that this call will attract all mule deer moms in the area to the fawn regardless of whether the fawn is their own or the fawn of another individual. The females will then group together and perform a coordinated attack using their hooves to kick and stomp at the predator.

Coyote seen looking for preferred prey like deer. A coyote can also camoflauge well into their landscape. 

We never got close enough to elicit this level of antipredator reaction, nor did we want to. We aimed to be quiet and unknown so we could slip in and out of an area without causing undue stress to the animals.

We watched the fawns from when they were born in May, to when they were becoming independent and lanky teens in the late-summer. During this time, we could also see the adult mule deer groups shifting as the seasons changed.

In early spring, pregnant females will stay separate from other deer to give birth in their home range area. Our team can reliably identify deer based on their features, such as markings or scars on the face and/or body, size and shape of the white rump patch, tail length and colouration, and antler size and shape if they are males. Using their distinct features, we could go back into an area year after year and find the same females and her fawns in their homes. The only presence that would really move the deer out of an area would be the grizzly bears and to a lesser extent, coyotes. It seemed to be a dance to figure out week by week where the deer had shifted to if the grizzlies had moved through. After the predators moved on, those same reliable females would take back their homes once more.

As the summer wore on, females and fawns began to come together and spend their time in small groups. There were areas we named “nurseries” where it seemed that the females dropped their fawns together before moving on to graze, apparently taking advantage of the collective antipredator strategy females use.

At the same time, the males were in the bachelor groups or the “dude crews” as we referred to them. They too would be in a consistent area, forming groups of usually 5-10 males of various ages and generally be pretty relaxed looking, staying bedded for the majority of the day. But while they may look lazy, they were really investing a lot of energy into growing their antlers and prepping for the rut (their breeding season).

During the rut, males and females will form larger groups together along with the fawns of that summer and the previous summer’s juveniles. Males fight for access to females who become receptive around the same time in mid-November (although there are some females who are earlier in October and some later into December)2. Into the winter, mule deer of all ages and both sexes stay together in large groups of up to 100 individuals. This is a safety in numbers game to protect them from predators, especially from coyotes whose only available prey are deer since the small rodents such as ground squirrels are hibernating. When spring comes around, the cycle of behaviour patterns continues.

mule deer bucks sparring, rut fall season animal behaviour

Mule deer seem to have an intricate life balancing the ongoing risk of predators, to solving dominance disputes with one another, to looking out for their babies, all influenced by their own individual personalities and the areas they call their homes. Watching animals can give us a new perspective on the animals that live amongst us, and let us know that they are just as complex as us and deserve to have wild spaces left for them to live.

Rebecca Carter

Rebecca Carter

Visitor Services Coordinator

Rebecca joined the Wildlife Preserve in the summer of 2020 after moving from Manitoba to the beautiful and wild Yukon. Rebecca earned a degree in Biology with honours from the University of Winnipeg studying behaviour in mule deer (one of her top 20 favourite animals.. it’s hard to choose!). She loves connecting with others through nature and sharing stories and knowledge about the animals at the preserve with visitors.

867-456-7400
rebecca@yukonwildlife.ca

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