The Mule Deer and River Otter page houses 46 images taken in autumn of Mule Deer near
the Northeast Entrance to Yellowstone and in the hills to the south of Blacktail Plateau, and
River Otters in logs jammed by a boulder on the Madison River near the West Entrance.

There are a few ringers on this page, as you will see below.

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Bighorn Sheep          Coyote          Moose          Mule Deer and River Otter


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Mule Deer Northeast Yellowstone 0237

A Mule Deer in the early morning at the edge of the forest near the Northeast Entrance to Yellowstone.

Mule Deer are named for their large ears, and like their relatives the Black-tailed Deer (now considered
to be a subspecies of the Mule Deer), they have a black tip on their tail. Along with the black tail and their
large ears, the primary differences between Mule Deer and White-tailed Deer is that Mule Deer are larger
and have antlers which fork as they grow, rather than branching out from a main stem as white-tailed deer.

As the Mule Deer from Yellowstone were only females and juveniles, I have added five images of
young males and mature bucks taken in Yosemite National Park and Bosque del Apache Refuge
to show antlers as they are erupting, in full velvet in summer, and bare antlers taken in mid-winter.


Mule Deer at Sunset Wawona 2758c

This detail crop shows a young male mule deer at Wawona Meadow in Yosemite National Park, with his velvet-covered antlers in an early stage of eruption from the pedicle.


Mule Deer Bosque 4120

Above is a male deer taken in winter at Bosque del Apache Wildlife Refuge in New Mexico displaying single-tine antlers.

Antlers grow from two pedicles, which are specialized bone-follicles on the head. Every spring, layers of cartilage called velvet antlers grow from the pedicles. Antlers grow faster than any other animal bone, and can grow up to an inch a day. They are covered with velvet, a vascular skin which provides blood, nutrients and growth hormone to the developing antler. Antlers grow from the tip, and the cartilage below is gradually mineralized into bone. Once the antler has reached full size, the velvet falls away or is rubbed off, and the bone dies. The mature antler retains grooves showing the path of blood vessels from the velvet.


Mule Deer in Velvet 1980

Mule Deer in velvet, taken in Stoneman Meadow in Yosemite NP in June. Note the bulbous shape
at the tips of the antlers in this image taken in mid-summer compared with the more pointed shape
of the velvet on the antlers of the deer in the image below, which was taken at the end of August. As
the year progresses, higher levels of testosterone slows the blood flow to the velvet, and the velvet
shrinks and begins to dry out. When the velvet dries, the buck begins to rub it off against trees to
expose the bony material below. The exposed antlers will be used for sparring and jousting for
dominance and mate selection during the fall rut, which occurs in October or November.


Mule Deer in Velvet Capitol Reef 7231

Mule Deer in velvet browse amongst the trees in the Johnson Orchard in Fruita, Capitol Reef NP.
Note the branched antlers of these mature male deer. Only male deer grow antlers (except reindeer).
The number of tines on an antler depends on how much nutritious food the deer eats while in velvet,
as well as genetic factors and the testosterone level, and does not depend on the age of the buck.

Antlers differ from Horns in several ways:

Horns are a layer of Keratin (like fingernails and hair) over a living bony core. Antlers are true bone structures.
Horns are slow-growing and permanent (not shed each year). Antlers are fast-growing and are shed each year.
Horns are usually grown by both sexes. Antlers are usually grown only by males (except for reindeer or caribou).
Horns are usually single tines, often curved or spiral, and exhibit annual growth rings indicating an animal’s age.
Antlers are associated with testosterone and are often branched. The number of tines do not indicate the age.


Mule Deer Bosque X3928 M

A Mule Deer buck in December at Bosque del Apache Wildlife Refuge in New Mexico.
The rut has ended by December, after which the antlers are shed to regrow in the spring.

All of the landscape (horizontal) large version images linked from the thumbnails are 1500 pixels wide.
Portrait (vertical) images are 1200 pixels tall (1290 pixels with title bar). Images designated with an “M”
in the shot number are 5:4 aspect ratio, 1500 x 1290 with a title bar, or 1500 x 1200 without a title bar.


Mule Deer Northeast Yellowstone 0251 M

A Mule Deer doe in the early morning sunlight near the Northeast Entrance to Yellowstone.

These images were taken at the end of September, about a month before the fall rut. During
September, the bucks are in the forest or brush, rubbing off the velvet and preparing their rack
for the rut which will occur in late October or November. Once the bucks have stripped off the
velvet, they will appear and begin to gather does and fight off other males they encounter.


Mule Deer Northeast Yellowstone 0256


Mule Deer Northeast Yellowstone 0263

Does and a juvenile Mule Deer in the forest near the Northeast Entrance to Yellowstone.

The fawns are born in the spring and stay with their mothers throughout the summer. They are weaned
after about 60 to 75 days, and generally separate before the fall rut in late October or early November.
Most does have two fawns, but first-year or second-year breeders sometimes have only one fawn.


Mule Deer Northeast Yellowstone 0258

A Mule Deer doe in the early morning sunlight, in the forest below the Northeast Entrance to Yellowstone.

Mule Deer have a distinctive white rump patch, a white throat patch, and a black-tipped white tail.
Males are larger than the females in girth, length and height, and can weigh up to twice as much.


Mule Deer Northeast Yellowstone 0258 M

A resized detail crop from the image above showing a Mule Deer doe in the early morning light.
Mule Deer are seen less often than other wildlife in Yellowstone. There are about 3000 in the park.

Mule Deer tend to move down from higher elevations in the fall as the temperature drops.
Mule deer are all over Yellowstone during the summer, but they migrate to lower elevations
in the fall, and in the winter they often move to ranges at lower elevations outside the park.


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Deer & Moose           River Otter & Rabbit


Mule Deer Tower Junction 9337


Mule Deer Tower Junction 9341

Mule Deer in the hills near Elk Creek on the Blacktail Plateau, between Floating Island Lake and Tower Junction.


Mule Deer Tower Junction 9348


Mule Deer Tower Junction 9350

You have to get away from the road a bit to find Mule Deer. In Yellowstone the distances between wildlife locations
can be so vast that you spend most of your time on or near the Grand Loop Road. This time, I took a little detour on
Blacktail Plateau Drive, which traverses the hills parallel to the Grand Loop Road from just west of Phantom Lake,
going south a bit to cross behind Crescent Hill, and rejoins the Grand Loop Road at Yancy Creek, just before the
little spur road which leads to the Petrified Tree (see the Assorted Scenic page). Blacktail Plateau Drive is far
enough into the hills that in some places you can occasionally see wildlife which will not approach the road.


Mule Deer Tower Junction 9359 M

A Mule Deer traverses a hillside covered with brilliant autumn foliage at mid-morning in late September.

Note the characteristic black tip at the end of the white tail of the mule deer.


Mule Deer Tower Junction 9365

A Mule Deer in the autumn scrub in the hills of the Blacktail Plateau west of Tower Junction.


Mule Deer Tower Junction 9366

A Mule Deer searches for succulent leaves while foraging a hillside on an autumn morning.


Mule Deer Tower Junction 9370


Mule Deer Tower Junction 9372

The deer sniffs a leaf to check its freshness, and decides it is ready to eat.


Mule Deer Tower Junction 9374

A Mule Deer munches some succulent autumn leaves while foraging a hillside
on the Blacktail Plateau, west of Tower Junction in Yellowstone at mid-morning.


Mule Deer Tower Junction 9377

A profile shot of a Mule Deer eating autumn leaves on a brilliantly colored hillside near Tower Junction.


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River Otter Madison River 9696 M

A North American River Otter and her four juveniles at play on their den, a massive group
of logs which have snagged on a boulder in the Madison River near the Seven Mile Bridge.

River Otters are members of the weasel family. These streamlined water weasels are equally adept
on land or in the water. They tend to create their dens in burrows they appropriate from other animals,
under logs, or in hollow trees or rock formations. They often evict beavers from their lodges, and log
jams like the one shown here are favored by otters to use as a combination den and playground.


River Otter Madison River 9703 M

A North American River Otter poses for a portrait on a log jam in the Madison River.

River Otters are hard to find, and this encounter was so interesting that it nearly caused me to
get flattened by a group of wandering Bison (see the story and images at the bottom of this page).

Otters spend up to 70% of their time in the den, and are often most active at dawn and dusk or at night,
so just finding five otters playing at mid-day was unusual. River Otters maintain large ranges and they can
travel long distances along a river in a short period of time. They are exceptional hunters, and are able to
successfully catch fish in about half of their dives. Otters can eat two or more large trout per day, and they
also eat crustaceans, bottom-dwelling fish, reptiles, amphibians, waterfowl, insects and small mammals.


River Otter Madison River 9705c

A North American River Otter explores a log jam on the Madison River at mid-day in early October.

River Otters are more social than most weasels. The basic social group is an adult female and her
offspring, although the family may also contain unrelated adults. Males tend to congregate together
in social groups, sometimes with ten or more individuals. Otter groups hunt and travel collectively.


River Otter Madison River 9708

A North American River Otter poses on its log jam den in the Madison River at mid-day.

River Otters often use beaver dams as dens, and occasionally share them with beavers.
This log jam is one of several in the Seven Mile Bridge area where logs catch on boulders.


River Otters Madison River 9714

Two North American River Otter juveniles at play on their log jam den in the Madison River.

Juvenile river otters love to play, and the chasing game is one of their favorite occupations.
Pups stay with their mothers for about 18 months, after which the mother leaves to bear and
rear another litter. Otter families stay close together for mutual protection to ward off predators.


River Otter Madison River 9717 16x9

A juvenile river otter follows one of its litter-mates along their log jam abode on the Madison River.

Like all of the 13 species of otters, the North American River Otter has a thick dense coat of oily fur
with an undercoat of shorter hair. The two layers trap air between them, providing effective insulation
against the frigid winter temperatures in Yellowstone. Otters constantly groom their coats to reduce
matting and to prevent fur from becoming flat, which impairs air circulation and insulating ability.


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Direct Links:

Deer & Moose           River Otter & Rabbit


River Otter Madison River 9740


River Otter Madison River 9741

A juvenile North American River Otter examines scents on the boulder behind the log jam, which they use
as a latrine site. Latrine sites are used as scent marking locations, an important method of communication.
Scent marked locations do not prevent other otters from entering an area or using the location as a den.


River Otter Madison River 9745


River Otter Madison River 9747

Two juvenile river otters examine scent marks on the boulder behind their log jam which is used as a latrine.
These scent marks signal species identity, advertise reproductive status, mark a territory and communicate
social status and identity to group members. Otters scent mark with glands on their feet and the anal sacs.


River Otter Madison River 9749

Two juvenile river otters examine scent marks on the boulder behind their log jam which is used as a latrine.
The long tapered tail of the North American River Otter is one third or more of the otter’s entire body length.


River Otter Madison River 9750 16x9

A North American River Otter stands atop the boulder behind its log jam den, used as a latrine and scent post.


River Otter Madison River 9768


River Otter Madison River 9810

The female river otter watches the juveniles at play and keeps an eye on the photographer across the river.


River Otter Madison River 9778c

The female river otter poses while watching the photographer across the way on the Madison riverbank.


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Direct Links:

Deer & Moose           River Otter & Rabbit


River Otter Madison River 9782

A female river otter poses while watching her four offspring play on the log jam they use as a den.
River otters typically bear one to three pups, but their litters can occasionally contain four or five.


River Otter Madison River 9785 M

A female North American River Otter watches the photographer from her log jam den on the Madison River.


River Otter Madison River 9801

The female waves to the photographer. Did I mention that river otters are social animals?


River Otter Madison River 9816


River Otter Madison River 9822c

The female otter slithers through the log jam, then pauses to take note of something of interest on the
northern bank of the Madison River to my left. It was about this moment that the hairs on my neck rose
and I noticed out of the corner of my left eye that the people around me were rapidly moving away...


Ron Bison Stampede Madison River 0062


Bison Madison Riverbank 9826

I turned (with my lens) and saw a string of Bison moving up the narrow riverbank towards me at a pretty good clip. I fired a quick shot (image 9826 above right), and considered my situation. The Bison were moving at about 25-30 mph and they were darned close. If I tried making it to the slope above the riverbank, there was a risk of tripping on a rock or a root and getting squished like a bug. The only option was to scoot as fast as I (safely) could towards the Bison, to get my back against a strategically located tree. I picked up my tripod and hustled over there, getting my back against the tree just as the Bison split to go around it. My friends had the presence of mind to take a few shots... image 0062 above left was taken just after I slammed my back against the tree. You’ll notice that the lead Bison is just starting to pass the tree.

The Bison all spooked as they went past the tree on either side, as they saw me out of the corner of their eyes, and believe me when I say that they were passing close beside me. They were moving pretty fast, and could not change course to do anything about the human in their peripheral vision, so I lived to shoot another day. Meanwhile, my friends were safely shooting the scene from atop the slope over the riverbank.

Just another day in Yellowstone.


Stampede on the Madison River SXL

A 2000 x 1027 version of the SXL Composite (4800 x 2464) which shows
your intrepid photographer hiding behind a tree on the Madison Riverbank
while a small thundering herd of Bison passes on either side of his refuge.

Below is a little Otter commentary to finish off this section...


River Otter Madison River 9802 M

The female river otter sticks her tongue out while waving to the photographer from a perch on her log jam den.


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Direct Links:

Deer & Moose           River Otter & Rabbit


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