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Pennsylvania’s white-tailed deer and their amazing adaptations

The “whitetail” is our official state mammal and one of the most admired by outdoor enthusiasts and most pursued by hunters. With so many hunters “after” them and so many highways and streets to cross, it is a wonder so many survive. The answer to that: they have wonderful adaptations. I am particularly amazed at how well deer have adapted to living in or around the many housing developments now so common in much of their forest homes.

The whitetail is a ruminant, much like our domestic cow. A ruminant has a four-chambered stomach which serves them well because a deer can quickly “gobble down” food where it may be more exposed to predators. Later, in a more hidden/secluded area, the deer will now bring back the food from the rumen (first stomach region), chew its cud, and then it will pass it on to the other stomach chambers for straining and then digesting. I regularly have observed “bedded” deer chewing for a few hours after they have lain down. Obviously this adaptation keeps them in a safe location longer and less time exposed to danger.

Deer, of course, have more crucial adaptations. Arguably, deer’s senses have enabled them to be so successful. A deer’s sense of smell is legendary.

Any archery hunter can attest to a sudden shift of a breeze carrying the human scent to a deer and watching it stop in its tracks and almost instantly bolt away from danger. This sense of smell is vital to male deer, when in the breeding season they wander, trying to detect the scent of a female ready to breed.

Deer have excellent eyesight, too. They are quite adept at noticing the slightest movements.

However, they are basically color blind because their eyes have fewer receptors for color but more light-gathering receptors to capture the slightest amount of light to move effortlessly in the dark. Imagine yourself trying to run as fast as you can through the forest and not tripping or running into trees.

If you are a hunter or camera enthusiast, you know that a deer’s sense of hearing is outstanding, too. The slightest noise like a twig breaking or shuffling a backpack quickly alerts them to possible danger.

The deer’s fur is special as well. Deer, in summer, grow hairs giving it a reddish/brown color and making it much more lightweight. However, as fall approaches, whitetails gradually replace the summer hair with more gray/brown hairs. These heavier hairs are much thicker and each hair is actually hollow. This adaptation gives them an unbelievable insulating fur coat.

A deer can lay down in the snow for hours, and other than compressing the snow, will not even melt it. This is imperative for a mammal that doesn’t go into a den or nest, but is exposed to wind and often well-below-zero temperatures. The changing colors of the fur also help it blend in better with its surroundings.

It is quite adapted to matching the duller colors of fall and winter and even a snowy background.

Whitetail deer fawns are born spotted. This is vital to their survival for the first few weeks of their lives.

Shortly after giving birth, the female deer moves away from its fawns, and the fawns (apparently inherently) remain motionless.

The fawns, about 4 or 5 pounds at birth, are still not strong enough to move about with the doe, nor could they out run a predator. The dappled spot pattern is key to breaking up their outline and helps them to almost melt into the sun-dappled pattern of sunlight on the forest floor.

Today, an increased coyote and bear population is reducing fawn survival rates though. Fortunately, a doe normally gives birth to two fawns and occasionally three. The youngest and oldest doe more often have a single fawn.

Deer, of course, have adapted by having long, thin legs which are critical to enable them to navigate so easily through thick vegetation.

They are essentially running on their toes. These thin legs allow them to move easier when deep snow cover blankets the winter forests.

Whether you are a hunter, or as most of us, just enjoy observing nature, deer provide us quite a bit of entertainment. Hopefully, knowing how the deer’s amazing adaptations allow them to be so successful, you’ll appreciate their survival techniques even more.

But remember, as much as they have adapted to survive in the wild, they cross highways often with very little ability of judging a vehicle’s speed, etc. You need to be careful to avoid collisions in evening, nighttime and morning hours when they are most active. Keep those eyes open while in the outdoors to enjoy seeing our “whitetails,” and open as well as you drive.

Test your outdoor knowledge: Did you know that are deer herd around ___, was so low that the Game Commission transported trapped deer from other states to “restock” Penn’s Woods. A. 1850, B. 1910, C. 1940, D. 1990

Last week’s trivia: Evening grosbeak

Fawns, such as these closely following their mother, will remain with her until just before she gives birth again in May. Sometimes a fawn born very early in May may be mature enough its first autumn to breed and give birth also the following May. BARRY REED/SPECIAL TO THE TIMES NEWS
This fawn, photographed in August, already shows signs of her spotted coat fading.
This doe’s ears and eyes have alerted her to my presence from about 80 yards away.
A deer’s summer coat is much different from its “winter wear.” Note this doe is munching on a small branch with leaves. Deer are adapted as browsers and not grazers, surviving best on tender shoots and buds.
These deer, with their winter brown/gray color, blend in nicely with November’s and December’s drab landscapes.
This deer, on a 10-degree late January day, bedded down in 1 foot snow, even more comfortable with a bit of sunlight warming her.