White-Tailed Deer and How they survive in

winter

BY: Lindsey Keiser and Kimberly Berger

Body & Behavioral Adaptations to Winter Climate

Deer Yards Winter Food Threats to Survival Conclusion

SUMMER

WINTER

Most deer go into winter with some fat on their bodies. Amount is determined by the quality and

quantity of food available. They build up the fat reserves in

September and October. The way that they achieve this is by

searching out food with the most nutrition.

Examples are apple orchards, hay, and cornfields.

Basic Metabolism- measure of energy requirements. Heat production must equal heat loss.

Deer to not respond to cold in this manner. Their metabolic rate drops instead of speeding up

when the temperature gets below freezing. This rate requires a minimum calorie count

of 1,140 cal. Per 100 lbs. of body weight. With this low metabolism rate, deer will lose 12-

15 % of their body weight.

The parts of the endocrine system that are effected are:

Adrenals, pituitary, and the thyroid glands.

They are at there smallest and inactive during Jan. and Feb., the period of the coldest weather.

If the Temp. drop is slow and steady, the deer can adjust to the slowing down of their endocrine system more easily.

If the temp. drop is fast and severe they may go into shock and die.

During winter deer scrape away the snow to lie on the leaves underneath, creating a bed, this is counter productive. They burn more cal. Scraping the snow away, when

the snow would be more effective if it enveloped the body like a blanket, creating heat.

They spend 90% of their time in winter bedded down, and do little to no activities to conserve energy

Deer use these beds over and over again , and will even become territorial about their beds.

During a heavy snow fall they will lie down & not move unless disturbed.

Literally they are buried in snow

Deer Yards- are usually in dense evergreen swamps, draws, gulleys, or along brushy waterways. White tails travel no more than 2-3 miles to yard up

The max. distance they will travel is 15 miles. Main Objective-to get out of the wind.

Also in deer yards the snow depth is less because the snow gets caught on trees.

Also these spots are warmer then the outside climate due to the fact the trees holding the snow act as a insulator.

Not only is there a food shortage & physical stress, the deer yards have a tendency to become over crowded. Whitetails are not herd animals by nature, they

gather into herds only when forced to.

Aggression is very common among deer in the yards.

Examples of aggression are the bucks turning on the does and the does turning on the fawns.

They turn on each other because of food shortage. Dominance is always in a state of flux.

This is due to it always having to be reestablished at every contact because of the need for food.

Bucks are usually dominate because they are bigger and stronger then does

Because Bucks lose their antlers prior or during winter, they fight by kicking out at each other.

The growth of summer vegetation gives false impression that their food is plentiful.

It is important but the critical vegetation is that which is available during winter

Most deer revert almost entirely to brows because they are forced to.

Most herbaceous food is not available. They mostly search out small, nutritious twigs

The protein level of the plants drops as the plants begin to dry up.

Can drop as much as 25-40% Their digestibility also lessens In spring they can digest 70% of plants consumed, in

winter it drops as low as 12%

Deer are selective feeders. They instinctively look for the food with the highest

protein.

Deer need a mixture of forage types. The very best food will only sustain them for 2 wks.

White tailed deer love to eat acorns, oak leaves, whatever corn that has been lost to the picker, and rye grass.

Deer also get nutrition from the bark that they eat & not from the cellulose of the wood.

Two main threats to the survival of deer: Starvation & Snow depth’s effect on their movement.

Starvation is a major cause of white tail deaths during the winter season.

When easily reached food is gone, deer will stand on their hind legs to reach food on upper branches.

A 7-mon. fawn can reach about 5 ft., an adult doe can reach 6 ft., while an adult buck can reach 7 ft.

Naturally, this causes the fawn to get less food. The 7-ft height is called the “brows line”.

When food is gone from here it really means starvation

The legs of a average deer are 18-22 inches long.

Fawn legs are 16-18 inches

Deer can walk around in 15 inches of snow but can’t in 24 inches.

In deep snow deer must bound instead of walking.

This is very hard for fawns, and this leads to a high number of fawn deaths in winter.

In this presentation we covered Body & Behavioral

Adaptations to Winter Climate

Deer Yards Winter Food Threats to Survival