As a nature lover and someone passionate about deer, I’m often asked: “Do deer eat grass?” At first glance, it may seem like a simple yes or no question. However, the answer is a bit more complex.
While deer may occasionally graze on grass, it is not their first choice when it comes to sustenance. Grass makes up a very small part of a deer’s diet, usually less than 11%. Deer prefer nutrient-rich foods like forbs (broadleaf plants), browse (shoots, leaves, and twigs), and mast (nuts, seeds, fruits). Their digestive systems are not well-adapted to handle substantial quantities of grass.
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Why Deer Don’t Rely on Grass for Food
To understand why deer eat little grass, we need to look at the deer’s digestive system and nutritional requirements.
Deer are ruminants, meaning they have a four-chambered stomach that allows them to ferment and digest plant matter. However, the deer’s stomach is much smaller relative to their body size compared to other ruminants like cattle. Because of this, a deer cannot digest large quantities of grass as easily as cattle can.
Additionally, grasses tend to be low in protein and minerals compared to other plant foods deer prefer. Deer need nutrients and quick energy to be constantly on the lookout for predators. Their bodies are designed to maximize protein, carbohydrate, and mineral intake from the limited amounts of food they eat. Grass simply does not provide enough nutrition.
When Deer Eat Grass
Deer will eat grass when other food sources are limited. This occurs most often in late winter and early spring when the previous year’s mast and browse are gone. The protein and mineral levels of dried grasses are very low, but they provide some carbohydrates.
Deer also may eat freshly sprouted grass in spring because it is more palatable and higher in nutrition. Other grass species deer consume when available are winter grass, switchgrass, and panic grass.
Regional and Seasonal Variation in Grass Consumption
The quantity of grass consumed by deer varies depending on factors like geographical location and the time of year. Northern deer rely almost entirely on woody browse in winter when snow covers grassy areas.
During the growing season, deer eat very little grass, shifting their focus to more nutrient-dense forbs and browse. However, deer in agricultural areas may graze on cereal grains intended for livestock when available.
Plants Deer Prefer Over Grass
Rather than grass, deer focus their foraging efforts on plants higher in essential nutrients and more easily digestible. These include:
Forbs are non-woody, broadleaf plants that deer preferentially eat when available. They are high in protein and minerals and easier for deer to digest than mature grasses. Examples of forbs deer favor are clover, alfalfa, soybeans, and ragweed.
Browse includes the leaves, shoots, and twigs of woody plants. Trees and shrubs provide reliable browse year-round, especially important when forbs die back. Favored browse plants are oak, elm, maple, and hazelnut. The newest growth is the highest in nutrients.
Deer readily eat mast, or fruits and nuts, which offer carbohydrates and fat for energy. Acorns are a mast crop deer rely on in fall and winter. Additional examples of food sources for deer include hickory nuts, blackberries, apples, and persimmons.
|Food Category||Examples||Nutrients Provided|
|Forbs||Clover, vetch, soybeans||Protein, minerals|
|Browse||Oak, maple, elm||Protein, minerals|
|Mast||Acorns, apples, berries||Carbohydrates, fat|
Why Deer Digest Grass Poorly
To understand why deer get little nutritional value from mature grasses, we need to look at how deer digest plant matter as ruminants.
How Ruminants Digest Plant Matter
Deer and other ruminants have a four-chambered stomach that allows them to ferment and break down the cellulose in plants. The deer first chews and swallows its food into the rumen and reticulum chambers where bacteria start breaking it down.
Later, the deer regurgitates the partially digested cud back to its mouth to chew again. After more thorough chewing, the deer swallows the cud into the omasum chamber and finally the abomasum for further enzymatic digestion.
Grasses Require Long Digestion Time
Grasses are very high in cellulose and low in nutrients compared to forbs, browse, and mast. To extract nutrients from grass, microbes in the rumen need ample time to ferment and break down the tough cellulose fibers.
Cattle and other grass eaters have large rumens suited to the slow digestion of grasses. The deer’s smaller rumen size means grasses pass through too quickly for thorough nutrient extraction.
Deer Need Nutrition in Smaller Quantities
As prey animals, deer need to maximize nutrition from smaller quantities of food eaten periodically. They must also be ever-alert and ready to flee from predators. A gut packed with slowly digesting grass is counterproductive to their survival needs.
This helps explain why deer concentrate their feeding on smaller amounts of highly digestible forbs, browse, and mast. These foods provide quick-release energy and essential nutrients to keep deer healthy and alert.
When Deer Damage Grass Lawns
While deer gain little nutrition from eating mature grasses, at times they damage lawns, golf courses, or agricultural grass crops while foraging for more palatable plants. Here are some examples:
Seeking Forbs in Lawns
Deer often traverse lawns while searching for nutritious forbs like clover growing amongst the grass. The occasional nibble or trampling of grass is unavoidable. The use of clover-free grass seed and eliminating weeds may help reduce deer lawn damage.
Foraging in Alfalfa Fields
Deer may enter agricultural fields containing enticing alfalfa forbs interspersed among grasses. Again, the grasses suffer incidental damage from deer seeking more desirable broadleaf plants. Planting pure stands of grass crops avoids attracting deer.
Eating Grass Shoots and Sprouts
In early spring when food is limited, deer will eat the tender new shoots and sprouts of grass plants. Choose hardy grass varieties to withstand this temporary grazing pressure until other spring plants grow.
Deterrents to Keep Deer Away From Your Lawn
One approach to deter deer from munching on your beloved garden or landscape foliage is to plant them in closer proximity to your dwelling. Usually, deer are hesitant to venture close to humans and tend to avoid those particular areas. Conversely, plants that are less enticing to deer or susceptible to harm should be situated farther out on your property.
By the way, here’s everything you can do to deer-proof your garden. It’s important to combine different strategies to successfully keep deer our of your yard.
Deer are majestic creatures, but you don’t want them in your garden! Construct a fence that’s at least 8 feet high, made from heavy-duty material such as metal or plastic. You can also add a slanted top or double fence to deter them from jumping over. Remember to bury the fence at least 8-12 inches into the ground to prevent them from digging under it.
2. Use Deer-Resistant Plants
If you can’t beat them, plant things they don’t like. Deer tend to avoid plants with strong scents or prickly textures, so opt for fuzzy lamb’s ear, spiky yucca, fragrant lavender, and Russian sage. But keep in mind that no plant is completely deer-proof, so plant a mix of vegetables, herbs, and flowers to minimize their interest.
3. Motion-Activated Sprinklers or Lights
Motion-activated sprinklers or lights can startle deer and make them run for the hills! It’ll teach them to stay away from your garden. Sprinklers release a burst of water when it senses movement, while lights can make it harder for them to navigate around your garden.
4. Deer Repellent Sprays
Deer repellent sprays are an excellent option for the chemically-averse gardener. They use a combination of ingredients, including garlic, hot pepper, and eggs, to create an unpleasant taste and scent that will keep the deer away. But remember to reapply after rainfall to ensure it remains effective.
5. Hang Reflective Objects
Want to add some pizzazz to your garden while keeping deer out? Hang shiny objects such as CDs or aluminum foil strips. The reflection of light off these shiny items can confuse deer and keep them from coming towards your garden.
6. Physical Barriers
Protect individual plants or small garden areas by creating physical barriers, such as cages made from chicken wire or heavy plastic netting. Row covers are also effective in protecting sprouts and young plants from being eaten by deer.
7. Sound Deterrents
Deer have a keen sense of hearing, and certain sounds can frighten them away. Wind chimes or ultrasonic devices emit sounds that can deter deer from coming near your garden.
8. Smell Deterrents
Deer’s sensitive noses can be put to use! Human hair, soap, and rotten eggs are examples of strong scents that deer dislike. Spread these around the garden to discourage deer from coming close.
9. Natural Barriers
You can use nature to your advantage by planting holly or barberry bushes around the perimeter of your garden. Deer will avoid these prickly and thorny bushes. Alternatively, use a natural deer repellent such as bone meal or blood meal, which emit strong smells that deer dislike.
10. Clean Up Debris and Fallen Fruit
Old leaves, fruit, and debris attract deer, so clean up your garden regularly. By doing so, you’ll eliminate any potential food sources that might draw deer to your garden.
11. Rotate Your Methods
Deer are smart creatures, and they figure out how to outsmart your preventative measures. Rotate your tactics to keep them guessing. For example, start with building a fence, use sound deterrents or deer-resistant plants, then switch to natural barriers or deer repellent sprays. Keep mixing them up to keep them off-guard.
In conclusion, do deer eat grass? Deer eat very little grass overall except when other preferred foods are unavailable. Mature grasses provide limited nutrients and are difficult for deer to thoroughly digest. Deer focus their foraging on more nutrient-rich and digestible foods, mainly forbs, browse, and mast.
Occasionally deer damage lawns, pasture grasses, or agricultural grass crops while searching out tastier plants. But generally, deer do not rely on common grasses to meet their dietary needs.
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