Deer primarily consume plant matter, though they may occasionally eat insects like grasshoppers. While their digestive systems are adapted for a herbivorous diet, deer can be opportunistic, sometimes including small amounts of animal protein.
Typical Deer Diet
They are often described as “browsers,” feeding on the leaves, twigs, and shoots of woody plants, unlike grazers who primarily consume grasses. Their diet also includes forbs, which are broad-leafed herbaceous plants, along with various fruits, nuts, and fungi depending on seasonal availability.
A deer’s digestive system is adapted to process plant matter. As ruminants, they possess a four-chambered stomach that efficiently breaks down cellulose. Deer require a high-quality diet due to their quick digestive process, necessitating easily digestible forage to meet energy and protein needs. They selectively choose nutrient-rich plants.
Their diet changes throughout the year, reflecting the availability and nutritional quality of various plants. For instance, soft mast like berries becomes important in summer, while hard mast such as acorns provides significant energy in autumn. Over 85% of a white-tailed deer’s diet typically consists of browse, forbs, and mast.
Occasional Consumption of Insects
While deer are predominantly herbivores, they can exhibit opportunistic feeding behaviors, occasionally consuming insects like grasshoppers. They do not actively hunt them, but insects might become part of their diet through accidental ingestion. Deer may inadvertently consume grasshoppers while grazing on vegetation, especially in areas with high insect populations. Their broad tongues, used to gather plant material, can sweep up insects along with the intended forage.
Deer may also intentionally consume insects like grasshoppers to supplement their nutritional intake. This behavior is more likely during periods when preferred plant-based food sources are scarce, such as in winter or during droughts. Some studies suggest deer might consciously seek out protein-rich insects to help balance their nutritional needs, particularly during times of increased demand, like for pregnant or lactating does.
Nutritional Contributions
Insects, including grasshoppers, contain valuable nutrients such as protein and fats. They also provide essential amino acids, various minerals like iron, zinc, and magnesium, and vitamins, particularly B vitamins. The protein content in many insect species can exceed 60% on a dry matter basis.
Despite these nutritional benefits, the amount of insects consumed by deer is typically so small that it contributes minimally to their overall dietary needs. Deer primarily rely on plant matter for their energy and growth. Therefore, insects are considered a negligible or supplemental part of a deer’s diet.