Small animals, including mammals, birds, and insects, play a substantial role in various ecosystems by consuming grass. For this discussion, “small animal” refers to creatures typically weighing under 20-30 pounds, such as rodents, lagomorphs, and various avian and insect species. Eating grass, or grazing, involves consuming the vegetative parts of grass plants.
Small Mammals That Graze
Numerous small mammals rely on grass as a primary food source, exhibiting adaptations to process this fibrous material. Rabbits, including cottontails and jackrabbits, are well-known grazers that consume large quantities of grass. They practice cecotrophy, re-ingesting specialized soft fecal pellets to extract additional nutrients from cellulose not fully digested on the first pass. This process allows them to maximize nutrient absorption from their grass-heavy diet.
Voles, often called meadow mice, are primarily herbivorous rodents that feed on grasses, stems, and leaves. These small mammals typically inhabit moist areas with dense groundcover, where grass is abundant. Prairie dogs, such as the black-tailed prairie dog, also consume significant amounts of grass, along with forbs and some shrubs. They favor fresh, green grass and may rely on stored dried grasses and seeds during winter months. Certain species of mice, like the meadow jumping mouse, include grass seeds and green plants in their diet.
Birds and Insects That Consume Grass
Beyond mammals, various birds and insects incorporate grass into their diets, utilizing different feeding strategies. Some bird species, such as Canada geese and sparrows, graze directly on grass blades or consume grass seeds. Young geese, for instance, pluck and eat grass, while sparrows often feed on grass seeds found in lawns and open areas. Finches and pigeons also consume grass seeds, which provide nutrients like chlorophyll, proteins, and minerals.
In the insect world, many species are dedicated grass-eaters. Grasshoppers and crickets are common examples, using their mandibles to chew on grass blades. Caterpillars, the larval stage of various moths, also feed on grass. Examples include armyworms and cutworms, which can consume significant amounts of turfgrass foliage. Additionally, the larval forms of certain beetles, known as grubs, feed on grass roots underground, disrupting the plant’s ability to absorb water and nutrients.
The Role of Grass-Eating Animals in Ecosystems
Small grass-eating animals contribute to ecosystems in several ways. Their grazing habits influence nutrient cycling by breaking down plant matter and returning nutrients to the soil through their waste. This process helps to fertilize the soil and support new plant growth.
These animals also play a role in seed dispersal, either by accidentally carrying seeds on their fur or feathers, or by passing viable seeds through their digestive tracts. Their grazing can help maintain grassland health by preventing overgrowth and stimulating the growth of new shoots. In the food web, small grass-eaters serve as an important food source for a variety of larger predators, including foxes, coyotes, owls, and snakes.