The sight of birds actively foraging on a lawn often prompts curiosity about what they are finding in the dense turf. This behavior is driven by the availability of food sources, ranging from protein-rich subsurface organisms to various plant matter accessible at ground level. The lawn acts as a convenient and often abundant feeding ground. Understanding the specific targets of a bird’s search offers insights into the overall health and composition of the turf.
Lawn Pests and Soil Invertebrates
The most intense foraging activity, including repeated pecking or probing, usually indicates that birds are targeting protein sources beneath the surface of the grass. These high-value food items are typically the larvae of insects and other soil-dwelling invertebrates. Earthworms are a preferred source for species like American Robins, which locate the worms just under the soil and extract them with a characteristic tugging motion.
Larvae of ground-dwelling insects, commonly called grubs, are another significant draw for many birds, including Starlings and Crows. The C-shaped larvae of Japanese beetles and June bugs are especially sought after, as their fat-rich bodies provide substantial energy. Birds also actively search for leatherjackets, the tough-skinned larvae of the crane fly.
These larvae often feed on grass roots, making their presence a sign of a potential turf issue. Birds like Starlings will probe their beaks into the soil, creating small, circular holes as they hunt for these hidden pests. This behavior is particularly noticeable when the larvae are close to the surface, such as in early spring or fall.
Seeds, Grains, and Other Plant Matter
Not all bird foraging involves digging for invertebrates; a substantial part of their diet comes from exposed plant-based foods. The most obvious of these are grass seeds, especially after a lawn has been freshly seeded or overseeded. Birds like sparrows, finches, and pigeons are granivores and readily consume these seeds before they can germinate.
Weed seeds are also a common food source, consumed directly from seed heads or after they have fallen to the ground. Spilled birdseed from nearby feeders, such as sunflower or millet, becomes a highly concentrated food source that attracts ground-feeding species. This surface-level feeding is typically characterized by small, quick pecks rather than deep probing.
Assessing the Impact on Your Turf
The presence of birds foraging on your lawn presents a dual scenario for turf health. When birds consume grubs, crane fly larvae, and other insect pests, they provide a natural form of pest control. This predation benefits the grass by reducing root damage and mitigating the effects of an underlying infestation.
However, the physical process of hunting subsurface pests can cause visible damage to the turf. When searching for large grubs or earthworms, bigger birds like crows, magpies, and starlings may aggressively pull at the grass, lifting or tearing away patches of sod. This results in messy, torn-up areas, which are a sign of a high concentration of larvae just beneath the surface. Homeowners can distinguish between types of foraging by observing the damage: small, distinct holes suggest probing for individual pests, while large, ripped-up sections indicate active digging for a dense population of grubs. If the foraging is limited to quick pecks in areas with fresh seed or spilled feed, the impact is generally localized to the loss of those specific seeds.