Barn swallows are common, agile birds often seen gracefully navigating the skies near human-built structures. They are recognized for their aerial acrobatics and their habit of consuming insects. Their diet and hunting methods contribute to their widespread presence across various landscapes.
What Barn Swallows Eat
Barn swallows are insectivores, meaning their diet consists almost entirely of insects caught in flight. Flies make up a significant portion of their diet, including house flies, stable flies, and blow flies. Beyond flies, their diet encompasses a wide array of other flying insects like mosquitoes, beetles, wasps, ants, moths, aphids, and true bugs. They also consume grasshoppers, crickets, damselflies, dragonflies, and wild bees.
Insects account for approximately 99% to 99.8% of a barn swallow’s food intake. While their primary food source is airborne insects, barn swallows may occasionally ingest small pebbles or grit. These materials aid digestion and provide essential minerals, such as calcium, particularly during breeding seasons.
How Barn Swallows Catch Prey
Barn swallows are highly adapted for catching prey in mid-air, a method known as hawking. Their flight is fast and agile, reaching speeds up to 72 kilometers per hour (45 mph) while hunting. They are highly maneuverable, capable of rapid acceleration and deceleration through flapping and gliding.
These birds possess a wide gape, allowing them to efficiently scoop up insects in flight. They forage in open areas, often flying low over water bodies, agricultural fields, or pastures where insects are abundant. Barn swallows also follow large animals or farm machinery, catching insects disturbed by these activities.
Barn Swallows and Insect Control
Barn swallows play a beneficial role in natural insect control. They are effective at reducing populations of agricultural pests and common nuisance insects. Their diet includes mosquitoes, gnats, and flying termites, which are often considered bothersome.
A single barn swallow can consume an estimated 60 insects per hour, equating to approximately 850 insects per day. This rate contributes to a substantial reduction in insect populations, potentially removing 25,000 insects per month per bird. Their presence is valuable in agricultural settings, helping protect crops by preying on pests.
Barn swallows frequent areas with livestock, feeding on flies attracted to the animals, aiding in fly management strategies. As migratory birds, their seasonal presence contributes to the reduction of insect populations across different regions.
Barn swallows and their nests are protected by the Federal Migratory Bird Treaty Act. This highlights their ecological importance.