The Screech Owl is a small nocturnal predator found across North America, represented by two primary species: the Eastern Screech Owl (Megascops asio) and the Western Screech Owl (Megascops kennicottii). These owls are highly adaptable, thriving in diverse environments ranging from dense forests to suburban parks and backyards. Their success in varied habitats is tied to a flexible and opportunistic feeding strategy, allowing them to capitalize on whatever prey is most abundant locally or seasonally. The screech owl’s diet is one of the most varied among North American owls, reflecting its ability to hunt a wide spectrum of creatures relative to its small size.
The Diverse Prey Menu
The diet of the screech owl is remarkably broad, encompassing almost anything that moves and is small enough to subdue. Invertebrates form a substantial part of their diet, particularly during warmer months when they are readily available. This category includes large insects like beetles, moths, grasshoppers, and katydids, alongside spiders, centipedes, and even aquatic species such as crayfish and earthworms.
Small mammals constitute another significant portion of their food intake, often becoming the bulk of the diet, especially in winter when insects are scarce. Common mammalian prey includes calorie-dense rodents such as deer mice, voles, shrews, and house mice, which provide the concentrated energy needed to survive colder periods. Studies have shown that mammals can make up over 40% of the prey remains found in some regions.
Screech owls also prey on smaller birds, sometimes catching songbirds on their roosts at night, with over 50 species documented as prey in one study. Reptiles and amphibians are also taken, including small snakes, lizards, and frogs. The sheer variety of their prey highlights the owl’s adaptability and willingness to exploit any accessible niche.
Hunting Strategy and Technique
The screech owl is a dedicated nocturnal hunter, primarily relying on a “sit-and-wait” or ambush style of predation, often starting its hunt during the dim light of dusk. The owl selects a low perch, typically only a few feet off the ground, where it watches and listens intently for movement below. This low perching height, sometimes averaging only five to seven feet, provides an unobstructed view and a short flight path for a rapid strike.
Once prey is detected, the owl silently swoops down to capture it with its powerful talons, seizing and subduing the meal. Silent flight is achieved through specialized, serrated edges on their primary feathers, which disrupt the airflow and muffle the sound of their wingbeats. The owl’s acute hearing, aided by asymmetrical ear openings in the Eastern Screech Owl, allows it to pinpoint the location of prey concealed beneath leaf litter or snow, even in total darkness. After feeding, the indigestible parts of the prey, such as bones, fur, and feathers, are compressed into a pellet and regurgitated.
Regional and Seasonal Diet Shifts
The screech owl’s opportunistic nature results in pronounced shifts in its diet, driven by the time of year and local geography. The summer diet is heavily dominated by invertebrates, which are numerous and easily captured during the warm breeding season. Insects may constitute more than half of the owl’s food items during this time, providing a readily available energy source for feeding young.
As temperatures drop and insects disappear, the owl’s diet transitions to a reliance on small mammals that remain active throughout the colder months. Winter feeding focuses on voles and mice, which offer a high-calorie reward for the effort of hunting them. Regional differences further refine the menu, with Western Screech Owls in coastal areas sometimes showing a higher frequency of aquatic prey like fish and crayfish, depending on local abundance. Migratory birds also introduce a temporary food source, particularly where songbirds gather during their spring and fall movements.