The Long-eared Owl ( Asio otus) is a crow-sized owl (15 inches) with long ear tufts close together and a wingspan of 39 inches. The color is heavily mottled brown with chestnut facial disks. Although these woodland owls are gregarious in winter, they are so nocturnal and quiet that up to a dozen may inhabit a dense evergreen grove without being detected during the day. The voice is soft low hoots, also whistles, whines, shrieks, and cat-like meows. It is seldom heard except during breeding time.
Long-eared owls tend to roost near the trunk of a tree, and since they elongate themselves by compressing their feathers, they resemble part of the trunk itself. Only by peering intently upward can one detect the round face and telltale long ear tufts. In flight, the long-eared owls ear tufts are nearly invisible.
When the owl has perched and is attempting to blend in, its ear tufts are erect. These tufts can sometimes confuse observers into thinking that they are looking at a Great Horned Owl. The long-eared owl’s slender appearance and smaller size should resolve the problem.
Mortality of long‐eared owl fledglings is very high, due predominantly to starvation and predation by mammals or birds. The first owl in a brood disperses and gain independence about 50 days after fledging, the last one approximately 80 days. Before independence, the main cause of death is usually predation; after independence, starvation.
The overall mortality of first‐year owlets is much higher than previously suspected. Before independence, young owls face a specific trade‐off: loud begging calls secure them more food from parents, and thus, a higher probability of survival, but it also increases predation risk.
A good way to locate an owl roost is to search in pine woods for groups of pellets. They tend to be more strictly nocturnal than barn owls. The best places to find long-eared owls are areas that have not been plowed for at least three years. Regular plowing eliminates small animals these owls prey upon. Your best bets would be prairies, marshes and old fields.