Although for many this past weekend stands out as “Super Bowl” weekend, for me it was a “Superb Owl” weekend. In addition to seeing three Snowy owls (Bubo scandiacus) on Duxbury Beach, I was also able to locate Long-eared owls in Lexington.
Long-eared owls (Asio otus) are known to roost in areas of dense foliage, so it made sense when I was told about a group of them roosting in a thick stand of pines at the Dunback Meadow property in Lexington. As a nocturnal bird, they spend the daytime resting. The owls’ mottled feathers camouflaged them nicely, but with patience we were able to locate four of them high in two adjacent pines. Although dense branches made viewing difficult, allowing only an occasional glimpse of their orange faces and long ear tufts, the real treat for me was on the ground – owl pellets.
Intact owl pellets.
Long-eared owls actually require a combination of habitats; not only do they need dense tall trees for nesting and roosting, but they also need nearby grasslands or meadows for hunting. Dunback Meadow has both. Once they have caught their prey, because they cannot chew their food, they swallow it whole. Indigestible material left in the gizzard, such as teeth, skulls, claws, and fur would be too dangerous to pass through the rest of the owl’s digestive tract, and are regurgitated in the form of tightly packed pellets. I was able to find 6 largely intact pellets, in addition to some smaller fragments, immediately under the trees the owls were roosting in. Once home, I was able to pick through the masses of fur to uncover a plethora of tiny animal bones. Armed with a great deal more knowledge about rodent anatomy than I have, biologists can collect these pellets and identify the bones within to decipher what the owls have been eating and learn more about their diets.
Collections of small bones from each of the 6 owl pellets.
Long-eared owls are known to eat mostly small mammals, including voles, many kinds of mice, shrews, and young rats or rabbits. This preference for small mammals was certainly evident in the many rodent skulls uncovered from these owl pellets. However, they can also eat small birds, moles, bats, chipmunks, squirrels, and snakes.