Great Horned Owl

The Great Horned Owl is the largest breeding owl in New Hampshire (the Snowy Owl is heavier), but far less common than the smaller Barred Owl. It is a species of forest edges and open forests and thus absent from many of the heavily wooded parts of the state. The best places to find them are near fields, orchards, and large wetlands. With home ranges sometimes exceeding 100 acres, they can cover a lot of territory and are often not detected even if they are known to be present. By far the best way to find a Great Horned Owl is to listen for their deep hoots at dawn and dusk. If you hear a pair calling back and forth, the smaller male is the higher-pitched call compared to the larger deep-voiced female.

This calling intensifies in late fall, when Great Horned Owls are starting to prepare for nesting. In the northern United States, they may lay eggs by late January or early February, which the female will incubate for a month. It’s thus possible to have young owls in the nest by late February. The nest itself is usually either a snag or an existing nest commandeered from another large bird like a hawk or heron. Because these owls nest so early, you can sometimes find nests by looking for incubating birds in large stick nests well before the leaves come out. After hatching, the owlets remain in the nest for over a month, but still aren’t adept flyers for at least another month.

Great Horned Owls are one of the most impressive avian predators we have in New Hampshire, sometimes taking mammalian prey as large as skunks and cats (another good reason to keep cats indoors!). They hunt almost entirely at night, and thus have a smaller proportion of non-mammals in their diet than other owls. When they hunt eat birds, they tend to focus on larger species such as ducks and other waterbirds, usually taking them from nests rather than the water. They will also take young birds from the nests of crows and hawks, and even eat other owls. The latter is why birders looking for owls generally don’t start by imitating this species; doing so is likely to keep the smaller species quiet.