Grand-duc d'Amérique vs Grand-duc de Magellanie

The Great Horned Owl and Lesser Horned Owl are similar in appearance, but the Lesser Horned Owl is generally smaller and browner with a more finely barred underbelly. Vocalizations are the most diagnostic difference between these species.

Look for size differences first; the Lesser Horned Owl is smaller. Note the browner plumage and more finely barred underbelly of the Lesser Horned Owl. Listen for vocalizations, which are distinct between the two species.

The Lesser Horned Owl is smaller than the Great Horned Owl.

The Lesser Horned Owl is browner and has a more finely barred underbelly compared to the Great Horned Owl.

Vocalizations are the most diagnostic differences between these species, though specific calls are not detailed.