Food: fishes. Sexes slightly unlike. Found by water.
Larger than a robin; bill narrow and high, rather long and curved downward; wings long; tail long, soft, and rounded; toes in pairs. (Ridgway.)
Insectivorous. Sexes alike. Found on trees.
Mostly larger than a robin, a few smaller; bill hooked; eyes directed forward and surrounded by radiating feathers; plumage soft and lax; feathers beside forehead often stand up like ear tufts; legs usually feathered; feet sometimes feathered. (Ridgway.)
Sexes alike. Flesh eaters. Usually nocturnal. Most species found in holes in trees or old buildings.
Much larger than a robin; bill hooked; eyes very small; triangular-shaped eye disk; tail emarginate; claws sharp and strong; very downy plumage. (Ridgway).
Food: mice and other small mammals. Sexes alike. Exclusively nocturnal. Found in barns and deserted buildings.