Tytonidae Barn-Owls

The well-known Barn Owl serves as strong contrast to the ten or so similar species that are very little known: most of these occur in limited ranges on various tropical islands, and for eight the breeding biology is essentially unknown. The lighter build and longer legs of tytonids, compared to strigids, seems to suit them better to warmer climes. All of these birds share a heart-shaped facial disk, which collects sound waves, and, as in some strigids, asymmetrical ear openings, adaptations for night hunting. Their calls, often given in flight, are more hiss or scream than hoot. Everywhere, they apparently subsist on large numbers of small rodents, and the Barn Owl has a remarkable capacity to adjust its reproductive output to variation in its food supply.