Re: Asymmetrical owl ears

["Norton, Patrick" <Patrick.Norton@state.me.us>]

<How is this different than just tilting the head?>

Sitting on a branch with eyes facing forward, an owl's asymmetrical ears   
increase its directional sensitivity for sound in the vertical   
plane--i.e., the rustle of a mouse down among the leaves versus the   
rustle of leaves overhead. Non asymmetrical ears are best at determining   
direction in the horizontal plane. And in addition, tilting the head   
involves movement, perhaps a dead give away to the intended prey.