Owls in the night

Last night from down the hill into the ravine outside our window we heard what could only have been bird sounds, but from a thick thorax cavity. One was nearby, on this side of the lake, and it called out at a somewhat regular rhythm. And then, from across the lake, came an answering call.

A little poking around shows this to have been the typical call of a Great Horned Owl.

I don't remember owls being around when I was growing up. Maybe there are now no predators, letting populations rebuild, or maybe I was ignoring them back then.