Several years ago I went flyfishing in Lake Almanor for smallmouth bass. As I rowed toward the dam in my pontoon boat I noticed there was a lot of noise and activity at the dam. Swallows were circling the cylindrical dam in large numbers and there were crows flying through the swallows toward the dam’s face. I rowed closer to see what was going on. The crows were flying into the side of the dam feet first. As I got closer I saw what was happening. The crows were crashing into the mud nests of the swallows and grabbing the chicks from the smashed nests. The swallows were powerless to stop it. I’m pretty sure the crows destroyed all the nests and got all the young. It was one of those moments in nature when my emotions really get aroused. I know the crows need to eat, but I still felt sorry for the swallows. I wondered if the swallows would nest there again or find some other place. I never went back to find out.
Fast forward several years. I got a tip that there was a great horned owl nest on a ledge of an old building near my house. I went there and sure enough there was a nest. I was told that a pair of owls has been nesting there for years. Here is a photo of one of the adults and the three young on the nest.
I photographed the owls at the nest for nearly a month. I don’t remember now how long it took me to realize that there were many swallow nests near the owl nest because I was pretty absorbed by the owl family. It was probably when the swallow chicks had hatched and the parents were frequently flying to and from the nests feeding their young. Here’s a photo of some swallows and their nests immediately under the owl nest.
Anyway, at some point a light bulb went on in my head. Great horned owls eat crows. They love them. What I have wondered since then is whether the swallows were smart enough to build their mud nests near the great horned owl nest because they thought building them there would protect their nests from crows or was it just a coincidence? I don’t know, but I like to think they are intelligent enough to nest there for their own safety’s sake. There were no attempts by any crows to attack the nests. This crow was the only one I saw that came anywhere near the swallow nests. He’s about 25 yards from the nests.