Here's a bird song we all recognize, the familiar crowing of, yes, crows, a species with many vocalizations. Crows are one of the most intelligent animals in the wild, and a lot of intelligent people have come up with theories to explain why.
For one, crows are highly social, constantly having to figure out complex group dynamics. Seldom if ever will you see just one or two. Unlike most wild animals, crows mate for life. Equally unusual, the young of one year stick around to help raise the next generation. This apprentice system, as young learn from their elders, is thought to boost their intelligence. Social within the family group, crows also join up in large overnight roosts in the winter.
Another theory for crow intelligence has to do with diet. Crows learn to eat just about everything, and this ability to recognize a variety of foods requires definite brain power. They also cache food for future consumption, and are capable of remembering numerous hiding places.
As a species, crows have adapted well to a changing landscape as forests were cleared for farm and town. In fact, they likely moved to town and city to escape the country man's shotgun back in the days when crow-shooting was legal year-round. Crows, once aggressively persecuted, have handed a wariness down to present generations—another sign of intelligence. Their wariness makes them a difficult subject for ornithologists to study.
Crows stand out now, black against November's barren, transparent landscape. Listen, and you'll hear a language as complex as their social interactions. While other birds quiet down in the nonbreeding season, the crow keeps talking.