Mockingbirds Sing Better in Harsher Climates

Northern Mockingbird / Photo by Ryan Hagerty (USFWS)

Earlier this week, we learned of one aspect of mockingbirds' cognition, the ability to distinguish among individual humans. Another study released later in the week found that male mockingbirds in more variable climates tend to become better singers. The study used over 100 tracks from 29 mockingbird species as a basis for comparison.

"As environments become more variable or unpredictable, song displays become more elaborate," said Carlos Botero, a postdoctoral researcher at NESCent.

"Survival and reproduction become more complicated when weather patterns are unpredictable because you don't know when food will be available or how long it will be around."

And for female birds, "the consequences of picking a mediocre mate are magnified in harsher climes," he said.

Male mockingbirds sing mainly to impress mates, so superior singing skills suggest that a male is a good catch, according to Botero. But males that sing more complex songs also "tend to carry fewer parasites, and have offspring that are more likely to survive," Botero said.

Songbirds are not born knowing how to sing, and have to learn their songs over time. Botero and colleagues believe that this song-learning ability is a sign of broader learning ability.

Abstract and article available here.

My one complaint is that the AFP article does not specify what it means for a mockingbird song to be "better," or how the scientists measured quality. One could potentially look at different aspects of a song; its clarity, pitch accuracy, volume, and complexity could all legitimate bases for comparison. Since the discussion focuses on a bird's learning abilities, my guess is that the scientists were looking for complexity. Since mockingbirds learn not only from other males, but also sounds in their environment, song complexity probably is a good proxy for cognitive abilities. Still, I would have liked this aspect to be a bit more clear.