A hostile environment and inconsistent weather may explain why some birds become better singers than others, and also likely have superior learning and mating skills, a study said.
The research is based on a large-scale study of mockingbirds in different habitats carried out by researchers at the National Evolutionary Synthesis Center (NESCent) in Durham, North Carolina, the Cornell University Lab of Ornithology, and McGill University.
"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.