YAWP

"In many birds, helpers delay their own reproduction to raise the young of others. Because the breeders are typically related to them, theory suggests that helping results from kin selection. But other theories hold that helping could be driven by reciprocal altruism. Both mechanisms are true, as shown by a study of superb starlings in Kenya, illustrating the importance of long-term field studies, and the difficulties of fitting theory to the real world."

— Henry Gee, Senior Editor, Nature

"In many birds, helpers delay their own reproduction to raise the young of others. Because the breeders are typically related to them, theory suggests that helping results from kin selection. But other theories hold that helping could be driven by reciprocal altruism. Both mechanisms are true, as shown by a study of superb starlings in Kenya, illustrating the importance of long-term field studies, and the difficulties of fitting theory to the real world."

— Henry Gee, Senior Editor, Nature

https://www.nytimes.com/2025/05/07/science/birds-friendships-superb-starlings.html