Fun with Science Club®


			My name is Long-tailed McTit of the clan McTit. Episode II. Carrie Straight 05.18.01 In cooperative breeding systems, helpers that lend a hand caring for the young are commonly closely related kin to the breeders. In small cooperatively breeding birds, known as long-tailed tits (Aegithalos caudatus), their helpers are closely related kin. One common question for scientists is how these animals tell who is kin and who is not. Four scientists from the United Kingdom wanted an answer to this question. Specifically, they wanted to know if a nestling bird raised in a foster nest would be treated like kin or non-kin by its foster brothers and sisters (siblings). Answering this question required taking birds out of their own nests and placing them in foster nests. The researchers waited until the birds grew up and observed how they reacted to one another. Each bird was given color bands (rings) on its legs so that they could be told apart. The parents did not appear to behave differently between the foster young and their real young. The following year the researchers located as many of the birds as they could and made observations of their behavior. When the young birds were ready for their first nesting attempts, the nesting pair did not treat their real siblings and foster siblings differently. This means that they probably can’t tell the difference between foster kin and real kin. These results imply that birds learn who their siblings are and consider individuals they knew in their home nests as kin.


			Hatchwell, B. J., D. J. Ross, M. K. Fowlie, and A. McGowan. 2001. Kin discrimination in cooperatively breeding long-tailed tits. Proceedings of the Royal Society of London. Biological Sciences Series 268: 885-890.