A new study has divided some species of bird into groups of more and less
aggressive males. Researchers test the response of male collared flycatchers
to female birds, to a strange object, and to other males. They found that each
type of individual displayed consistent behavour in each of these situations.
However, they also found that the birds more likely to take risks also were the
ones most likely to be trapped and this prooves that raising important
questions about the skewed sample set presented when researchers based
their findings on animals caught in traps.