Stress has a lot of negative effects. It can cause anxiety and anger. It’s associated with everything from sleepless nights to drug dependence. But stress is not actually positive or negative. It is ...

Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Nature documentaries ripe with images of bouncing birds with crazy ...

This is a preview. Log in through your library . Abstract The division of labour in parental care between the two sexes varies between and within species. In birds, parents have been shown to invest ...