male birds rule the roost

Male birds rule the roost.

By and large there are one third more male birds out there than females, according to a new study by Paul Donald of the UK Royal Society for the Protection of Birds.

This is despite the fact that as many hatchlings of each sex born. So the researchers conclude that unlike humans, female birds must have shorter life expectancies than males.

The finding is bad news for conservation efforts, which often estimate the size of populations by counting the number of males – it seems threatened birds might be even more thin on the ground than previously thought.

Strikingly, the researchers also found that the sex ratio was even greater in threatened species.

New Scientist, 31 Aug 2007