Keep Your Hens Happy

Posted by on October 24, 2005 in Chickens | Comments Off on Keep Your Hens Happy

This just in from Clarence Court. I’ll have a great deal more to say about them soon. Thanks to Small Farms for sending me to them.

Possessive cockerels use fake sex to keep their hens faithful. By merely mounting females – without bothering to waste precious sperm – cocks ensure their partners will not go looking for male competitors to fertilise them, a new study suggests. The finding may explain why males of many species – from insects to mammals – engage in seemingly meaningless sperm-free sex.

“Copulations that appear to be successful, but with no semen transferred, are almost ubiquitous,” says Tommaso Pizzari at the University of Oxford, UK, co-author of the study. “It suggests that this behaviour may be rather more than an accident or a by-product of males running out of sperm.”

While sperm was always thought of as a cheaper investment than eggs, in the past few years, researchers have begun to realise that sperm also carries a hefty biological price tag. In 2003, Pizzari and his colleagues showed that male chickens allocated their precious seed according to the likelihood of fathering children. Unfamiliar females always received a fulsome dose, while hens with which the cock had already mated several times ended up receiving little more than ruffled feathers.

Journal reference: Current Biology (vol 15 p 1222)