60秒科学:Finches Seek Out Sick Dining Companions（在线收听）

Finches Seek Out Sick Dining Companions
A study in the journal Biology Letters finds that male finches prefer dining next to a sick bird despite the risk of infection, probably because the lethargic companion is less likely to engage in food fights. Karen Hopkin reports

When you’re looking for a table in a crowded cafeteria, you probably give wide berth to the family that sounds like it’s sharing a big dish of whooping cough. Well, not if you’re a house finch, particularly a male. Because a study in the journal Biology Letters [by Karen M. Bouwman and Dana M. Hawley at Virginia Tech; see http://bit.ly/afHGw7] shows that male finches actually prefer feeding near males who are visibly ill.

Finches don’t get whooping cough. But they are susceptible to infection with something called Mycoplasma gallisepticum, a bug that leaves them lethargic and sporting a bad case of conjunctivitis, otherwise known as pinkeye. The disease is quite contagious and can be passed from one finch to another while dining beak-to-beak. All the more reason, you’d think, for healthy birds to avoid sitting next to someone with crusty red peepers. Yet male house finches, when given a choice, opt to break breadcrumbs with males who are obviously under the weather.

Why risk catching a nasty infection when all you really want to catch is a quick bite? Because males infected with Mycoplasma tend to be less aggressive. So eating with the infirm means you’re more likely to wind up with seed in your beak than a beak in your eye.