Some Birds Eat Poison to Attract Mates

Are you willing to chow down on some poison just to get the girl? No? Then you're probably not a great bustard, a particularly large Eurasian bird that purposely eats poisonous beetles to prove to prospective mates how tough and healthy it is.

"Hey girl, you want to see how many poison bugs I can eat?" may seem like the mother of all bad pick up lines, but a study recently published in the journal PLOS ONE details how there's a very good reason for this reckless behavior.

According to a team of field researchers from Museo Nacional de Ciencias Naturales, of the Spanish National Research Council (CSIC) in Madrid, Spain, the great bustard Otis tarda may be consuming blister beetles (Meloidae) as a form of self medication.

These beetles contain cantharidin, a highly toxic compound that can be lethal to the birds in moderate doses. However, when consumed in small amounts, the poison kills parasites that invade the reproductive orifices of the birds and can become a troublesome sexually transmitted disease.

For this reason, both male and female bustards were seen eating the toxic beetles. However, the team also observed that males consume them in far greater quantity. While dangerous, this assures that they have exceptionally clean cloaca - the reproductive orifice.

During mating season, the cloaca, which is also used for defecating, is rigorously inspected by females who are looking out for parasites and searching for evidence that the male can eat a lot of these beetles without becoming ill - a sign of strength and fortitude.

The researchers even suspect that the unique white plumage of males may have developed to help make this inspection easier.

"Our results do not definitely prove, but certainly strongly suggest that... self-medication might have been overlooked as a sexually-selected mechanism enhancing male fitness," the researchers wrote.

For the bustards, this poison-cleaned cloaca inspection is one of the only actions performed prior to mating, without the strange dances or elaborate displays of color that characterize other avian mating rituals. Bustards, it seems, are not exactly birds with a strong sense for the romantic.