Life
Colorful duck bills hint at sperm quality, plus dangerous jellies and throwback bees in this week’s news
By Science News
Antimicrobial semen
To find a mallard with superior bactericidal semen, look for the guy with the most colorful bill. Researchers investigating male finery in a range of species have suggested that ornaments may reveal useful information about a potential mate, such as the strength of his immune system. In a new twist, mallard semen itself, especially from some males, has shown the ability to trounce
E. coli
and other bacteria in lab tests. Female mallards do fancy a colorful bill, so evolution may have favored preferences that reduce the risk of sexually transmitted infections or of bacterially damaged sperm, researchers say in an upcoming