Ecology...?

From Scientific American's 60-Second Science blog:

So there's a female blue duck (Hymenolanimus malacorhynchos) named Cherry who is suspected to be the last female of her species in England. In order to save the species from extinction there, biologists introduced a pair of males to her (named, cleverly, "Ben" and "Jerry"), hoping that one of them would mate with her and allow the propagation of the species:

The boy birds, Ben and Jerry, were introduced to Cherry, but to no avail. "Cherry showed some interest in him," [Paul Stevens, the warden at Arundel Wetland Center] told the newspaper, referring to Jerry. "She displayed typical mating behavior — she approached him and called to him, she even looked like she was nesting. We thought it was great and it was all going to happen, but nothing ever did."

Feathers flew, however, when Ben and Jerry were shacked up together. "To our surprise, the two males really took to each other and it was obvious that they really liked each other," Stevens said, adding: "Ben and Jerry do make a lovely couple."