Free porn, three females - and still Casey the gorilla hasn't got a clue

By all accounts, Casey the gorilla should have no problems with the ladies. Reports suggest the three females in his cage are positively besotted with him. They flutter their gorilla eyelashes at the handsome 21-year-old and follow him around.

Casey, however, is not interested. So, frustrated by their failure to encourage him to do his bit to increase their population of primates, the curators at New Orleans's Audubon Zoo have been resorting to X-rated tactics - gorilla porn.

Zoo staff have put a television into Casey's den to show him some pretty spicy films - a video on gorilla reproductive behaviour, shot at Denver Zoo, and footage from an Atlanta TV station, which had to bin a sequence showing two gorillas getting amorous behind the show's blissfully unaware presenters. Deep Throat it may not be, but staff had hoped it might do something for Casey.

Sarah Burnette, a zoo spokeswoman, said: "Gorillas are so endangered, and they are not overwhelmingly easy to breed. The main point is to carry out careful breeding because the gene pool is limited. No one is taking gorillas from the wild any more - there are not that many left."

So far, though, Casey has not been aroused by the special treatment. The staff know he likes to watch TVwhile his cage is being cleaned, but the steamy gorilla action has yet to improve his lacklustre performance.

The problem may be that because he was raised in captivity, whatever tricks he may have learned from his keepers have not helped him when it comes to getting it on with his female admirers, Fanya, Binti and Praline, and luring them to go for a roll in the bamboo.

Staff say Casey may be confused by the signals the females give him. Rolling around in front of him counts as a gorilla come-on, but flashing a puffy face is like saying: "Not tonight, I've got a headache."

"He made the wrong pick once, moving for a puffy face and all three of the girls jumped on him," Marsha Fernandez, the zoo's primate curator, told the Times-Picayune newspaper. "The females seem very receptive and interested but he just doesn't know the dance."

Dan Maloney, the zoo's general curator, confirmed Casey's companions were not the problem. "The girls watch [the videos] too, but they don't seem to need it as much. Even if it's a bit of a long shot, we're going to try it."

He added: "Casey is still trying to work out what it means to be the troop leader here, but he takes the job seriously and the other gorillas like him. The only sense of urgency is the clock is ticking for the females."