The bisexual penguin at the centre of a much-reported love triangle is gravely ill.

Harry, a Magellan penguin at San Francisco Zoo, made headlines in 2003 when he set up home with another male penguin to incubate an egg. He later left his partner for a female penguin.

Zoo officials told the San Francisco Examiner that he was suffering from a respiratory infection that can be fatal to birds.

Harry is being cared for by the female bird he left his partner Pepper for.

They split up this summer, with the break being featured in Time Magazine’s top ten break-ups of 2009.

Harry and Pepper lived a peaceful existence together until Linda, a recently-widowed female bird, befriended Harry.

However, Pepper became jealous and violent at her arrival and had to be separated from the other two.

Harry and Linda have been moved to a special pool while zookeepers keep an eye on his progress.

Harrison Edell, the zoo’s curator of birds, told the newspaper: “Linda’s just there for companionship. Penguins are such social animals and we don’t want Harry feeling more stressed from being alone in addition to the stress of being sick.”

He added that Harry was suffering from aspergillosis.

“It is a serious veterinary concern,” he said. “But his appetite this week is a lot better than it was last week, and he’s moving around better. It seems like he may be feeling a little better.”