Odd couple's bond threatened by love rival

They were brought together by a giant wave and it seems nothing can keep them apart. The unlikely couple of a baby hippo and a 130-year-old tortoise is still going strong - a year after the hippo was wrenched from his family by the Boxing Day tsunami.

Owen, the two-year-old hippopotamus, was found alone and dehydrated near Kenya's Indian Ocean coast after he became separated from his herd when the tsunami crashed into the shores of east Africa. He had been washed into the ocean and was stranded on a reef.

Rescuers in Malindi, a coastal town, used fishing nets to catch him and Owen was taken to the Haller Park sanctuary in Mombasa. The hippo was soon introduced to Mzee, an Aldabran tortoise whose grey colouring and rotund form was similar to an adult hippo.

But the relationship may soon come under threat when Mzee has to cope with a rival for Owen's affections, a 13-year-old hippo named Cleo who has survived 10 years without companionship from her species.

Mzee (which means old man in Swahili) initially resisted Owen's attentions, hissing and warning him to stay away. But after days of being followed around the park, into the pool and even into bed, Mzee relented and has since acted as Owen's surrogate father.

Park officials say the pair have been inseparable ever since. Pauline Kimoto, the park's tourism manager, said: "Since Owen arrived on 27 December, the tortoise behaves like a mother to him. The hippo follows the tortoise around and licks his face."

Conservation workers at Haller Park plan to introduce the female hippo early next year, hoping the two develop a strong bond which could result in reproduction. The delicate process will begin by getting the animals used to each other's smell before moving them into a larger enclosure - together, of course, with Mzee.