A BABY hippo that made a splash when he was born unannounced a year ago is about to give zoo staff a different sort of headache.

Zippo the hippo was born at Flamingo Land, near Malton, in North Yorkshire, in August last year. Staff did not know that his mother, Betty, was pregnant because she had arrived at the zoo four months earlier.

However, to stop the two from being separated, Betty will need to be put on contraceptives soon to prevent the pair from breeding.

Zoo staff said they could either have had Zippo rehomed or put Betty on the pill when Zippo becomes sexually mature in a few years.

Melanie Wood, from Flamingo Land, said: "The last thing we want to do is separate mother and son. This seems the kindest thing to stop them breeding.

"Contraception is becoming more and more common amongst all species and we have done it to our monkeys in the past. It is easier than to separate them and make them celibate."

Another female hippo, who is no relation to Betty or Zippo, will also be given the pill to stop the zoo's hippo population from growing. Mrs Wood said: "At the moment we have got it just right, with two girls and a boy, and they are all living harmoniously."

Zippo has just celebrated his first birthday, but will not be fully grown until he is about six.

Mrs Wood said: "Even now, it is clear that he is still a baby because he is much smaller than the other two.

"The three of them have got a mud bath and they wallow in it from morning until night. They are an enormous crowd-puller, especially among the children."

The hippos live in new quarters in the zoo's Lost Kingdom -a ten-acre area that also houses rhinos and giraffes.