Jaya weighed just over four pounds when he was born on Thursday

Sumatran orang-utan Gina needed an emergency caesarean after staff found the placenta was blocking her birth canal, preventing her baby being born.

Staff called consultant gynaecologist Neil McLachlan and consultant anaesthetist Gary Purcell Jones.

Mr McLachlan performed an emergency caesarean and Jaya was born weighing just over four pounds (1.86 kilos).

Gina is a very maternal animal Richard Johnston-Scott, Durrell Wildlife Trust

He is now in an incubator and his mother is recovering after her sixth, and most unusual, delivery.

The zoo hopes to reunite Gina, who is 42, with her son on Saturday.

Mr McLachlan said that after carrying out an ultrasound it became clear a caesarean was the only option.

He said: "The placenta appeared to be quite low and the head was very high and the heartbeat had moments of slowing down a little bit.

"We had to cut through the placenta because it was actually blocking the birth canal.

"Had Gina continued like this she would have started bleeding very heavily and placenta previa can be a fatal condition."

Richard Johnston-Scott, who is head of mammals at the Durrell Wildlife Trust, said Gina had strong maternal instincts.

He said: "It's important to try and get the baby back as quickly as possible, because there is the lactation side of things as well.

"Gina is a very maternal animal - this is her sixth baby - and providing she is well enough, I don't see any problem with her accepting the baby."

The baby's father is the group's dominant male Dagu, and it is the first successful mating for the pair.