The team faces serious problems when orang-utan Hsiao-Lan gives birth, but refuses to look after her newborn. Meanwhile, siamang gibbons Sam and Sasak sing a duet in the trees.

Woolly monkey Bueno undergoes an operation, and slamang gibbons Sam and Sasak return to the trees. Meanwhile, Lingga gives Kai a hostile welcome in the orang-utan nursery.

Alison and Jeremy rescue four marmosets in the West Midlands, Milo the woolly monkey attempts to follow in his father's footsteps and the new baby gibbon is named.

The staff bid a fond farewell to their oldest marmoset, Betty Boo. Meanwhile, new Orang-utan Kai tries to fit in with the nursery group.

Hunchbacked capuchin Tau needs an operation but there are concerns surrounding whether to anaesthetise him. Mother-to-be Hsiao-Lan shows off her figure.

Oshine the orang-utan is weighed to assess whether her diet has been working and the squirrel monkeys mourn the loss of their leader.

Orang-utan Hsiao-Lan rejects Gordon's advances and moves back to the nursery. Meanwhile, woolly monkey Diego undergoes a delicate operation, and Jestah keeps the Bachelor chimps in line.

The team needs to perform a pregnancy test on orang-utan Hsiao-Lan, but face a difficult task to make her cooperate. Meanwhile, capuchin Tau takes to the trees for the first time.

Alison heads to Liverpool to rescue a baby marmoset. Meanwhile, overweight Oshine takes charge, and Siamang Sam inspects his new mate.

Capuchin Diez requires emergency surgery, and the team prepares to welcome new siamang Sasak. Plus, Oshine shows her softer side to baby Silvestre.

A special edition featuring a project to build Monkey World's first foreign sanctuary for endangered primates, a rescue centre in Vietnam that aims to provide future protection for gibbons.

Chimps Kiki and Trudy become best friends, and orang-utan Oshine has a health check. Plus, the keepers hope nervous Mita will finally venture outside.

Baby Sylvestre meets his new mother Oshine, and a woolly monkey arrives at the reserve from Kentucky.

The stump-tailed macaques are given a paddling pool to play in, and capuchin monkey Tel takes his first steps outside. Plus, siamang gibbon Onion may need an operation.

Tel makes a friend, and there is trouble in the chimpanzee nursery when Brian steals Ash's jelly. Plus, an update on the progress of the orang-utan enclosure.

Capuchin monkey Tel proves a hit with the females, and Hanaya's chimpanzees are reunited after two months apart. Plus, an update on the baby orang-utans.

Rescued chimpanzee Kiki has a tough time when she meets troop leader Cherry, and Jeremy heads to Slovenia to rescue two unhappy pet monkeys.

Woolly monkey Koona is unwell, and baby Sylvester is introduced to the other orangutans.

Rescued chimp Kiki finally ventures into the big outdoors after eight years in a tiny cage, and Jeremy visits Spain to collect a baby orang-utan.

Everyone hopes orang-utan Oshin will make a good surrogate mother to a new arrival, and chimp Cathy has an operation.