There's chaos at the capuchin house when Winslow's group have a weigh-in. Meanwhile, there's dissent in the ranks when chimp Tikko appears to challenge Hananya for leadership.
Five-year-old Jin leaves home and joins the Orang-utan nursery. Meanwhile, troublemaker chimp Bart is up to his usual mischief when Paddy's group are given sacks full of treats.
Chimp Tikko goes under the knife when he gets a tooth infection, newcomer Floh meets leader Sam and golden-cheeked gibbon Tien is on the look-out for a mate.
Alison agrees to take in a neglected marmoset. Baby Leo is brought to the park by the RSPCA and is in a dreadful state, leaving Alison unsure as to whether he'll survive.
Golden-cheeked gibbon Tien finally meets his new mate, Kim. But the course of true love doesn't run smoothly. Meanwhile, naughty chimp Rodders pushes Lulu to the limit.
There's great excitement at Hananya's enclosure when chimp Cherri finally gives birth to twin baby girls. Elsewhere, woolly monkey Pacaja takes a shine to leader Oaska.
It's the day of the great ape move as Gordon's orangs swap houses with Sally's chimps. But it's a mammoth operation involving the veterinary team and the primate care staff.
It's all change for Lulu, Rodders, Ash, Brian and Sally, who now have other chimps living nearby. Meanwhile, baby marmoset Leo is finally well enough to meet his new housemates.
Hananya's chimps are subdued when Cherri loses one of her newborn twins. Elsewhere, a fight breaks out at the lemur enclosure when two new arrivals are given a rough welcome.
Alison heads to Cheshire to rescue four more marmosets. Meanwhile, the primate care staff build a special enclosure to keep baby woolly monkey Bueno Junior safe.
At the orang nursery all eyes are on Hsiao-quai to see if she will step up to the mark and adopt baby Bulu, who has just arrived from Hungary after losing his mum.
There's sad news at Paddy's enclosure when the team are forced to make a tough decision about chimp Susie, who is suffering from an inoperable heart condition.
There's exciting news for baby orang-utan Bulu as six-week-old Rieke is due to join him from Berlin Zoo. Meanwhile, the new marmoset house is finally set to open.
Baby orang-utan Rieke arrives from Germany and immediately hits it off with new playmate Bulu. At the park's hospital, chimp Jestah undergoes a major tooth operation.
Baby orang-utans Bulu and Rieke are running the team ragged. They need around the clock care and are proving to be quite a handful. Meanwhile, chimp Hananya lets his hair down.