Kate Humble and Ben Fogle are back for another sunny summer series following the remarkable lives of the exotic animals at Longleat Safari Park, and the keepers who care for their every need.

The keepers recently discovered that the mother of the wolf pack, Eliska, is pregnant. However, in today's episode, their joy turns to fear. They've spotted some very strange behaviour. Eliska is lethargic and not interested in her food. She's clearly in need of urgent attention, so the vets are called, but if the worst happens, what will be the implications for the rest of the pack?

This summer, we have been following the first southern koala joey born in Europe, tracking her progress day and night as she has grown before our eyes. Today, Kate and Ben meet her to find out what she's eating, how fast she's growing and if mum and daughter are bonding.

Megan McCubbin continues to discover how the team keep their animals entertained and in great condition, and as a former animal keeper herself, Megan needs no encouragement to get stuck in. Today, she's planting a lawn of grass for the southern hairy-nose wombat, and she reveals why they have cube-shaped poo. Meanwhile, wildlife cameraman Hamza Yassin uses his powerful macro lens to film the park's spiders in extraordinary detail.

Kate Humble and Ben Fogle return to Longleat Safari Park for another spectacular summer series following the fascinating stories of the exotic animals and the keepers who look after them.

Today, the team are braced for the arrival of a species that hasn't lived at the park for 30 years. Longleat is already home to a collection of eleven wallabies, but the park's visitors often confuse them with kangaroos, which are much larger. The best way to teach them the difference is for the two species to live side by side, so a kangaroo is making the 400-mile journey from Edinburgh Zoo to join the collection in Wiltshire. But keeper Gemma is worried. She has looked after wallabies for years and knows they can be quite tricky to control, but kangaroos can grow to more than double the size and are capable of jumping eight metres. Just how big is the animal that she will have to look after?

Elsewhere, another new arrival is causing a stir. The native Eurasian beaver has returned to the estate for the first time in 400 years. This isn't just good news for the park but also for the environment. Beavers are nature's ultimate engineers, and their dam building encourages other species to take up residence. In an astonishing development, the Beaver Trust has been called in because some footage exists that might prove that the beavers have had babies.

Zoologist Megan McCubbin feeds the only Californian sea lions in the world who share their home with hippos, and she finds out if, after a traumatic summer, the wolves will unite for a morning howl. Meanwhile, wildlife cameraman Hamza Yassin may have met his match when he is set a photography challenge by Animal Park legend Ian Turner.