Kate Humble and Ben Fogle return to Longleat Safari Park. As temperatures continue to soar, so too does the number of new babies. Keepers are primed and ready to capture the first critical moments of life for a pair of rainbow lorikeets as they train 'nestcam' on a pair of eggs. Meanwhile, at Half-Mile Lake, another set of keepers are taken completely by surprise with the unexpected birth of a sea lion pup. Sadly there is not good news in every corner of the park. One of best-known giraffe in the herd has become very sick, and vets cannot get to the bottom of what is wrong with him. He is losing weight and looking frail - could this illness have spread to other animals, and could that threaten the future of the entire herd?