As part of the behind-the-scenes panda experience, a private guide shuttles guests around the rest of the 260-acre preserve, which also houses red pandas, golden monkeys, cranes and other rare birds.

BBC: Play one-on-one with a giant panda

But it said persistent bad weather and low temperatures meant only half survived, while other rare birds including goshawks have also struggled.

BBC: Cold weather kills three Kielder osprey chicks

The corpses of several rare birds, along with poisoned bait and other evidence, were removed.

ECONOMIST: Technology to the rescue