England now has the largest polar bear centre anywhere in the world outside of Canada, following the arrival of three cubs and their mother at a park in Doncaster.
They join four male polar bears already living at the Yorkshire Wildlife Park (YWP), which has been dubbed the polar bear capital of Europe.
The 18-month-olds are triplets, which are rare for polar bears, and are settling into a new enclosure with their mother, Flocke, aged 12.
Dr Macdonald also said the cubs have adapted well and are enjoying their new home.
“One of the cubs has just been exploring the climbing frames, going up high off the ground, and they’ve been playing in the water a lot.
“The cubs are very, very curious, and I can see that they will get into mischief in the future,” she added.
The family consists of Flocke; two boys, Indiana and Yuma, who are already catching up to their mother in size; and their smaller sister, Tala.
Dr Macdonald said the new additions make the park, on the outskirts of Doncaster, the second biggest polar bear centre in the world with the only one bigger located in Canada.
She said the park provides an excellent environment for its bears, complete with the large areas of land and deep water needed by the largest land carnivore.
Project Polar 1, which is home to the original four bears, is a 10-acre reserve with several lakes, and she said that in the new Project Polar 2 the bear family enjoy a similarly spacious enclosure with cool water for when the cubs fancy a dip.
YWPF trustee Cheryl Williams said: “Working together with YWP, the Yorkshire Wildlife Park Foundation will continue to work to conserve polar bears and inspire people to care about them and the Arctic.
“Let’s hope that seeing Flocke and her youngsters at YWP inspires people to support bears in the wild, who face so many challenges, and raise awareness to effect change in governments for action for climate change.”
The bears are currently finishing their quarantine and it is expected that visitors will be able to meet them from later this week.
