After a 17-hour journey by highway, three bottlenose dolphins arrived at their new home in Harbin, Heilongjiang province on Monday morning.

It marked a new success in the transfer of dolphins during extremely cold weather in an extremely cold region, according to Harbin Polar Park.

This type of dolphin is usually found in temperate and tropical oceans. The ideal temperature for them is around 22 C.

The temperature in Harbin dropped to -29 C recently. The large temperature difference — around 50 C — brought great challenges to the transport operation.

To ensure the dolphins' safety, staff members from the park planned the route carefully and made contingency plan. They spent a month adjusting and testing various equipment and living conditions, including indoor temperature, water temperature and air quality.