An endangered polar bear who was sent to another zoo immediately after his birth has returned after spending 15 years abroad.

The 15-year-old polar bear reunited with other bears at the Schoenbrunn Zoo, in the city of Vienna, Austria, after spending 15 years at the Nuremberg Zoo, in Germany.

Head of the zoological department at Schoenbrunn Zoo Folko Balfanz said in a statement on Monday May 8: 'It's actually a happy reunion.

'The polar bear male was born here in Schoenbrunn in 2007.'

Balfanz said that there are currently two polar bear males at the zoo, which live in separate enclosures, each equipped with a water basin.

The transfer - which is a part of the European Endangered Species Programmes (EEP) - included the relocation of a female bear born at the Vienna Zoo in 2019, to the German zoo.

Schoenbrunn Zoo director Stephan Hering-Hagenbeck emphasised that breeding of polar bears at the zoo is currently prohibited.

He said: 'The aim of the conservation breeding program is to ensure that the genetic diversity of the respective animal species in human care is as large as possible and that we build up a healthy reserve population.

'It is the job of the studbook keeper to keep an eye on the population over many years and to plan the exchange of animals within the participating zoos.

'At present, some males of the solitary polar bear are not needed.

'Therefore, the number of breeding recommendations has been reduced.

'Schoenbrunn Zoo is able to temporarily support the studbook in its two enclosures in the current situation by providing adequate space.'

Polar bears (Ursus maritimus) are listed as 'vulnerable' on IUCN's Red List of Threatened Species.

Despite their current population trend being unknown, global figures indicate that between 22,000 and 31,000 individuals live on the planet as of 2015.

Officials from the Vienna Zoo added: 'Schoenbrunn Zoo has been supporting the organization Polar Bears International in various projects for many years, such as tagging wild polar bears to research their migration routes.

'This year, too, the zoo is co-financing the GPS transmitter of a female named 'Arctic Ambassador'.

'The polar bears in Schoenbrunn will soon be testing newly developed smaller transmitters for use in the wild.'