Croupier’s grandparents Nijinsky and Caroline, were first recorded at Slimbridge in 1969 and the family are known affectionately as the ‘Gambling Dynasty.’ A heartbroken swan who flew into Britain alone six weeks ago after losing his mate during the 2,500 mile journey has finally been reunited with his partner.Wildlife experts at Slimbridge Wildfowl and Wetlands Trust feared the worst when 26-year-old Bewick’s swan Croupier arrived without Dealer, who is mother to his 29 cygnets.The pair have been together for 19 years and are part of a lineage of swans which can be traced back decades. Bewick’s swan numbers have plummeted in the past two decades and it was feared Dealer may have been shot or poisoned on her journey back from Russia. But on Monday the Trust in Gloucestershire announced that Dealer has finally arrived after going missing for six weeks.WWT’s swan expert Julia Newth said: “During the 19 years they were together, Croupier and Dealer reared and brought back to Slimbridge 29 cygnets.”The cygnets learned the 2,500 mile migration route when following their parents and we often see different generations of the same family on Swan Lake at the same time.”Few families have demonstrated these birds’ characteristic site fidelity and loyalties to each other and we hope to see them continue to winter at Slimbridge for many years to come.” Croupier in ‘Swan Lake’ at Slimbridge Although swans live a long life but they do not produce many young. Bewick’s swans lay around five eggs each year on the Arctic breeding grounds but usually only one or two cygnets make it to their wintering sites in Western Europe.Experts at Slimbridge have been carrying out research to find out why the swans have declined by 40 per cent in recent years. WWT’s swan research assistant Steve Heaven said: “Our long-term study of the Bewick’s swans at Slimbridge has shed light on their ecological needs, important for survival. This information is crucial for helping us to understand why the population has been struggling”. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.