From Wildlife Extra:
Bewick’s swans migrate but leave cygnet behind
February 2014: A Bewick’s swan cygnet appears to have abandoned by his parents at WWT Slimbridge Wetland Centre in Gloucestershire. Yesterday WWT researcher Julia Newth, who recognises the hundreds of swans in the flock by their individual face markings, saw that one family had acquired an additional youngster.
The lone cygnet has latched onto Slimbridge regulars Wooton and Stinchcombe and their four cygnets, but is spending much of its time calling in the hope of being reunited with its own parents.
Bewick’s swans migrate in large family groups and due to recent mild weather all but 10 of the Slimbridge flock have departed already.
Julia Newth said: “Occasionally, cygnets become separated from their parents during migration when there is perhaps bad weather, but it is rather more unusual to see such a separation before the journey has begun.
“We’re all waiting to see whether the parents return. If they don’t, and the cygnet leaves with its adopted family, we will call on our extensive network of swan researchers along the 2,500 mile journey to Russia to keep an eye out for them and check whether the lone cygnet manages to stay with them.”
Away from Slimbridge, where the swans are uniquely recorded by their facial markings, the swans are tracked by coded plastic rings on their legs. The lone cygnet has not been ringed but its adopted parents, Wooton and Stinchcombe, have white leg rings with the codes BAU and BAS.
Along the 2,500 mile migration between Slimbridge and Arctic Russia, the swans rely heavily on a chain of wetland sites for opportunities to rest and feed.
The Bewick’s swan study at Slimbridge celebrated its 50th anniversary earlier this month. Its findings have opened up the social structure of Bewick’s swans’ lives, revealing their lifelong pairing and strong family bonds. The longest-running dynasty is known as the ‘gambling’ dynasty, after a young swan was ringed and named Casino in 1971. Over the years that she returned to WWT Slimbridge she brought back 32 cygnets, who in turn have brought back cygnets of their own. This winter, three generations of the family have stayed at WWT Slimbridge, bringing their own respective partners and families, making them one of the most dominant and successful dynasties in the flock.
The study has also revealed the occasional anomaly, such as in 2010 when a regular pair, Saruni and Sarindi, returned with different partners. It was only the second instance of a swan ‘divorce’ in the entire study of more than 4,000 pairs.
For more information on swans visit www.wwt.org.uk/swans.