2010-01-25 07:51:26
Experts have told of their surprise after witnessing a rare "divorce" between a
pair of swans at a Gloucestershire wildfowl sanctuary.
The Bewick's swans have returned to winter at the Wildfowl and Wetlands Trust
centre at Slimbridge - but both have brought new partners.
It is only the second time in more than 40 years that a "separation" has been
recorded at the centre.
Staff have described the new couplings as "bizarre".
It is not unheard of for the birds, which usually mate for life, to find a new
mate but it tends to be because one of the pair has died, they said.
During the past four decades 4,000 pairs of Bewick's swans have been studied at
Slimbridge, with only one previous couple moving on to find new partners.
Normally loyal
First suspicions of the rare event were raised when male swan Sarindi turned up
in the annual migration from Arctic Russia without his partner of two years
Saruni and with a new female - newly-named Sarind - in tow.
The pair's arrival led conservationists to fear the worst for Saruni.
But shortly afterwards Saruni arrived at the wetlands site - also with a new
mate, Surune.
And after observing them, the experts discovered the old relationship had ended
and new ones had begun.
Failure to breed could be a possible reason, as they had been together for a
couple of years but had never brought back a cygnet
Julia Newth Wildlife health research officer
Julia Newth, wildlife health research officer at Slimbridge, said the situation
had taken staff by surprise.
She said swans tended to have "real loyalties to one another" and long
partnerships.
"As long as they are both still alive, they will try to stay together. If they
have a change of mate it is perhaps because of mortality, not necessarily
through choice," she said.
In this case, however, both swans and their new partners are now over-wintering
in close proximity on the lake at Slimbridge.
Ms Newth said the old pair had not acknowledged each other with any signs of
recognition or greeting - even though they are occupying the same part of the
small lake.
As for why they may have split, she said: "Failure to breed could be a possible
reason, as they had been together for a couple of years but had never brought
back a cygnet, but it is difficult to say for sure."
Bewick's swans are the smallest and rarest of the three species found in the UK
and each individual can be identified by their unique bill pattern.