By Georgi B
The Bewick swans’ derrieres are being measured by the UK’s Wildfowl and Wetlands Trust to see if their fat reserves will last during their migration flight to Arctic Russia.
With the swans population in heavy decline, researchers at the trust have been investigating if the lack of appropriate food at the sites they reside in for the winter are to blame. They are currently gathering measurements before the swans set off on their annual journey. The area where fat is stored is between each of their legs and tail.
Julia Newth, a researcher at WTT told the BBC, “In a slim bird, the bum will look slightly concave, whereas a well-fed bird will have a double bulge”
The number of Bewick swans wintering in Europe dropped between 1995 and 2005 by around 9,000.The WTT believe the swans could be suffering from changes in their environment which could be a contributing factor to their survival.
Some breeds of swan are already facing extinction, the black swan (cygnus atratus) and the mute swan (cygnus olor) are both protected and four different types of swan are already completely extinct.