Swans late leaving Slimbridge
No sooner had the swans departed, they had returned! After groups were heard noisily flying away from Slimbridge on Thursday night and fewer birds were found in the area the following day, swan researcher Steve Heaven was very surprised to arrive to a ‘full house’ of 282 on Sunday morning! Perhaps the birds had decided that conditions were not perfect, perhaps they sensed that a change of weather was imminent, perhaps something had disturbed them on their flight. We have seen ‘reverse migrations’ before but they are usually caused by a sudden change in weather rather than a more gradual deterioration.
Most classically, we sometimes see swans start their spring migration by leaving the Netherlands and hurrying on to Germany, before returning when conditions in Germany worsen.
Although we now seem to be in the midst of gloomy weather, there have been some bright and clear days recently and swans from other wintering sites have taken the opportunity to start their migration. Between Saturday and Tuesday, swan spotters at ‘migration watch posts’ across Holland had the pleasure of seeing hundreds of swans arrive from the UK and continuing their journey eastwards. These birds will have mostly come from the Ouse Washes in Norfolk, the most important wintering site for the species in Northwest Europe.
It seems that some of the Slimbridge swans have finally decided to leave us. This morning we recorded 192 swans (including 40 cygnets) at Slimbridge. It is quite remarkable to have such a high number of Bewick’s still here – this is the highest count for this time of year since 1996 when 195 swans remained! With temperatures cooling and north-easterly winds blowing over the next few days, they are likely to stay with us for a while longer yet....
