Grey Wagtails Suffer from the Cold Weather?

Over the last 18 years we have ringed 988 Grey Wagtails. Since 2008 we have been colour ringing those caught on passage along the coast at Heysham. Up to this year we have had 18 recoveries with all being either colour ring sightings, or recapture by other ringers, no birds have been reported dead. These recoveries show that our birds winter mainly in the  Chesire/Merseyside/ Greater Manchester area with single birds reported  from Wiltshire, Staffordshire and Pembroke.

However  this March we have had two reports of dead birds. The first was in Shropshire on March 1st. It was reported as being in poor condition indicating cold  weather. It had been ringed as a juvenile on September 25th 2017 at Heysham and had moved 137 km. The other was killed by flying into a balcony window in Conwy North Wales on March 13th. One can only assume that this bird was searching for food in an unusual  habitat during cold weather. It had moved 99 km and had been ringed on September 14th 2016.

So far the only local report of a dead bird during the cold spell was a Blue Tit . However we have been fortunate with only a short lived  covering of snow.