Red-throated Diver

Fairly common offshore passage migrant and winter visitor Aug-May with peaks in mid-winter. Rare inland and in summer.

 

Red-throated Divers: left, Covenham Reservoir March 2006 (Michael Tarrant) and centre, March 18th 2010 (Mark Johnson); right, Barton Pits November 30th 2019 (Graham Catley).

 

Henderson and Wilson (2015) provided a detailed summary and discussion of Red-throated Divers wintering off Lincolnshire over the period 1978-79 to 2014-15. The general trend was of an increase in the wintering population and they highlighted the value and limitations of shore-based sea watching for detailed assessment of such changes. The largest count by far in the entire period was 1,308 seen off Gibraltar Point on February 20th 1999 and the mean peak for the period 2006-7 to 2014-15 was around 250. Their analysis showed peak use of Lincolnshire waters in January-March. The Greater Wash Special Protection Area, which extends from Bridlington to Great Yarmouth covering all the North Sea inshore waters off Lincolnshire, holds over 8% of the 22,000 UK wintering population, second only to the outer Thames estuary. It is now known from satellite radio tracking that birds breeding as far east as the Ob River Delta in Arctic Russia winter off Lincolnshire following a cycle of movements through the Baltic and North Sea during the winter. Since 2015 the peak count was 506 off Crook Bank, Saltfleetby-Theddlethorpe NNR on January 21st, 2018. Red-throated Divers are particularly averse to marine windfarm developments and it is to be hoped that as these developments proceed, they will be sited so as to minimise displacement of divers from prime feeding habitat.

Reference

Henderson, A. and Wilson, K.M.(2015). Red-throated Divers Gavia stellata wintering off Lincolnshire. Lincolnshire Bird Report 2015: 197-203.