'Northern' Treecreeper Certhia familiaris familiaris
The nominate familiaris of Scandinavian and eastern European form is a vagrant.
'Northern' Treecreeper: left Crook Bank, Saltfleetby-Theddlethorpe NNR October 14th 2013 and right, same site, October 15th 2016.
Centre photograph is of the British race britannica shown for comparison (all photographs courtesy of Alan Lowe).
Records of the nominate race are exceptional. Lorand and Atkin (1989) report that one was shot at North Cotes on March 13th, 1947 (the worst winter of the twentieth century). However, it is considered there are no safe field criteria for separating the two races and birds thought to be nominate race are now described as “showing characters of C.f. familiaris” since precise identification criteria still need to be developed (Hudson et al 2016) and submitted records will be ‘held until taxonomy or identification criteria are resolved”. Recent records of birds trapped and photographed in the hand at Crook Bank, Saltfleetby-Theddlethorpe Dunes NNR on Oct 14th-15th, 2013, and October 15th, 2016 were retrospectively accepted by BBRC in their 2020 report (British Birds 114: 570-628).
Reference
Hudson, N. and the Rarities Committee (2016). Report on rare birds in Great Britain in 2015. British Birds 109: 566-631.
(Account as per new Birds of Lincolnshire (2021), included December 2022)