The race of Redwing (T. i. coburni) breeding in Iceland and the Faroe Islands averages slightly larger and darker brown than the nominate race which breed across Scandinavia to Siberia and wintering in Europe, Africa and Asia. Iceland birds winter from western Scotland and Ireland south to northern Spain where they may mix with nominate T. i. iliacus. Iceland birds differ in by their more extensive ventral streaking which tends to form broad solid lines rather than discrete streaks. This species is sometimes known as "Red-winged Thrush" which has the advantage of avoiding confusion with the unrelated Red-winged Blackbird of North America, also sometimes called "Redwing." Although locally common, this species has been listed as "Near Threatened" by IUCN based on estimated population declines of 30% over the last three generations. Canon SX50 HS PowerShot.
References:
BirdLife International. 2017. Turdus iliacus (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2017: e.T22708819A110990927. http://dx.doi.org/10.2305/IUCN.UK.2017-1.RLTS.T22708819A110990927.en. Downloaded on 09 September 2018.
Clement, P. & Hathway, R. (2000) Thrushes. Princeton Univ. Press, Princeton.
Collar, N., de Juana, E. & Sharpe, C.J. (2018). Redwing (Turdus iliacus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/58254 on 9 September 2018).
Voelker, G., Rohwer, S., Bowie, R. C. K., Outlaw, D. C. (2007). Molecular systematics of a speciose, cosmopolitan songbird genus: defining the limits of and relationships among the Turdus thrushes. Mol Phylogenet Evol. 42: 422-434.