Abstract

The Northern Shrike Lanius borealis is a potential vagrant to northern and western Europe, both from North America (nominate borealis) and from Siberia (L. b. sibiricus). Currently, there are a handful of accepted European records, including three supported by DNA. There have been several other European claims of Northern Shrikes, especially from Finland, in recent years. A detailed study by the Finnish Rarities Committee, based on examination of museum specimens, led to the development of a multi-character scoring system. This highlights clear differences between many Northern and Great Grey Shrikes L. excubitor. Because some vagrants have shown intermediate characters, and mitochondrial DNA contradicted a seemingly obvious morphological Northern Shrike in Sweden, the Finnish Rarities Committee has opted not to accept records of Northern Shrike without DNA evidence. Nonetheless, the scoring system described here is a step forward in our understanding of the identification of Northern Shrike in a vagrant context1.