Abstract The Cantabrian capercaillie Tetrao urogal- lus cantabricus, a subspecies of the western capercail- lie, is endemic to the Cantabrian Mountains of northwest Spain. The range is separated from its nearest neighbouring capercaillie population by a dis- tance of more than 300 km. High genetic differentia- tion compared to capercaillie elsewhere qualifies the subspecies as an Evolutionarily Significant Unit. An assessment according to the IUCN Red List categories and criteria showed that the subspecies qualifies as Endangered due to rapid population declines, small population size, and severely fragmented range. The implementation of a range-wide recovery plan is vital for the survival of this subspecies. Keywords Assessment Æ Conservation status Æ Cantabrian Mountains Æ Evolutionarily Significant Unit Æ IUCN Red List of Threatened Species Introduction The IUCN Red List of Threatened Species (Hilton- Taylor 2000; IUCN 2004) plays a major role in con- servation policy and practice. All bird species, but not subspecies, are regularly assessed for their conserva- tion status by the Species Survival Commission (SSC) of the World Conservation Union (IUCN), based on the IUCN Red List categories and criteria (IUCN 2001). Subspecies are omitted because of capacity limitations, although the IUCN Red List categories and criteria can be applied to subspecies as well (S. Buchart, BirdLife International, personal commu- nication) and, thus, provide valuable support for con- servation action for threatened subspecies. Despite its extended distribution in boreal Eurasia, the capercaillie Tetrao urogallus is of major conserva- tion concern in Western and Central Europe both at regional and national levels (Storch 2000, 2001). Re- cent phylogenetic studies indicate that the subspecies T. u. cantabricus (Castroviejo 1967, 1975), an endemic of the Cantabrian Mountains of northwest Spain, forms a clade different from other European capercaillie (Rodrı ´guez Mun ˜oz et al. 2006), qualifies to be consid- ered as an Evolutionarily Significant Unit (Moritz 1994, 2002), and therefore deserves international con- servation concern. In this paper, we use the IUCN Red List categories and criteria (IUCN 2001) to assess the conservation status of the Cantabrian capercaillie. Assigning a Communicated by F. Bairlein I. Storch (&) WPA/BirdLife/IUCN/SSC Grouse Specialist Group, Department of Wildlife Ecology and Management, University of Freiburg, 79085 Freiburg, Germany e-mail: ilse.storch@wildlife.uni-freiburg.de M. J. Ban ˜ uelos Æ J. R. Obeso Æ M. Quevedo Ecology Unit, Department of B.O.S., University of Oviedo, Campus del Cristo, 33071 Oviedo, Spain R. Rodrı ´guez-Mun ˜ oz Centre for Ecology and Conservation, University of Exeter in Cornwall, Tremough, Penryn TR10 9EZ, UK A. Ferna ´ ndez-Gil Estacio ´ n Biolo ´ gica de Don ˜ ana (CSIC), Ecology Unit, Department of B.O.S., University of Oviedo, Campus del Cristo, 33071 Oviedo, Spain J Ornithol (2006) 147:653–655 DOI 10.1007/s10336-006-0101-5 123 SHORT NOTE Subspecies Cantabrian capercaillie Tetrao urogallus cantabricus endangered according to IUCN criteria Ilse Storch Æ Marı´a Jose ´ Ban ˜ uelos Æ Alberto Ferna ´ ndez-Gil Æ Jose ´ Ramo ´ n Obeso Æ Mario Quevedo Æ Rolando Rodrı´guez-Mun ˜ oz Received: 10 March 2006 / Revised: 24 July 2006 / Accepted: 24 July 2006 / Published online: 25 August 2006 Ó Dt. Ornithologen-Gesellschaft e.V. 2006