Cantabrian capercaillie

The Cantabrian capercaillie (Tetrao urogallus cantabricus) is a subspecies of the western capercaillie in the grouse family Tetraonidae. It is one of two subspecies found in Spain. The capercaillie is a large grouse, 80 to 115 cm (31 to 45 in) in length, with the female much smaller than the male. It has dark grey plumage with fine blackish vermiculation (wavelike pattern) around the head and neck. The breast is glossy greenish-black. It has a long, rounded tail, an ivory-white bill, and a scarlet crest. The subspecies once ranged the length of the Cantabrian Mountains from northern Portugal, through Galicia, Asturias and León, to Cantabria in northern Spain (IUCN Redbook 1979, p. 1). Its range has since contracted to the mountains in northwest Spain. It inhabits an area of 1,700 km2 (656 mi2), and is separated from the nearest neighbouring subspecies (T. u. aquitanicus) in the Pyrenees by a distance of more than 300 km (190 mi).:268 Capercaillies are able to digest conifer needles, and their typical habitat is often described as old coniferous forest. However, the Cantabrian subspecies is not as reliant as other Western capercaillies on pine forest, a type of habitat which is relatively scarce in the Cantabrian mountains. The Cantabrian capercaillie feeds in deciduous woodland, and occurs in mature beech forest and mixed forests of beech and oaks (at elevations ranging from 800 to 1,800 m (2,600 to 5,900 ft). The capercaillie also uses other microhabitat types such as broom, meadow and heath selectively throughout the year.:271 It feeds on beech buds, birch catkins, and holly leaves. It also feeds on bilberry, a common component of its diet (Rodriguez and Obeso 2000 as reported in.:398 Storch et al. (2006) estimates the population to be 627 birds, of which approximately 500 are adults, according to the most recent population data collected from 2000 through 2003.:654 Population estimates for species of grouse are commonly assessed by counting males that gather during the leks (traditional places where males assemble during the mating season and engage in competitive displays that attract females). Pollo et al. (2005):397 estimated a 60–70 percent decline in the number of male leks since 1981. This is equivalent to an average decline of 3 percent per year, or 22 percent over 8 years. There is also evidence of a 30-percent decline in lek occupancy in the northern watershed of the species’ range between 2000 and 2005.:654 Based on data collected between 2000 and 2003 by Pollo et al. (2005),:401 the distribution of Cantabrian capercaillie on the southern slope of the Cantabrian Mountains is fragmented into 13 small subpopulations: four in the western area and 9 in the eastern. Six subpopulations (5 in the eastern and 1 in the western) contained only one singing male, which indicates a very small subpopulation, since presence of singing males is a direct correlate to population numbers. The area occupied by Cantabrian capercaillie in 1981–1982 covered up to approximately 2,070 km2 (799 mi2) of the southern slope 972 km2 (375 mi2) in the west and 1,098 km2 (424 mi2) in the east). Between 2000 and 2003, the area of occupancy had declined to 693 km2 (268 mi2), specifically 413 km2 (159 mi2) in the west and 280 km2 (108 mi2) in the east. Thus, over a 22–year period, there was a 66-percent reduction in the areas occupied by this subspecies on the southern slope of the Cantabrian Mountains.:401