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Range DescriptionChersophilus duponti has two subspecies: the nominate is found in Spain (mainly east Castilla y Leónand Aragón, also west Castilla y Leónnear Portugese border, east Castilla-La Mancha and south-east Andalucía), Morocco (mostly in north-east, east of Midelt and the river Moulouya, also recent records from south of Great Atlas) and north Algeria (Hauts Plateaux); margaritae is found in Algeria (south slopes of Atlas Mountains east to Biskra), south-east Tunisia, northern Libya and coastal west Egypt. It is sparsely distributed and uncommon in most areas of its relatively small and fragmented range. Currently in Europe, the species is only found in continental Spain, which hosts around 13% of the global population of the (Suárez et al. 2008). This Spanish population declined by more than 20% during 1970-1990 (Tucker and Heath 1994), but this rate of decline was thought to have slowed during 1990-2000 (BirdLife International 2004), with the total Spanish population estimated at 13,000-15,000 pairs following surveys in 1988 (Garza and Suárez 1990). However, the original survey may have dramatically overestimated the size of the Spanish population, which may have comprised as few as 1,900 pairs in 1988 (Garza et al. 2003). Based upon census data collected in 2004-2007, the population was accurately assessed as 3,500-4,200 singing males (Suárez and Garza 2007) with declines noted in most areas (Vicente et al. 2006). Taking into account that the sex ratio is approximately 0.61 (Suárez et al. 2009), these results would mean the existence of roughly 2,200-2,700 pairs. Some authors consider that the sex ratio is even more biased towards males (Tella et al., 2004; Vögeli et al., 2007) which would lead to an even smaller population estimate. In Morocco, the species has a scattered and uneven distribution, and is not recorded in large areas of apparently suitable habitat. Recent work in Morocco calculated the extent of occurrence at 11,000 km2 including an effective area of occupancy within suitable habitat of 1,645 km2 (García et al. in press). This area was estimated to support a population of 15,400 singing males (García et al. in press). The number of birds in eastern populations is not known, but it appears the global population numbers a minimum of 35,000 individuals and may be considerably higher than this. There is some evidence of a skewed sex ratio suggesting that the effective population size may be lower (Tella et al. 2004; Vögeli et al. 2007). As well as declines noted in Spain, habitat loss has been recorded within the Moroccan breeding range, but its impact and overall trends are not well understood. Further information on population size and trends from the remainder of its North African range is needed, and this may lead to the species's reclassification in the future.