Assessing the distribution, habitat, and population size of the threatened Dupont's lark Chersophilus duponti in Morocco: lessons for conservation

Abstract

Dupont's lark Chersophilus duponti was categorized globally as Near Threatened on the IUCN Red List in 2005, largely because of reported declines in Spain and an estimated population of 2,000–3,000 breeding pairs in Morocco. However, the range and size of the species' North African populations were still unknown, despite being critical for assessment of the species' global conservation status. Here we report on the breeding distribution of Dupont's lark in Morocco, probably the largest population in its North African range, as well as on its preferred habitat, population density and size. Fieldwork and analysis of satellite images were combined to locate suitable habitat for the species, assess its presence (eliciting territorial calls by broadcasting the males’ songs and calls), and estimate densities using 83 km of linear censuses. Total number of birds located was 461 (305 from song playback and 156 from transects) across an extent of occurrence of c. 11,000 km2, comprising 2,067 km2 of suitable habitat and an effective area of occupancy of 1,645 km2. Mean density was 0.60 ± SD 0.52 birds per 10 ha and was highest in dense stands of Stipa tennacissima. Our estimate of Dupont's lark breeding population in Morocco is c. 15,400 singing males (lower and upper limits 11,220–20,167, respectively). Evidence of habitat loss and degradation was found in one of the main areas of the species' distribution in Morocco, although this does not seem to be a general pattern in the lark's Moroccan range. Further studies are required of the dynamics of suitable habitat for the species to prevent long-term consequences for the conservation of Dupont's lark and other bird species of the steppe.