Distribution and abundance of the Pin-tailed Sandgrouse Pterocles alchata and the Black-bellied Sandgrouse Pterocles orientalis in Spain

Full article

Published:

Volume 45(1), June 1998. Pages 11-20.

Language:

Spanish

Original title:

Distribución y abundancia de la Ganga Ibérica Pterocles alchata y la Ganga Ortega Pterocles orientalis en España

Keywords:

abundance, conservation, distribution, Pterocles alchata, Pterocles orientalis, seasonal variation, Spain.

Abstract:

The Pin-tailed Sandgrouse and the Black-bellied Sandgrouse are endangered species in Europe, where their largest populations are in Spain. This paper defines their present Spanish distribution on the basis of both published and unpublished data. Their relative abundances of both species were estimated in 28 areas of peninsular Spain both in winter and spring by means of three 5 km walk transects per area. Abundance were expressed as the number of individuals per kilometre (IKA). The literature review shows that both species have disappeared or become rarified during the course of this century, especially in the margins of their distribution area. The Pin-tailed Sandgrouse may be currently considered as relatively abundant in the Ebro Valley, South Meseta and Extremadura, being quite rare in the North Meseta, Andalucía and Levante. Besides, it tends to concentrate in certain areas, reaching high abundances locally. As for the Black-bellied Sandgrouse, the most important populations are located in Extremadura and the South Meseta. This later species is present in a larger number of localities and has a more uniform distribution than the former but it is generally scarce. The winter and spring abundances of the Black-bellied Saundgrouse in the sampled localities where the species is present (n=23) were positively correlated. On the contrary, the abundance of the Pin-tailed Sandgrouse showed a more marked seasonal variation, so that no such correlation was found in the localities where it is present (n=14). There was no relationship between the abundance of these two sandgrouse species where they do coexist. This suggests that the factors influencing the habitat preferences of each species are species-specific.