Distribution of the european turtle dove (Streptopelia turtur) at the edge of the South-Western Palaearctic: transboundary differences and conservation prospects

Abstract

The European turtle dove (Streptopelia turtur) is classified as vulnerable by the IUCN. In this context, it is important to explore the factors affecting its abundance and the ways in which it can be effectively managed for conservation. This study compares the distribution of this dove in Spain and Morocco. These countries, which are separated by the Strait of Gibraltar, are each occupied by a different subspecies (i.e. Streptopelia turtur turtur in Spain and S. t. arenicola in Morocco) that may be adapted to different environmental conditions. Such differentiation could result in differences in the species’ abundance between the two countries. The occurrence of this dove was assessed by means of road counts, and the resulting records were used to explore the niche overlap between the two subspecies. The niches of both populations overlapped, suggesting the selection of similar environmental conditions in the two countries. However, the species occurred more frequently in Morocco than in Spain. To study the potential role of local effects on the observed differences in abundance, 494 sampling points were surveyed in four different sectors of Spain and Morocco. These additional counts indicated that, after controlling for the effect of local habitat structure and climate, the European turtle dove is more frequent in Morocco than in Spain. Differences between the two countries, in relation to hunting pressure, agricultural intensification and the abandonment of marginal cultures and woodlands, could account for the observed transboundary differences in the abundance of European turtle dove and help to explain its severe decline in Spain.