Factors limiting surgery for essential hypertension: Heinbecker, P.: Ann. Surg. 126:535 (Oct.), 1947

Abstract

The Cream-coloured Courser Cursorius cursor is a poorly known species inhabiting arid environments of the Western Palaearctic. The easternmost main islands of the Canary archipelago (Fuerteventura and Lanzarote, North Atlantic Ocean, Spain) harbour a stable population. The species showed an intense habitat selection pattern in these islands. Its probability of occurrence was highest in locations of relatively flat terrain (maximum slope steepness <11%), below 197 m a.s.l., with scarce shrub cover less than 16%, and a rock cover less than 23%. Roads were the only human disturbance among those considered in the study (i.e., dirt tracks, urban developments, agriculture), having a clear negative effect on the occurrence of the Cream-coloured Courser. This paper highlights the importance of an issue deserving greater attention in future studies: fine-grained habitat features, which are not directly related to vegetation structure, but are relative to topographic and lithological traits, largely determine habitat selection of birds inhabiting arid environments.