A Large-scale Survey of Brown Hare Lepus Europaeus and Iberian Hare L. Granatensis Populations at the Limit of Their Ranges

Abstract

The historical ranges of the European brown hare Lepus europaeus and the Iberian hare L. granatensis meet in Aragon in northeastern Spain. We studied the relative abundances and the population trends of the two species in 60 localities (13 for the brown hare, 38 for the Iberian hare, and nine from the transition zone where both species are present) by spotlighting in winter during 1992-2002. We carried out a total of 1,407 counts covering 41,511 km. Both the Iberian (132.2 6 33.2 hares/100 km; range: 52-192) and the brown hare (106.7 6 26.8; range: 53-136) were more abundant in their respective zones than both species combined in the transition zone (90.9 6 50.5, range: 37-157). The highest Iberian hare abundances were recorded in the northern Iberian Mountains, an area with well-preserved cereal-dominated ecosystems and a less extreme cli- mate than in other parts of the study area. The Iberian hare had signifi- cant inter-annual differences both locally and generally, which was main- ly due to a peak in 1998, and this species showed a general positive trend during the study period, suggesting that Iberian hare numbers are in- creasing. Contrary to the marked declines reported from other European regions, the brown hare abundance indices obtained in the Spanish Pyr- enees during our study period remained stable.