Association of a threatened forest ungulate with the treeless herriza or Mediterranean heathland in southern Spain

The Andalusian roe deer (Capreolus capreolus var. garganta) is a medium-sized ungulate species whose unique biological features and protected, red-listed status have made it a highly prized hunting trophy. This game species is relatively abundant in forest ecosystems of southern Spain (province of Cadiz), at the European side of the Strait of Gibraltar. In this region, the herriza or Mediterranean heathland is a relatively abundant natural habitat of outstanding biodiversity value but frequently underappreciated due to its characteristic treeless feature. We searched available abundance data of roe deer in 182 hunting estates in the province of Cadiz during three four-year periods (2006-2009, 2010-2013, and 2014-2017) and obtained surface cover data of herriza habitat for each estate. We also collected data on other variables that could influence roe deer abundance, such as hunting estate surface area, and relative abundance of red deer (Cervus elaphus), a co-occurring game species. Then, using a spatially explicit approach, we explored the association of the Andalusian roe deer with the relative abundance of herriza and red deer in the hunting states. A significant, positive effect of the relative abundance of herriza in the hunting estates was found for the Andalusian roe deer abundance but not for the red deer. Although reasons for such positive association remain speculative, an ecosystem service potential of the herriza should be considered, not only to enhance the conservation of a protected, singular game species, but also to promote the conservation value of a unique natural habitat.