Investigación de fauna amenazada en medios remotos: el caso de la gacela de Cuvier (Gazella cuvieri Ogilby, 1841) en el desierto del Sahara

Abstract

In recent decades, empirical studies on fauna and flora involving fieldwork have declined, although basic information on key aspects of the biology and ecology of many species is lacking. This lack of knowledge has negatively affected decisions made by governments regarding biodiversity conservation plans. The need to increase our basic knowledge of the status and ecology of species is more urgent than ever, particularly in remote areas of the planet, where the absence of information is very noticeable. The Sahara Desert is one such remote area where basic data are lacking to develop well-designed conservation actions. There, overhunting and habitat destruction have a disastrous impact on the ecosystem, which has consequently lost much of its integrity and functionality. Cuvier's gazelle (Gazella cuvieri Ogilby, 1841) is a medium-sized ungulate endemic to North Africa that is threatened by precisely these anthropogenic pressures. Despite being listed as "Vulnerable" by the International Union for Conservation of Nature (IUCN), the lack of knowledge about its biology and actual conservation status may be leading to a lack of protection and even local extinctions. Cuvier's gazelle is part of the Sahelo-Saharan antelope group, a guild that has developed physiological and behavioural strategies to survive in extreme conditions. The southernmost population of Cuvier's gazelle is located in the Atlantic quadrant of the Sahara Desert, in a region of hyper-arid climate within the ecoregion of the Xerophytic Steppe and Forests of the Northern Sahara. Despite the limiting conditions in which this population inhabits, this species survives there due to its great resilience and adaptation to the extreme conditions of the environment. This thesis was carried out in an area of approximately 20,000 km2 in this region of the Sahara Desert, more specifically in the north-western sector of the Atlantic Sahara. The general objective was to assess the regional conservation status of the species and to increase knowledge of its biology, ecological traits and adaptations at the southwestern limit of its distribution. The specific objectives included the evaluation of its distribution and population size, the identification of the factors that determine its presence with the generation of predictive distribution models, and the analysis of its diet, activity rhythm and relationships with predators and humans. The pioneering nature of this work should be highlighted, not only because of its magnitude (both spatial and temporal) and the aspects covered, but also because it has focused on a totally wild population of a North African ungulate as the object of study. Surprisingly, this is an exceptional approach in the recent context of research on Saharan ungulates, where studies on reintroduced populations in semi-freedom (within fenced areas) are the norm.