Monitoring rarity: the critically endangered Saharan cheetah as a flagship species for a threatened ecosystem

Abstract

Deserts are particularly vulnerable to human impacts and have already suffered a substantial loss of biodiversity. In harsh and variable desert environments, large herbivores typically occur at low densities, and their large carnivore predators occur at even lower densities. The continued survival of large carnivores is key to healthy functioning desert ecosystems, and the ability to gather reliable information on these rare low density species, including presence, abundance and density, is critical to their monitoring and management. Here we test camera trap methodologies as a monitoring tool for an extremely rare wide-ranging large felid, the critically endangered Saharan cheetah (Acinonyx jubatus hecki). Two camera trapping surveys were carried out over 2-3 months across a 2,551 km2 grid in the Ti-n-hağğen region in the Ahaggar Cultural Park, south central Algeria. A total of 32 records of Saharan cheetah were obtained. We show the behaviour and ecology of the Saharan cheetah is severely constrained by the harsh desert environment, leading them to be more nocturnal, be more wide-ranging, and occur at lower densities relative to cheetah in savannah environments. Density estimates ranged from 0.21-0.55/1,000 km2, some of the lowest large carnivore densities ever recorded in Africa, and average home range size over 2-3 months was estimated at 1,583 km2. We use our results to predict that, in order to detect presence of cheetah with p>0.95 a survey effort of at least 1,000 camera trap days is required. Our study identifies the Ahaggar Cultural Park as a key area for the conservation of the Saharan cheetah. The Saharan cheetah meets the requirements for a charismatic flagship species that can be used to "market" the Saharan landscape at a sufficiently large scale to help reverse the historical neglect of threatened Saharan ecosystems.

Figure 1. Study area, detailing the location of the study area and the surveyed region.

Figure 2. Time of cheetah captures across the two surveys in 2008 and 2010.

Data covers 32 captures of 5 different individuals.

Figure 3. Survey effectiveness at delivering abundance and presence estimates with increasing survey effort measured in camera trap days (number of camera traps × number of days of survey).

a) Accumulation graph of number of individuals captured during surveys; b) probability of detecting at least one cheetah with increasing effort, keeping the number of camera stations constant; and c) probability of detecting at least one cheetah with increasing effort, keeping the survey duration constant. The vertical lines in b) and c) depict the number of camera trap days that result in 95% probability of detecting presence.