Cruise's investigation centred on African savanna elephants (Loxodonta africana). The choice of elephants is an important point of reference in measuring the efficacy of Namibia's conservation model. Biologists often refer to African elephants as keystone species or ecosystem 'architects' and 'gardeners'. Their presence in the natural landscape increases and helps support the overall biodiversity and well-being of other wild species. Their presence, or lack thereof, also serves as a gauge with which to measure the overall health of an environment. African elephants are also an 'umbrella species' in that they require large areas of suitable habitat. They require vast ranges to roam and large, intact natural areas to maintain their populations. By protecting such vast areas in which they are, themselves, secure, many other species that share habitat with elephants are ultimately protected too. Sasada's investigation centred on the rural communities and indigenous peoples living within the conservancies and surrounding areas. The focus of her investigation was to gauge the perceived success of Namibia's conservation model with local community members and indigenous peoples both in terms of economic benefits and wildlife/elephant conservation.