Summary: McComb et al. (2014)

An animals' ability to perceive and recognize predators, as well as assess the threat they pose, is crucial for the survival and persistence of the individual and, by extension, the species. By assessing the threat, animals can minimise the cost of retreating if the threat is unfounded, while maximising the time spent engaged in other activities. While most small-bodied animals are faced with a variety of predator threats, larger-bodied species, such as elephants Loxodonta africana may not experience the same pressure from predation. However, elephants and other large-bodied animals are at risk of predation by humans, due to humans increased cognitive ability to hunt these larger-bodied resources. McComb et al. (2014) investigated elephant responses to vocal playbacks of different humans in Amboseli National Park, Kenya. They tested whether elephants responded differently to 1) adult male human voices from two different ethnic groups (Maasai and Kamba), 2) male and female human vocalizations; and 3) young male human voices (boys). They resynthesised the adult male vocalizations to mimic female voices. McComb et al. (2014) found that elephants used more defensive bunching postures and investigative smelling following adult male Maasai vocalizations, compared to Kamba male vocalizations, consistent with the high predation threat imposed by this group of humans. In addition, elephants were less likely to demonstrate a strong behavioural response to female and young boy vocalizations, indicating an ability to distinguish between different vocal qualities. While McComb et al. (2014) suggest that this may be a function of selection in these cognitively advanced animals, with increasing human pressure, it would be interesting to determine whether this is a more general response than expected.