Male African elephants (Loxodonta africana) queue when the stakes are high

Abstract

Linear dominance hierarchies are thought to form within groups of social animals to minimize conflict over access to resources. Dominance in both male and female African elephants (Loxodonta africana) is based mostly on intrinsic factors relating to age, and dominance hierarchies have been described within and between family groups of females. Very little is reported about male elephant social structure and dominance has only been described at the level of one-on-one contests. We test the hypothesis that male African elephants form linear hierarchies when resources are limited by monitoring a known group of elephants in Etosha National Park, Namibia, and measuring dominance interactions between males (outside the context of reproduction) during the dry season of 4 consecutive years. We show that males form a stable linear dominance hierarchy under normal arid conditions (in 2005 and 2007) when water is limited and resource competition is high. In unusually wet years with increased water availability (in 2006 and 2008), there is no linearity to the dominance hierarchy, less interaction between individuals and more agonistic behaviors exhibited, particularly in lower ranking individuals. This is the first study to quantify the existence of a linear dominance hierarchy in male African elephants as well as the effect of climatic fluctuations on dominance from year to year.

The Psychology of Cows

“…Dominance hierarchies can, arguably, be viewed as a higher-order level of social complexity above and beyond group size. Dominance hierarchies serve to reduce group conflicts related to resource appropriation (O'Connell-Rodwell et al, 2011). Dominance hierarchies are widely present across several cognitively-complex mammal taxa, including African elephants (O'Connell-Rodwell et al, 2011), and bonobos (Surbeck, Mundry, & Hohmann, 2011), and including farmed animals such as pigs (Puppe, Langbein, Bauer, & Hoy, 2008) and goats (Miranda-de la Lama, Sepúlveda, Montaldo, María, & Galindo, 2011).…”

Sexual dimorphism in African elephant social rumbles

“…Males leave their natal family at an average age of 14 years, but all-male coalitions and companionship have been reported [23]. Their vocalizations seem to be primarily related to contexts of intra-sexual dominance and reproduction [22].…”

“…African elephants ( Loxodonta africana ) live in matrilineal societies in which most female vocalizations are used for family group and inter-individual cohesion [ 22 ]. Males leave their natal family at an average age of 14 years, but all-male coalitions and companionship have been reported [ 23 ]. Their vocalizations seem to be primarily related to contexts of intra-sexual dominance and reproduction [ 22 ].…”

Decreasing reservoir water levels improve habitat quality for Asian elephants

“…Elephants have a distinct social organization with group-living females and young, and solitary adult males (Douglas-Hamilton, 1972;Moss and Poole, 1983). Resource competition between members is one of the obvious costs of group living (Janson, 1988;O'Connell-Rodwell et al, 2011) and maybe particularly an issue for mega-herbivores. Asian elephants show sexual dimorphism in body size with adult males being around 3302 ± 430 kg and 262 ± 15 cm in height and adult females 2593 ± 298 kg and 235 ± 11 cm in height (Kurt and Kumarasinghe, 1998).…”