title: Coping with heat: behavioural and physiological responses of savanna elephants in their natural habitat.
abstract: Most of southern Africa's elephants inhabit environments where environmental temperatures exceed body temperature, but we do not know how elephants respond to such environments. We evaluated the relationships between apparent thermoregulatory behaviour and environmental, skin and core temperatures for tame savanna elephants (Loxodonta africana) that were free-ranging in the hot parts of the day, in their natural environment. Environmental temperature dictated elephant behaviour within a day, with potential consequences for fine-scale habitat selection, space use and foraging. At black globe temperatures of ~30°C, elephants adjusted their behaviour to reduce environmental heat load and increase heat dissipation (e.g. shade use, wetting behaviour). Resting, walking and feeding were also influenced by environmental temperature. By relying on behavioural and autonomic adjustments, the elephants maintained homeothermy, even at environmental temperatures exceeding 40°C. Elephants clearly have the capacity to deal with extreme heat, at least in environments with adequate resources of forage, water and shade. Future conservation actions should provide for the thermoregulatory, resource and spatial needs of elephants.
authors.affiliation: Conservation Ecology Research Unit, Department of Zoology and Entomology , University of Pretoria , Pretoria , South Africa.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Mole
authors.affiliation: Conservation Ecology Research Unit, Department of Zoology and Entomology , University of Pretoria , Pretoria , South Africa.
authors.forename: Shaun
authors.initials: S
authors.lastname: Rodrigues DÁraujo
authors.affiliation: Conservation Ecology Research Unit, Department of Zoology and Entomology , University of Pretoria , Pretoria , South Africa.
authors.forename: Rudi J
authors.initials: RJ
authors.lastname: van Aarde
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa.
authors.forename: Duncan
authors.initials: D
authors.lastname: Mitchell
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences , University of the Witwatersrand , Johannesburg , South Africa.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fuller
keywords: Behaviour; homeothermy; savanna elephant; thermal imaging; thermoregulation