Savanna elephants maintain homeothermy under African heat

  title={Savanna elephants maintain homeothermy under African heat},
  author={Michael A Mole and Shaun Rodrigues D{\'A}raujo and Rudi J. van Aarde and Duncan Mitchell and Andrea Fuller},
  journal={Journal of Comparative Physiology B},
To conserve body water, mammals may reduce evaporative water loss by storing heat, allowing core body temperature to rise more than usual during the day, and to fall more than usual during the cooler night, so demonstrating heterothermy. It has been proposed that elephants are heterothermic, but body temperature never has been measured in elephants over 24 h at environmental temperatures higher than body temperature, where elephants would have to rely on evaporative cooling to maintain… Expand
5 Citations
How dryland mammals will respond to climate change: the effects of body size, heat load and a lack of food and water
Dryland mammals facing climate change are encountering increasing heat as well as reduced water and food availability as a result of climate change, with compound effects on performance in mammals of varying body size. Expand
Air temperature and diet influence body composition and water turnover in zoo-living African elephants (Loxodonta africana)
This study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2–3 days to avoid critical water loss of approximately 10% body mass in hot conditions. Expand
Obligatory Nocturnalism in Triassic Archaic Mammals: Preservation of Sperm Quality?
  • B. Lovegrove
  • Biology, Medicine
  • Physiological and Biochemical Zoology
  • 2019
This work proposes a hypothesis that, with the onset of body size miniaturization in the Triassic and the concomitant evolution of fur and increased mass-specific metabolic rate and hence body temperature, small mammals became obligatorily nocturnal in order to avoid poor sperm quality, hyperthermia, and high rates of evaporative water loss and to maximize foraging time. Expand
The utilisation of woody species by male and female elephants in the Serengeti National Park, a nutrient-rich savanna
It is suggested that sexual differences in forage requirements interact with forage quality and competing herbivore communities in shaping the foraging behaviour of elephants. Expand
Circadian rhythmicity of body temperature and metabolism
The circadian system modulates metabolic heat production to generate the body temperature rhythm, which challenges homeothermy but does not abolish it, meaning that circadian rhythmicity and metabolism are intertwined in the cell. Expand


Taking the heat: thermoregulation in Asian elephants under different climatic conditions
These responses show all characteristics of heterothermy, and it is concluded that this thermoregulatory strategy is not restricted to desert mammals, but is also employed by Asian elephants. Expand
Coping with heat: behavioural and physiological responses of savanna elephants in their natural habitat
Elephants clearly have the capacity to deal with extreme heat, at least in environments with adequate resources of forage, water and shade, and future conservation actions should provide for the thermoregulatory, resource and spatial needs of elephants. Expand
Body temperature daily rhythm adaptations in African savanna elephants (Loxodonta africana)
The results showed that elephants had lower mean T(b) values than smaller ungulates inhabiting similar environments but did not have larger or smaller amplitudes of T( b) variation, as would be predicted by their exposure to large fluctuations in ambient temperature or their large size. Expand
Climate influences thermal balance and water use in African and Asian elephants: physiology can predict drivers of elephant distribution
It is suggested that classification of elephants as water dependent is insufficient given the importance of climate in determining the magnitude of this dependence and the potential for a physiological modeling approach to predicting the utility of surface water management for specific populations. Expand
Adaptive heterothermy and selective brain cooling in arid-zone mammals.
None of the rete ungulates seems to employ selective brain cooling to prevent the brain overheating during exertional hyperthermia, so it is believed that they use it at rest, under moderate heat load, in order to switch body heat loss from evaporative to non-evaporative routes. Expand
Heat storage in Asian elephants during submaximal exercise: behavioral regulation of thermoregulatory constraints on activity in endothermic gigantotherms
This work sought to test the hypothesis that there is a functionally significant relationship between heat storage and locomotion in Asian elephants, and model the thermoregulatory constraints on activity in elephants and a similarly sized migratory dinosaur, Edmontosaurus. Expand
Heterothermy in large mammals: inevitable or implemented?
It is proposed that the amplitude of the 24 h rhythm of body core temperature provides a useful index of any compromise experienced by a free‐living large mammal and may predict the performance and fitness of an animal. Expand
Daily regulation of body temperature rhythm in the camel (Camelus dromedarius) exposed to experimental desert conditions
It is highlighted that adaptive heterothermy in the Arabian camel varies across the diurnal light–dark cycle and is modulated by timing of daily heat and degrees of water restriction and associated reduction of food intake, points to a possible mechanism of internal desynchronization during the process of adaptation to desert environment. Expand
Variation in the daily rhythm of body temperature of free-living Arabian oryx (Oryx leucoryx): does water limitation drive heterothermy?
Body temperature variability was influenced not only by ambient temperature but also water availability, with oryx displaying larger daily amplitudes of the body temperature rhythm during warm-dry months compared to warm-wet months, even though ambient temperatures were the same. Expand
Daily torpor and hibernation in birds and mammals
  • T. Ruf, F. Geiser
  • Biology, Medicine
  • Biological reviews of the Cambridge Philosophical Society
  • 2015
The analysis strongly supports the view that hibernators and daily heterotherms are functionally distinct groups that probably have been subject to disruptive selection. Expand