Body surface area and thermoregulation in giraffes

dc.contributor.authorMitchell, Graham
dc.contributor.authorVan Sittert, Sybrand J.
dc.contributor.authorRoberts, D.G. (David)
dc.contributor.authorMitchell, Duncan
dc.date.accessioned2017-09-12T05:42:24Z
dc.date.issued2017-10
dc.description.abstractOne of several hypotheses for the evolution of the shape of giraffes is that it evolved to maximize heat loss via a high surface area to mass ratio. We calculated the surface area (SA) of the head, neck, trunk and upper legs, and the lower legs in 60 giraffes of both sexes and a body mass range of 141–1358 kg. No sex differences were found for giraffes of equivalent body mass. Relative surface area (cm2 kg−1 body mass) declined from 145 in juvenile giraffes to 90 in adults. Average total body SA was 7.3 ± 2.5 m2 (range 2.2–11.7), which is not significantly different to that of mammals of equivalent mass. The extra area of the neck and legs was offset by smaller trunk area. However, the narrow diameters of the neck and lower legs enhance the rate of convective and evaporative heat loss and reduce the incident solar radiant heat load when giraffe face the sun, a behaviour supplemented by seeking shade if it is available. We have concluded that giraffes do not have an unusually large SA for their mass, but their shape confers other thermoregulatory benefits that have advantages for survival in the arid habitat they prefer.en_ZA
dc.description.departmentCentre for Veterinary Wildlife Studiesen_ZA
dc.description.embargo2018-10-30
dc.description.librarianhj2017en_ZA
dc.description.sponsorshipThe Don Craib Trust, and the University of Wyoming (GM). SJvS was in receipt of the Maberly Memorial Scholarship and University of Pretoria study bursaries.en_ZA
dc.description.urihttp://www.elsevier.com/locate/jaridenven_ZA
dc.identifier.citationMitchell, G., Van Sittert, S., Roberts, D. & Mitchell, D. 2017, 'Body surface area and thermoregulation in giraffes', Journal of Arid Environments, vol. 145, pp. 35-42.en_ZA
dc.identifier.issn0140-1963 (print)
dc.identifier.issn1095-922X (online)
dc.identifier.other10.1016/j.jaridenv.2017.05.005
dc.identifier.urihttp://hdl.handle.net/2263/62230
dc.language.isoenen_ZA
dc.publisherElsevieren_ZA
dc.rights© 2017 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Arid Environments. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Journal of Arid Environments, vol. 145, pp. 35-42, 2017. doi : 10.1016/j.jaridenv.2017.05.005.en_ZA
dc.subjectGiraffe (Giraffa camelopardalis)en_ZA
dc.subjectBody surface areaen_ZA
dc.subjectThermoregulationen_ZA
dc.subjectWeighten_ZA
dc.subjectMammalsen_ZA
dc.subjectBehavioren_ZA
dc.subjectPhylogenyen_ZA
dc.subjectTopographyen_ZA
dc.subjectOrientationen_ZA
dc.subjectFormulaen_ZA
dc.subjectEvolutionen_ZA
dc.subjectSexual selectionen_ZA
dc.subject.otherVeterinary science articles SDG-15en_ZA
dc.subject.otherSDG-15: Life on land
dc.titleBody surface area and thermoregulation in giraffesen_ZA
dc.typePostprint Articleen_ZA

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