title: Improved homeothermy and hypothermia in African lions during gestation.
abstract: Mammals use endogenously produced heat to maintain a high and relatively constant core body temperature (Tb). How they regulate their Tbduring reproduction might inform us as to what thermal conditions are necessary for optimal development of offspring. However, few studies have measured Tbin free-ranging animals for sufficient periods of time to encounter reproductive events. We measured Tbcontinuously in six free-ranging adult female African lions (Panthera leo) for approximately 1 year. Lions reduced the 24 h amplitude of Tbby about 25% during gestation and decreased mean 24 h Tbby 1.3 ± 0.1°C over the course of the gestation, reducing incidences of hyperthermia (Tb> 39.5°C). The observation of improved homeothermy during reproduction may support the parental care model (PCM) for the evolution of endothermy, which postulates that endothermy arose in birds and mammals as a consequence of more general selection for parental care. According to the PCM, endothermy arose because it enabled parents to better control incubation temperature, leading to rapid growth and development of offspring and thus to fitness benefits for the parents. Whether the precision of Tbregulation in pregnant lions, and consequently their reproductive success, will be influenced by changing environmental conditions, particularly hotter and drier periods associated with climate change, remains to be determined.
authors.affiliation: Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK trethowan.zoology@gmail.com.
authors.forename: Paul D
authors.identifier: 0000-0001-8245-6113
authors.initials: PD
authors.lastname: Trethowan
authors.affiliation: Ocean Research and Conservation Group, Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Hart
authors.affiliation: Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Loveridge
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Anna
authors.initials: A
authors.lastname: Haw
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
authors.affiliation: Wildlife Conservation Research Unit, The Recanati-Kaplan Centre, Department of Zoology, University of Oxford, Oxford, UK.
authors.forename: David W
authors.initials: DW
authors.lastname: Macdonald
mesh_terms: D000818:Animals; D005260:Female; D008045:Lions / Q000502:physiology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D022722:Thermogenesis / Q000502:physiology*
keywords: Panthera leo; endothermy; evolution; parental care