title: Fever and sickness behavior during an opportunistic infection in a free-living antelope, the greater kudu (Tragelaphus strepsiceros).
abstract: To study their thermal responses to climatic stress, we implanted seven greater kudu (Tragelaphus strepsiceros) with intra-abdominal, brain, carotid, and subcutaneous temperature data loggers, as well as an activity logger. Each animal was also equipped with a collar holding a miniature black globe thermometer, which we used to assess thermoregulatory behavior. The kudu ranged freely within succulent thicket vegetation of the Eastern Cape Province, South Africa. The kudu spontaneously developed a bacterial pneumonia and consequent fever that lasted between 6 and 10 days. The fever was characterized by a significant increase in mean 24-h abdominal temperature from 38.9 +/- 0.2 degrees C to 40.2 +/- 0.4 degrees C (means +/- SD, t(6) = 11.01, P < 0.0001), although the amplitude of body temperature rhythm remained unchanged (t(6) = 1.18, P = 0.28). Six of the kudu chose warmer microclimates during the fever than when afebrile (P < 0.0001). Despite the selection of a warmer environment, on the first day of fever, the abdominal-subcutaneous temperature difference was significantly higher than on afebrile days (t(5) = 3.06, P = 0.028), indicating vasoconstriction. Some kudu displayed increased frequency of selective brain cooling during the fever, which would have inhibited evaporative heat loss and increased febrile body temperatures, without increasing the metabolic maintenance costs of high body temperatures. Average daily activity during the fever decreased to 60% of afebrile activity (t(6) = 3.46, P = 0.014). We therefore have recorded quantitative evidence for autonomic and behavioral fever, as well as sickness behavior, in the form of decreased activity, in a free-living ungulate species.
authors.affiliation: Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa. robyn.hetem@gmail.com
authors.forename: Robyn S
authors.initials: RS
authors.lastname: Hetem
authors.forename: Duncan
authors.initials: D
authors.lastname: Mitchell
authors.forename: Shane K
authors.initials: SK
authors.lastname: Maloney
authors.forename: Leith C R
authors.initials: LC
authors.lastname: Meyer
authors.forename: Linda G
authors.initials: LG
authors.lastname: Fick
authors.forename: Graham I H
authors.initials: GI
authors.lastname: Kerley
authors.forename: Andrea
authors.initials: A
authors.lastname: Fuller
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000382:microbiology / Q000502:physiology*; D000866:Antelopes / Q000382:microbiology / Q000502:physiology*; D001424:Bacterial Infections / Q000382:microbiology / Q000503:physiopathology / Q000662:veterinary*; D001522:Behavior, Animal / Q000502:physiology*; D001831:Body Temperature / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D001921:Brain / Q000503:physiopathology; D002980:Climate; D005260:Female; D005334:Fever / Q000382:microbiology / Q000503:physiopathology / Q000662:veterinary*; D009894:Opportunistic Infections / Q000382:microbiology / Q000503:physiopathology / Q000662:veterinary*; D013019:South Africa; D013312:Stress, Physiological