Diurnal, seasonal and sex variations in rectal temperature of African giant rats ( Cricetomys gambianus, Waterhouse)

Abstract

(1) Rectal temperature ( T r) was measured in captive African giant rats ( Cricetomys gambianus, Waterhouse), live-trapped in the Savannah during the harmattan, hot-dry and rainy seasons with the aim of determining diurnal, seasonal and sex patterns. (2) Mean (±SEM) T r in the morning (37.16±0.04 °C) was lower ( P<0.001) than the afternoon (37.49±0.03 °C) and evening (37.66±0.03 °C). There was no significant difference ( P>0.05) between afternoon and evening T r during the harmattan and rainy seasons, but the difference was significant ( P<0.001) during the hot-dry season. Overall T r was higher ( P<0.001) during the hot-dry (38.03±0.03 °C) than harmattan (37.17±0.03 °C) and rainy (37.21±0.03 °C) seasons. T r of bucks was lower than that of does ( P<0.0001) during the harmattan and rainy seasons, but sex difference during the hot-dry season was not significant ( P>0.05). (3) Base-line T r values for the African giant rats are shown for the first time. Season, time of day and sex influence fluctuations in T rs of African giant rats, and should be considered during diagnostic and clinical evaluations.