Diurnal, seasonal, and sex patterns of heart rate in grip‐restrained African giant rats (Cricetomys gambianus, Waterhouse)

This study was carried out to determine heart rate (HR) values, including diurnal, seasonal, and sex patterns, in the African giant rat (Cricetomys gambianus, Waterhouse). HR was measured using stethoscope in grip‐restrained African giant rats of either sex (103 bucks and 98 does), live‐trapped from a tropical Savannah, and caged individually in the laboratory during the harmattan (cold‐dry), hot‐dry, and rainy seasons over a 3‐year period. The HR fluctuated between 90 and 210 beats per minute (bpm) throughout the study period. Diurnal changes in HR (mean ± SEM) during the hot‐dry and rainy seasons were nonsignificant (P > 0.05), but the morning and afternoon values differed (P