Hofmeyer, MDBennett, NCooper, HMThomas, D2023-06-122024-11-042023-06-122024-11-042001https://hdl.handle.net/10566/17257>Magister Scientiae - MScAlthough humans are diurnal in behavior, animal models used for the study of circadian rhythms are mainly restricted to nocturnal rodents. This study focused on circadian behavior and gene expression in a diurnal rodent from South Africa, the four-striped field mouse (Rhabdomys pumilio). In contrast to nocturnal rodents which have rod-dominated retinas, the retina of this field mouse contained approximately an equal amount of cones as rods. The cones included short-wavelength (blue-sensitive) and mid-wavelength (green-sensitive) cones. In order to characterize the behavioral pattern of daily activity, locomotor rhythms were studied under different light regimes using an automated data recording system. Under conditions of natural daylight which include dawn and dusk transitions, R. pumilio showed activity restricted to the daytime period. Activity was concentrated around morning and evening hours with a decrease during mid-day.entwilighttaumaskingdiurnalityactivity plan