The locomotory activity patterns of the arid-dwelling desert hedgehog, Paraechinus aethiopicus, from Saudi Arabia

Abstract

The animal-environment interaction is complex, and the ability to temporally organise locomotor activity provides adaptive and survival advantages. The daily and circadian rhythms of locomotor activity in the Desert hedgehog, Paraechinus aethiopicus, from the central deserts of Saudi Arabia were investigated under controlled laboratory conditions. Twelve individuals were subjected to different light cycles of approximately 3 weeks each: light/dark (12:12LD) cycle; a period of constant darkness (DD); an inverse of the LD (12:12 DL) cycle; a short day cycle (8:16LD); and a long day cycle (16:8LD). All the animals exhibited entrainment of their activity to the LD and DL lighting regimes. Locomotor activity of the Desert hedgehog occurred mostly during the dark phases of the LD, DL, long day and short day cycles. All entraining hedgehogs showed daily rhythmicity, with the periods of the rhythms very close to 24 h. Entrained hedgehogs, additionally, inversed their activity patterns when the light cycle was inversed. The Desert hedgehog, therefore, can be described as genuinely nocturnal with an endogenous rhythm of locomotor activity.