Arboreal Behavior of Captive Acacia Rats Thallomys paedulcus (Rodentia: Muridae)

Arboreal locomotion in small mammals requires the integration of behavioral and morphological adaptations to negotiate complex three-dimensional environments. The present study investigates the locomotor and postural behavior of captive Acacia rats (Thallomys paedulcus) to evaluate their arboreal capacities. A total of 21 adult individuals were observed under controlled conditions, and behavioral data were collected from video recordings using continuous bout sampling. Substrate size, inclination, and type were recorded alongside locomotor and postural modes, and substrate preferences were assessed relative to availability. Results show that Acacia rats predominantly used arboreal substrates, with a strong preference for small-diameter and horizontal supports during both locomotion and postural activities. Quadrupedalism was the dominant locomotor mode, followed by climb and clamber, while bridge and leap were used for gap crossing. Postural behavior was mainly characterized by stand, with less frequent sit, bipedal stand, and cling. Medium and large substrates, as well as oblique and vertical supports, were generally avoided, particularly during postural behavior. These findings indicate a high degree of behavioral specialization for exploiting fine terminal branches within tree canopies. The results support the arboreal propensities of Acacia rats, with adaptations primarily expressed through behavioral selectivity rather than morphological divergence. This study contributes to understanding the ecological and functional adaptations of small arboreal mammals and highlights the importance of structurally complex habitats for their survival.