Effect of tail loss on sprint speed and growth in newborn skinks, Niveoscincus metallicus

Most studies that examined effects of caudal autotomy on lizards focused on adults and largely neglected the potential for contrasting effects in newborns and juveniles. We examined the impact of tail autotomy on locomotor performance and growth in newborn Metallic Skinks, Niveoscincus metallicus. Two siblings were randomly selected from each of 12 litters, with one assigned to a control group (tail intact) and the other to an experimental group (tail removed). Removal of the tail at the base 24 h after birth resulted in a significant decrease in sprint speed 72 h after birth (approximately 50% reduction compared to speed within 24 h of birth). This impairment is substantially greater than that observed previously in adults of this species (35%). However, caudal autotomy at birth did not inhibit growth, measured as the increase in snout-vent length, during the first eight weeks of life. Despite maintaining growth rate, newborns were still able to regenerate at least one-third of their tail over the eight weeks of the study. We discuss how the absence of the tail, the presumed energetic cost of tail replacement, and the lack of caudal fat stores, may influence the ability of newborn N. metallicus to survive their first winter.