Losing stability: tail loss and jumping in the arboreal lizardAnolis carolinensis

Abstract

SUMMARYVoluntary loss of an appendage, or autotomy, is a remarkable behavior that is widespread among many arthropods and lower vertebrates. Its immediate benefit, generally escape from a predator, is balanced by various costs, including impaired locomotor performance, reproductive success and long-term survival. Among vertebrates, autotomy is most widespread in lizards, in which tail loss has been documented in close to 100 species. Despite numerous studies of the potential costs of tail autotomy in lizards, none have focused on the importance of the tail in jumping. Using high-speed video we recorded jumps from six lizards (Anolis carolinensis) both before and after removing 80% of the tail to test the hypothesis that tail loss has a significant effect on jumping kinematics. Several key performance metrics, including jump distance and takeoff velocity, were not affected by experimental tail removal, averaging 21 cm and 124 cm s Supplementary material available online at

Total recoil: perch compliance alters jumping performance and kinematics in green anole lizards (Anolis carolinensis)

“…The negative landing angles appeared to be caused by the perch striking the lizard tail upon recoil (supplementary material Movie1). We observed that when lizards jumped from rigid perches, they often dragged their tail along the perch during takeoff, as also noted in a previous study (Gillis et al, 2009). When jumping from compliant perches, the part of the tail that was still in contact with (or sometimes above) the perch was struck when the perch recoiled, thus lifting the tail and ultimately changing the body position of the lizard during flight and landing (Fig.3A).…”

“…Lizards jumped from the rigid perch with the same general kinematics as seen in other studies (Bels et al, 1992;Gillis et al, 2009): the jump started with placement of the hind feet towards the front of the body; lizards then used their hind limbs to propel themselves forward with a mean positive body angle of 12.1±1.7deg and a mean speed and duration of 130.4±2.6cms -1 and 0.1±0s. After the takeoff phase, the aerial phase followed with the forelimbs limbs tucked close to the body, and lizards landed with the body angled so that the hind feet contacted the landing substrate first (26.7±4.2deg), at a mean distance of 34.4±0.9cm.…”

“…For example, there are 400+ species of Anolis lizards, the majority of which use a variety of arboreal habitats and regularly use jumping to move around (Irschick and Losos, 1999). Anole ecology and locomotion has been widely studied (Calsbeek and Irschick, 2007;Irschick and Losos, 1999;Losos and Sinervo, 1989;Spezzano and Jayne, 2004;Vanhooydonck et al, 2006), although one anole species has been particularly well studied in terms of jumping, namely the green anole, A. carolinensis Voigt 1832 (Bels et al, 1992;Gillis et al, 2009;Kuo et al, 2011;Losos and Irschick, 1996;Toro et al, 2003;Vanhooydonck et al, 2005). However, the effect of perch compliance on this species, or any small (<65g) species, is unknown.…”

More than a safety line: jump-stabilizing silk of salticids

“…Besides adjusting the centre of mass (CoM) close to the vector of propulsive thrust at take-off to avoid later body rotation [7,8], some jumpers actively use dynamic control for in-air stability. Two mechanisms have previously been proposed to counteract unwanted torque in the air: using the inertia of swinging appendages [9][10][11][12] and aerodynamic forces from flapping wings [6,7]. Take-off mechanisms and stability control that evolved in nature have led to significant progress in bioinspired designs for manoeuvrable jumping robots [11,13].…”

Current Understanding on Tail Regeneration in Green Anoles (Anolis carolinensis)

“…Lizards control their body position in midair during jumping and falling by swinging through air and interacting with takeoff surface. Studies of ground reaction forces (GRFs), moment of inertia and center of mass (CoM) in lizards before and after autotomy showed that changes in these parameters may cause negative impacts on the body dynamics during jumping and falling [48,49,52]. For example, locomotive changes (i.e., morphology, GRFs and kinematics) in Eublepharis macularius due to autotomy, resulted in 13% of anterior shift of CoM.…”