Resource Use in Arboreal Habitats: Structure Affects Locomotion of Four Ecomorphs of Anolis Lizards

Abstract

Previous laboratory studies have frequently determined the maximal running speeds of lizards. However, neither the extent to which animals use maximal speeds in nature nor the effects of arboreal habitat structure on undisturbed speeds of locomotion have been well documented. Furthermore, quantitative data describing the physical structure of arboreal habitats are lacking. Thus, we quantified available habitat, perch use, and the undisturbed locomotor behavior of four syntopic ecomorphs of Anolis lizards (A. sagrei, A. distichus, A. carolinensis, and A. angusticeps) in the field. Fifty percent of the cumulative perch length available in the habitat had values of diameter, length, and incline <0.8 cm, 54 cm, and 67°, respectively, indicating that narrow, short, and steep perches dominated the study site. The selection of all perch attributes by A. distichus was biased, whereas each of the remaining species randomly used at least one of the three attributes describing perch structure. Narrow breadth of resource use most often reflected the narrow breadth of available resources rather than selective use of resources. Interestingly, the behavioral and morphological specializations of A. angusticeps facilitate the use of the most common type of perch (twig) rather than a rare resource. Based on median values, the undisturbed speeds and distances of locomotion of A. sagrei (8.9 cm/s and 5.3 cm), A. distichus (31.5 cm/s and 2.8 cm), A. carolinensis (1.6 cm/s and 5.0 cm), and A. angusticeps (2.7 cm/s and 3.9 cm) were exceedingly slow and short, suggesting that neither maximal sprinting speeds nor endurance capacities were used frequently by any species in the field. The effects of habitat structure on undisturbed locomotor speeds and movement distances were highly species specific.

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

“…Recent work has shown the value of examining locomotion in nature, and how animals interact with habitat structure (Fulton et al, 2001;Irschick and Losos, 1999;Johansen et al, 2007;Mattingly and Jayne, 2004;Youlatos and Samaras, 2011). Green anoles in the wild segregate perches across age or sex classes based on perch diameter: smaller animals use narrow perches, and larger animals use larger perches (Irschick et al, 2005a).…”

“…Bonser, 1999;Spezzano and Jayne, 2004;Vanhooydonck et al, 2006). For arboreal animals, the interaction between individuals and their habitat can be complex because of the variability in perch characteristics, such as diameter, length, angle and compliance (Irschick and Losos, 1999;Mattingly and Jayne, 2004). Perch compliance may be of particular concern for arboreal animals that use jumping as a means of moving through their habitat because of the high forces generated during takeoff (Crompton et al, 1993).…”

A new angle on clinging in geckos: incline, not substrate, triggers the deployment of the adhesive system

“…Among vertebrates, lizards are incredibly adept at moving through complex three-dimensional habitats (Higham et al 2001;Higham & Jayne 2004;Mattingly & Jayne 2004). Whereas many lizards employ claws or prehensile feet to cling to the substrate, geckos are noteworthy among relatively large animals (body mass range 1-50 g) in being able to temporarily and reversibly bond with substrata (Dellit 1934;Hiller 1968;Maderson 1970;Autumn et al 2000) that range from the molecularly smooth (Autumn et al 2002) to the macroscopically rough (Russell & Johnson 2007).…”

Why arboreal snakes should not be cylindrical: body shape, incline and surface roughness have interactive effects on locomotion

“…In natural vegetation many aspects of the size and structure of surfaces are correlated to each other (Mattingly and Jayne, 2004). Consequently, experimental manipulations are very useful for decoupling these traits and isolating which factors are causally related to variation in performance and behaviour.…”

“…For example, challenges for moving on branches in arboreal habitats include: (1) balancing on narrow cylindrical surfaces, (2) lifting the weight of the animal up inclines and (3) preventing slipping around the circumference of branches or down inclines (Cartmill, 1985). For a variety of limbed and limbless vertebrates, previous studies have quantified the effects on performance of variation in arboreal habitat structure such as surface diameter, the presence and spacing of secondary branches, and inclines (Irschick and Losos, 1999;Mattingly and Jayne, 2004;Astley and Jayne, 2009;Hyams et al, 2012;Jones and Jayne, 2012;Jayne et al, 2013). The roughness of tree bark also varies considerably among different species and among different branches within a single tree (Ferrenberg and Mitton, 2014), but the effects of surface roughness are poorly understood for the locomotion not only of arboreal animals but also of animals in general.…”