Prey Capture Behavior in the Blue-Tongued Skink, Tiliqua scincoides

Libourel³

et al. 2009

Self Cite

SUMMARYIn tetrapods, feeding behaviour in general, and prey capture in particular, involves two anatomical systems: the feeding system and the locomotor system. Although the kinematics associated with the movements of each system have been investigated in detail independently, the actual integration between the two systems has received less attention. Recently, the independence of the movements of the jaw and locomotor systems was reported during tongue-based prey capture in an iguanian lizard (Anolis carolinensis), suggesting a decoupling between the two systems. Jaw prehension, on the other hand, can be expected to be dependent on the movements of the locomotor system to a greater degree. To test for the presence of functional coupling and integration between the jaw and locomotor systems, we used the cordyliform lizard Gerrhosaurus major as a model species because it uses both tongue and jaw prehension. Based on a 3-D kinematic analysis of the movements of the jaws, the head, the neck and the forelimbs during the approach and capture of prey, we demonstrate significant correlations between the movements of the trophic and the locomotor systems. However, this integration differs between prehension modes in the degree and the nature of the coupling. In contrast to our expectations and previous data for A. carolinensis, our data indicate a coupling between feeding and locomotor systems during tongue prehension. We suggest that the functional integration between the two systems while using the tongue may be a consequence of the relatively slow nature of tongue prehension in this species. Supplementary material available online at

Section: Discussionsupporting

confidence: 61%

Section: Prey Prehension Modessupporting

confidence: 65%

Locomotor–feeding coupling during prey capture in a lizard(Gerrhosaurus major): effects of prehension mode

Montuelle¹,

Libourel³

et al. 2009

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“…Meyers and A. Herrel Schwenk and Throckmorton, 1989;Delheusy and Bels, 1992;Herrel et al, 1995) and displays the kinematic phases characteristic of the generalized lower tetrapod feeding model (Bramble and Wake, 1985). Although this model was originally developed to describe prey processing and transport, it has been aptly applied to prey capture as well Bels, 1992, 1999;Herrel et al, 1995;Smith et al, 1999) and will be used here to describe the general features of the prey capture cycle in the four species. However, in our descriptions, we combined the slow open I (SOI) and slow open II (SOII) phases, as they were not always clearly distinguishable during prey capture events.…”

Section: General Feeding Behaviormentioning

confidence: 99%

Prey capture kinematics of ant-eating lizards

Meyers

2005

While morphological and behavioral feeding specializations are obvious in many vertebrate groups, among lizards there appear to be few dietary specialists. By comparing the prey capture kinematics and overall feeding behavior in two highly specialized ant-eating lizards (Moloch horridus and Phrynosoma platyrhinos) with those of two closely related dietary generalists (Pogona vitticeps and Uma notata), we investigate whether dietary specialization has been accompanied by changes in the function and use of the feeding system. We quantified kinematic variables from high-speed video recordings (200-250·frames·s -1 ) of each species feeding on ants. Prey capture was strikingly different in M. horridus to that of other species, being characterized by a suite of unusual behaviors including the lack of a body lunge, faster tongue protrusion, reduced prey processing and, most notably, the ability to modulate the slow open phase of the gape cycle. In concert, these traits make a single feeding event in M. horridus faster than that in any other iguanian lizard studied to date. Prey capture behavior in P. platyrhinos is kinematically more similar to U. notata and P. vitticeps than to M. horridus, but the ant specialists are similar in that both lack distinct prey processing behaviors, resulting in faster overall capture and feeding events. While ant feeding in P. vitticeps is faster than feeding on other prey, the duration of a single feeding event is still four times longer than in either ant specialist, because of extensive prey processing. Additionally, a phylogenetic comparison of ant specialist lizards with dietary generalists revealed that ant-eating lizards require significantly less time to capture and process prey. Thus there are not only significant behavioral modifications in these ant-eating lizards, but also multiple strategies among specialists, suggesting differing selective pressures or phylogenetic constraints in the evolution of ant eating in lizards.

“…Such variability in feeding movements has been documented extensively in squamate lizards during both the capture and intra-oral transport and processing of food (e.g. Bels and Baltus, 1988;Herrel et al, 1996;Herrel et al, 1999;Smith et al, 1999;Schaerlaeken et al, 2007;Schaerlaeken et al, 2008;Sherbrooke and Schwenk, 2008;Metzger, 2009;Montuelle et al, 2010;Schaerlaeken et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Similar to some other cordyliform lizards, the prey-capture behavior in G. major is characterized by a switch between tongue prehension and jaw prehension depending on prey type (Urbani and Bels, 1995;Smith et al, 1999;Reilly and McBrayer, 2007;Montuelle et al, 2009a). From a motor control perspective, each prey prehension mode stems from two different integrative motor patterns that coordinate feeding movements (i.e.…”

Section: Introductionmentioning

confidence: 99%

Flexibility in locomotor-feeding integration during prey capture in varanid lizards: effects of prey size and velocity

Montuelle

Libourel

et al. 2012

SUMMARYFeeding movements are adjusted in response to food properties, and this flexibility is essential for omnivorous predators as food properties vary routinely. In most lizards, prey capture is no longer considered to solely rely on the movements of the feeding structures (jaws, hyolingual apparatus) but instead is understood to require the integration of the feeding system with the locomotor system (i.e. coordination of movements). Here, we investigated flexibility in the coordination pattern between jaw, neck and forelimb movements in omnivorous varanid lizards feeding on four prey types varying in length and mobility: grasshoppers, live newborn mice, adult mice and dead adult mice. We tested for bivariate correlations between 3D locomotor and feeding kinematics, and compared the jaw-neck-forelimb coordination patterns across prey types. Our results reveal that locomotor-feeding integration is essential for the capture of evasive prey, and that different jaw-neck-forelimb coordination patterns are used to capture different prey types. Jaw-neck-forelimb coordination is indeed significantly altered by the length and speed of the prey, indicating that a similar coordination pattern can be finely tuned in response to prey stimuli. These results suggest feed-forward as well as feed-back modulation of the control of locomotor-feeding integration. As varanids are considered to be specialized in the capture of evasive prey (although they retain their ability to feed on a wide variety of prey items), flexibility in locomotor-feeding integration in response to prey mobility is proposed to be a key component in their dietary specialization.