Movement- and attack-based indices of foraging mode and ambush foraging in some gekkonid and agamine lizards from southern Africa

AbstractMost lacertids are active foragers, but intrafamilial variation in foraging mode is greater than in most lizard families. We collected data on eight species of African lacertids to assess this variation. Both active and ambush foraging occurred within Pedioplanis and Meroles. Meroles ctenodactylus had a proportion of time moving and proportion of attacked prey detected while moving intermediate to those for actively foraging and ambushing Pedioplanis, but its number of movements per minute was exceptionally high. This species has a unique mixed foraging mode. Like active foragers, it seeks food by tongue-flicking while moving and spends a high percentage of the time moving. Like ambush foragers, it searches visually for prey during pauses between movements. Our findings confirm published data on four Kalahari lacertids. We discuss the history of foraging modes in advanced lacertids.

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Movement- and attack-based indices of foraging mode and ambush foraging in some gekkonid and agamine lizards from southern Africa

Amphibia-Reptilia ◽

10.1163/156853899x00439 ◽

1999 ◽

Vol 20 (4) ◽

pp. 391-399 ◽

Cited By ~ 9

Author(s):

Martin J. Whiting ◽

P. le F.N. Mouton ◽

Johannes H. Van Wyk ◽

William E. Cooper

Keyword(s):

Foraging Behavior ◽

Southern Africa ◽

Preliminary Data ◽

Quantitative Data ◽

Rank Correlation ◽

Foraging Activity ◽

Foraging Mode ◽

Foraging Modes ◽

Ambush Foraging ◽

Very High

AbstractTwo lizard foraging modes, ambush and active foraging, are usually quantified by the variables MPM (movements per minute) and PTM (proportion of time spent moving), but both variables may be affected by behaviors other than foraging. We introduce PAM, the proportion of attacks on prey discovered while lizards are moving (in relation to total attacks). PAM focuses exclusively on foraging behavior. Preliminary data reveal a very high, significant rank correlation between PAM and PTM, and a fairly high, but nonsignificant correlation between PAM and MPM. Collection of PAM data can be very time-consuming. In the absence of PAM, PTM appears to be a superior index of foraging activity to MPM, but all three indices provide valuable information on different aspects of foraging. We additionally present data for four agamine and five gekkonid species from southern Africa. The first quantitative data for agamines (all for Agama) agree with previous qualitative assessments that members of several agamine genera are ambush foragers. All the gekkonids, including three species of Rhotropus and one each of Pachydactylus and Phyllodactylus, are ambush foragers, like most geckos studied to date.

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Do lingual behaviors and locomotion by two gekkotan lizards after experimental loss of bitten prey indicate chemosensory search?

Amphibia-Reptilia ◽

10.1163/156853896x00405 ◽

1996 ◽

Vol 17 (3) ◽

pp. 217-231 ◽

Cited By ~ 1

Author(s):

Christopher S. DePerno ◽

William E. Cooper ◽

Laura J. Steele

Keyword(s):

Vomeronasal System ◽

Foraging Mode ◽

Gekko Gecko ◽

Leopard Gecko ◽

Prey Chemicals ◽

Chemical Discrimination ◽

Tokay Gecko ◽

Tongue Flicking ◽

Ambush Foraging ◽

Tongue Flicks

AbstractPoststrike elevation in tongue-flicking rate (PETF) and strike-induced chemosensory searching (SICS) were assessed experimentally in two species of gekkonoid lizards belonging to families differing in foraging mode. PETF is an increase in rate of lingual protrusions after a prey item has been bitten and escapes or is removed from the mouth of a squamate reptile, whereas SICS is PETF combined with locomotory searching behavior. Eublepharis mucularius, the leopard gecko, is an actively, albeit slowly, foraging eublepharid. This species exhibited PETF for a duration of about five minutes based on total lingual protrusions. Labial-licks were initially much more frequent than tongue-flicks. A substantial increase in movement occurred during minutes 5-8, hinting that SICS might be present, but was not quite significant. SICS is likely present, as in other actively foraging lizards, but was not conclusively demonstrated. Handling the lizards induced increased locomotion in both the experimental condition and a control condition, presumably accounting for the apparent delay in onset of increased movement. The tokay gecko, Gekko gecko, a gekkonid ambush forager, performed no tongue-flicks, but exhibited PETF based on labial-licks during the first minute. SICS was absent. These findings support the hypothesis that SICS is absent in ambush foraging lizards, which do not use the lingual-vomeronasal system to search for prey. They are suggestive, but equivocal regarding the hypothesis that SICS is present in actively foraging lizards that exhibit lingually mediated prey chemical discrimination. The finding of PETF in G. gecko suggests that this species and several iguanians previously found to increase rates of labial-licking after biting prey may be able to detect prey chemicals.

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Does foraging mode affect metabolic responses to feeding? A study of pygopodid lizards

Current Zoology ◽

10.1093/czoolo/59.5.618 ◽

2013 ◽

Vol 59 (5) ◽

pp. 618-625 ◽

Cited By ~ 3

Author(s):

Michael Wall ◽

Michael B. Thompson ◽

Richard Shine

Keyword(s):

Specific Dynamic Action ◽

Metabolic Responses ◽

Metabolic Rates ◽

Energetic Costs ◽

Foraging Mode ◽

Organismal Biology ◽

Lower Standard ◽

The Common ◽

Active Forager ◽

Ambush Foraging

Abstract Foraging mode (ambush vs. active) profoundly affects many aspects of organismal biology, including metabolic rates and their relationship with food intake. Previous studies on snakes suggest that ambushers tend to have lower standard metabolic rates (SMR) and higher energetic costs of digestion and assimilation of prey (specific dynamic action, or SDA) than do active foragers. However, phylogenetic considerations may be at least partly responsible for such patterns, as foraging mode is strongly conserved evolutionarily and most SDA studies have focused on species from only two lineages of ambush foragers (pythonid and viperid snakes) and one lineage of active foragers (colubrid snakes). We sought to deconfound the effects of phylogeny and foraging mode, investigating SMR and SDA in two closely related pygopodid lizards, the common scaly-foot Pygopus lepidopodus (active forager) and Burton’s legless lizard Lialis burtonis (ambush forager). Consistent with the pattern seen in snakes, L. burtonis exhibits a significantly lower SMR and a higher SDA than does P. lepidopodus. The magnitude of SDA in L. burtonis is comparable to that of some pythons and vipers, providing yet more evidence for the remarkable convergence between this species and ambush-foraging snakes.

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