The present study examined for the first time whether a Morris water-maze can be used to explore compass and other orientation mechanisms in the ruin lizard Podarcis sicula. In the open field, during sunny days, lizards were individually trained to swim from the center of the water maze onto a hidden platform (the goal), positioned at the periphery of the maze in a single compass direction. The...

Bipedal locomotion by lizards has previously been considered to provide a locomotory advantage. We examined this premise for a group of quadrupedal Australian agamid lizards, which vary in the extent to which they will become bipedal. The percentage of strides that each species ran bipedally, recorded using high speed video cameras, was positively related to body size and the proximity of the b...

Komodo dragons, the world's largest lizard, dispatch their large ungulate prey by biting and tearing flesh. If a prey escapes, oral bacteria inoculated into the wound reputedly induce a sepsis that augments later prey capture by the same or other lizards. However, the ecological and evolutionary basis of sepsis in Komodo prey acquisition is controversial. Two models have been proposed. The "bac...

We examined whether western fence lizards Sceloporus occidentalis occurring in thermally divergent environments display differential responses to high temperature in locomotor performance and heat-shock protein (Hsp) expression. We measured maximum sprint speed in S. occidentalis from four populations at paired latitudes and elevations before and after exposure to an experimental heat treatment...

Horned lizards (Iguanidae, Phrynosomatinae, Phrynosoma) are morphologically specialized reptiles characterized by squat, tank-like bodies, short limbs, blunt snouts, spines and cranial horns, among other traits. They are unusual among lizards in the degree to which they specialize on a diet of ants, but exceptional in the number of pugnacious, highly venomous, stinging ants they consume, especi...

Resource subsidies from external habitats can enhance the performance or population density of local consumers, altering their effects on in situ prey. Indirect effects of subsidies may be either positive or negative depending on the behavior of the shared consumer. Here we document strong links between riverine insects, riparian lizards (Sceloporus occidentalis), and terrestrial invertebrates....

In geographically widespread ectotherms, variation in life history phenotypes may be caused by differences in maintenance metabolism of individuals. I estimated daily and annual maintenance metabolism of eastern fence lizards, Sceloporus undulatus, from two populations with markedly different life histories; lizards in South Carolina grow faster, mature earlier, and have greater annual reproduc...

Quantitative abilities have been reported in many animal species. Two main methods have been extensively used: spontaneous choice tests and training procedures. A recent study showed that ruin lizards are capable of spontaneously discriminating between the surface area of two food items of different size, but failed when food was presented in sets of discrete items differing in number. In the p...

We evaluated the impact of marine materials on the diet and abundance of arthropodivorous lizards inhabiting islands and the coast of the Gulf of California. Here, marine materials are brought onto land by seabirds and by tidal action, and both subsidy pathways cause arthropod abundance to increase. We evaluated Uta stansburiana (side-blotched lizard) diets in three habitats defined by having: ...

Exotic predators have driven the extinction of many island species. We examined impacts of feral cats on the abundance and anti-predator behaviours of Aegean wall lizards in the Cyclades (Greece), where cats were introduced thousands of years ago. We compared populations with high and low cat density on Naxos Island and populations on surrounding islets with no cats. Cats reduced wall lizard po...