The slender glass lizard (Ophisaurus attenuatus) is a legless lizard in the glass lizard subfamily (Anguinae). The species is endemic to the United States. Two subspecies are recognized. The lizard was originally believed to be a subspecies of the eastern glass lizard (Ophisaurus ventralis). Their name comes from their easily broken tail which they can break off themselves without ever being touched. It is difficult to find a specimen with an undamaged tail. The lizard eats a variety of insects and small animals, including smaller lizards. Snakes and other animals are known to prey on the species. Humans have a part in destroying their environment and killing their food supply with insecticides. The lizard is considered to be a least-concern species according to the International Union for Conservation of Nature (IUCN), though it is vulnerable in Iowa and endangered in Wisconsin. The streamlined, legless species is often confused with snakes. Glass Lizards, however, differ from snakes as they possess a moveable eyelid, which is absent in snakes. Another way to distinguish glass lizards from snakes is the presence of an external ear opening, which are absent in snakes.
Taxonomy
The species was originally believed by American herpetologist Edward Drinker Cope to be a subspecies of Ophisaurus ventralis in 1880 under the name Opheosaurus ventralis attenuatus. It was not until 1885 when the British herpetologist George Albert Boulenger recognized it to be its own species. However, Cope's belief influenced other herpetologists until 1949 when another American herpetologist Wilfred T. Neill expressed his belief that Boulenger was correct about it being a distinct species. The difference between this species with O. ventralis and other species in the genus is that the white spots on its dorsum are located on the posterior edges of its scales, with none of the spots being located mainly in middle of its scales. Another distinctive difference is that this species has 98 or more scales along its lateral fold. In the word Ophisaurus, orphis is Ancient Greek for serpent or reptile and saurus means lizard or reptile. The word attenuatus is Latin for "tapered, drawn out, thin".
The western slender glass lizard reaches an average of . It can be found in woods or dry rocky hillsides, in grass or the burrows of small mammals. The species can easily camouflage itself in tall grass because of its color.
- Eastern slender glass lizard, O. a. longicaudus
Description
thumb|Western slender glass lizard (Ophisaurus attenuatus attenuatus), Vernon County, Missouri (14 June 2019)
thumb|Eastern slender glass lizard (Ophisaurus attenuatus longicaudus), Gilchrist County, Florida (29 Mar 2021)
thumb|Western slender glass lizard (Ophisaurus attenuatus attenuatus), Colorado County, Texas (30 Mar 2018)
Slender glass lizards have yellow to brown bodies with six stripes and they have a middorsal stripe. White specks on the middle of the lizard's scales may sometimes form light stripes. O. attenuatus can attain a total length of to . The species is closely related to collared lizards. Its tail comprises two-thirds of its body length. Its scales are supported by an osteoderm which makes the body hard and stiff. The species has a pointed snout and a non-distinct head. Males and females are of similar size. Its markings may fade as an individual ages.
Unlike snakes, they have eyelids and ears. The body of a snake is more flexible than that of this species and have different shaped scales.
Behavior
Slender glass lizards are primarily diurnal and they can move fast. If captured, a specimen may thrash vigorously, causing part of the tail to fall off in one or more pieces. While a potential predator is distracted by the wiggling tail, the lizard quickly escapes. They are known to sleep in burrows borrowed from other animals and they will use those burrows to hibernate. The species is active during the day when the weather is cool, but is only active during dawn and dusk when the temperature is hot. The lizard hibernates from October until April or May.
When a predator breaks off part of its tail, the tail never completely grows back which causes its tail to become shorter each time that it is attacked. They are known as slender glass lizards because their tail can be broken easily. The species can snap off their tail without it being touched and the partial tail that regenerates is tan, but it does not have the pattern of the original tail.
Distribution
O. attenuatus is found in the midwestern and southeast United States, where it is endemic, in prairies, old fields, or open woodlands, often near water. The size of their food can be no larger than the size of their head. Primary threats include habitat loss and fragmentation stemming from human development. Insecticides also pose a threat to the lizard by eliminating their insect prey and potentially introducing toxins into their diet through the contaminated insects.
The Iowa Department of Natural Resources recommended steps to conserve the slender glass lizard which are to avoid burning grassland from April to October, to remove trees mechanically instead of using chemicals, and to limit insecticide use in areas where slender glass lizards are known to inhabit.