Stejneger's Grass Lizard is an endemic species of Taiwan , and was thought to be identical to the Chinese grass lizards of Mainland China . In fact, these two lizards are quite different; on average, the Chinese grass lizard is larger ( 11mm longer), has less scales (6-8 on Stejneger's Grass Lizard and 4-6 on the Chinese grass lizard) and more eggs (3-4 compared to Formosan grass lizard's two eggs). Stejneger's Grass Lizard was first discovered by an American, Van Denburgh, in 1912 in Taiwan . The holotype specimen is now stored at the California Academy of Sciences. This type of lizard is often mistaken for another grass lizard, the Formosan Grass lizard, which is similar in morphology and appearance. The easiest way to indentify one from another is to count the groin openings, located at the hind limb regions. Stejneger's Grass Lizard has 1 pair (1 on both sides) and the Formosan grass lizard has two pairs (two on each side). The body length of a Stejneger's Grass Lizard measures between 31.0 to 54.5mm long, and averages about 49.5mm ( Lin and Cheng, 1990). They are distributed all across Taiwan and can be found on plains, hill tops 500m above sea level, and on islands like Penghu and Lamay.

Diet

As the first morning sun light breaks through the clouds, these lizards leisurely drink from dew drops on the leaves of White Lead trees, and forage as they go about their business. They are migrant feeders, loitering and taking precaution while feeding in their activity zones. Lizards that feed in such fashion often have excellent vision or a sense of smell, and can obtain food easily. However, they are also more susceptible to predation during their feeding. A Stejneger's grass lizard's main diet includes insects like grasshoppers, beetles and woodlice. The liver mass of a female lizard increases from January and reaches its maximum in July, then gradually decreases to its lowest in December. The adipose tissue drops to the lowest during March and April, and increases to its maximum in November.

Color

S tejneger's grass lizards are usually colored olive brown or light brown, and have a yellowish brown stripe along their lateral sides. These color patterns camouflage them from predators when they hide in fallen leaf piles. However, some individuals are colored green and are more suitable to thrive in grassy environments. These lizards are poikilotherms, their body temperature is regulated by ambient air temperature; therefore they are more active on bright sunny days. During summer and spring times, these lizards are at their highest activity levels, mating and reproducing. After October, the temperature drops, and they disappear from the wild.

Habitat

Stejneger's grass lizards favor habitats like drought fields, grass fields, flower beds and the forest. They can be easily found on terminal leaves on small branches. The White Lead trees on Penghu Island grow in convoluted shapes, intertwining with that of the thorny nettle plants, which make it difficult for larger predators like snakes to navigate freely. These are also favored hiding places of Stejneger's grass lizards. They are social animals, and territorial behavior has not yet been observed.

Activity

These lizards are diurnal, fond of scurrying about in tree branches or weed piles. They are thin and slender and can dart up trees quickly, navigating between branches with ease. Unless threatened, these lizards move about leisurely, and will likely pose for photography – if you observe them quietly.

Breeding

The smallest adult individual of a Stejneger's grass lizard measures about 4cm from snout to anus. The spawning periods are between March and August, occurring twice a year. They are multiple-nested types (spawning twice or above per year), lay 2 to 3 eggs at a time, and the eggs average 0.6 x 1.0 cm in sizes. The incubation period is 32 days on average. The newly hatched infants measure about 2.1cm long. The males are fertile all year around except the months of August to October ( Lin and Cheng, 1990).