Behavior

Feeding

Five-lined skinks consume a large variety of small vertebrates and invertebrates. Active and diurnal the skink subsists on mainly a diet of anything from "insects and earthworms to spiders and millipedes". In addition, larger adult skinks are known to eat "other lizards, small frogs, and young nestling mammals like mice. This eclectic diet has allowed the five-lined skink to be very successful in spreading itself through out the U.S. and Canada (Tyning 1990).

Habitat

Five-lined skinks are commonly found in moist, humid forests. They are usually found "on the ground, under stones, inpiles of leaves [and] in rotten logs". On sunny days they can often be seen basking in spots exposed to sunlight. They do not normally remain in one place for very long however, and nervously change location frequently. Individuals usually are found under cover, rather than emerging on cool days. Five-lined skinks "seldom climb trees" unlike the E. laticeps and E. inexpectatus (Tyning 1990; Smith 1971)

Territorial Behavior

Five-lined skinks are fairly sedentary animals, living within a small area for most of their lives. The home range of the skink includes locations for "basking, hiding, feeding, and nesting". These home ranges can overlap, and often many skinks may share something like a pile of rocks on which to bask. Five-lined skinks are also territorial animals however, particularly during breeding season. Male skinks will claim territories several yards in diameter, and take responsibility to both protect that territory and attract mates in the territory to breed. In examining another skink, various visual displays, aggressive actions and tongue-flicking behaviors may be employed. For example, a male may "rub his cloaca on the substrate and then rush at another lizard with his mouth wide open". The other lizard can either return the behavior, meaning a fight over the territory ensues, or can run away and leave the aggressor's territory. In this case, the aggressor often will chase the other individual for a few feet before returning to his territory (Tyning 1990).

Pheromones

Several experiments have been performed regarding the reaction of the five-lined skink to various pheromones. Pheromones are various chemicals released by the body in the attempt to create a response of some sort in other individuals (mostly of the same species). Studies have concluded that five-lined skinks do in fact respond to conspecific pheromones, but in general don't respond to interspecific pheromones. Flicking its tongue in and out regularly and bobbing its head to press its nose to the substrate allows the skink to pick up these chemical signals left by other individuals. Five-lined skinks were found to be attracted to the odors left by their own species. This may play a role in the winter hibernation as many times skinks have been found in together in small groups in underground burrows in preparation for winter. By following the odors left by another individual, this type of congregation is possible (Duvall, Hershowitz, Trupiano-Duvall 1980).

Courtship and Mating

Courtship behaviors begin at differing times depending on climate. Immediately following winter, five-lined skinks emerge from their winter hibernation spots underground and begin courtship behaviors. In general in the South this begins earlier because of the warmer climate, beginning late winter. In the North, courtship begins around April or May. Five-lined skinks don't engage in extensive courtship procedures. Male individuals "actively investigate any other skink that comes close enough". When the male approaches a female, she either retreats and leaving the male's territory, or remains and allows him to continue courting her. Regular behavior includes "head-bobbing, chin-rubbing, and scratching" before the male brings his body alongside the female's. At this point, the female points her snout down to the ground and the male grasps her neck in his jaws. He wraps his tail around hers and either he lifts her tail or she lifts it of her own accord. Copulation occurs in this position, lasting up to ten minutes after which the female leaves the male's territory (Tyning 1990).

Eggs and Brooding Behavior

Unlike most other skinks, those of the genus Eumeces exhibit egg-laying behavior. About a month after mating, the female five-lined skink builds her nest and deposits her eggs. Normal egg-laying sites include in rotting logs and stumps, beneath rocks and boards, in the litter covering the forest floor, and in moist soil. The nest is formed when the female scrapes away debris with her feet, or when a female enlarges an indentation in the substrate with enlarged movements of her body. Up to eighteen eggs can be deposited at once, and the female takes a protective position curled up around them. This egg-brooding behavior is exhibited in only a few other genuses of lizards. Extensive study has been done on the behavior revealing that the female periodically rolls each of her eggs. In addition, the importance of the close aggregation and care for her eggs has been revealed in experiments where the eggs of an individual was scattered and the individual was shown to make considerable efforts to bring the eggs back together. Identifying her own eggs with the tip of her tongue, the female five-lined skink is able to recognize her eggs even though they have been relocated to a different nesting site. Despite this care however, as soon as the young have hatched, the female show little or no interest in the young. The eggs themselves are "creamy white" and about half an inch long and three-eighths of an inch wide. The eggs swell over the course of development and are about three-quarters of an inch long and half an inch wide just before hatching. The time the female deposits the eggs is variable depending on the weather conditions. In the southern U.S. where the winter is shorter, mating occurs in late winter and eggs can be laid as early as April or May. In the North however, mating in general doesn't occur until April or May and so eggs aren't laid until as late as mid-July. There are also noticeable trends toward a reduction in clutch size as the species moves northward (Tyning 1990; Smith 1971)

Function of Tail

The tail serves as a last resort protection device for the skink against predators. Normally very easily frightened when approached, the five-lined skink relies on little other than its speed to escape prey. In case of capture however, the skink readily loses a large part of its tail when grasped. More so than in other types of lizards, this lost tail "thrashes violently about for many minutes". The idea behind this defense tactic is to confuse the predator and attract it's attention enough to allow the captured skink to escape and scurry away. The bright blue coloration of the juvenile tail may function to enhance the attractiveness of the tail. In addition, the length of the tail being similar to that of the body directs the predator even more to attack the non-vital tail instead of the individual. Because of the arrangement of vertebrae, muscles and blood vessels in the tail, healing is instantaneous and little blood is lost before the wound is healed and a new tail begun growing. All this makes this last defense mechanism efficient and low in cost to the animal (Tyning 1990).


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