|Common Name:||Wood Turtle|
|Scientific Name:||Glyptemys insculpta|
|Genus:||Glyptemys - Giypt is Greek meaning "carved", emys is Greek meaning "turtle".|
|Species:||insculpta is derived from the Latin word insculptus which means "engraved". This refers to the engraved texture of the carapace.|
|Average Length:||5.5 - 8 in. (14 - 20 cm)|
|Virginia Record Length:||8.5 in. (21.6 cm)|
|Record length:||9.2 in. (23.4 cm)|
Virginia Wildlife Action Plan Rating Tier I - Critical Conservation Need - Faces an extremely high risk of extinction or extirpation. Populations of these species are at critically low levels, facing immediate threat(s), or occur within an extremely limited range. Intense and immediate management action is needed.
PHYSICAL DESCRIPTION: This turtle is medium sized, from 12.5-23 cm, with a keeled, sculptured carapace.In Virginia the max known carapace length is 216 mm and plastron length is 191mm. The broad, low carapace is rough and each large scute supports an irregular pyramid formed by a series of concentric growth ridges and grooves *2988*. The posteriorly widened carapace has strongly flared and serrated marginals, though this is often reduced and/or eliminated with wearing that acumulates with age. On the carapace there are five vertebral scutes, two parallel rows of four pleural scutes, and 12 marginal scutes on each side. Each of these is gray to brown, often with black and yellow lines radiating from the medial, prosterior area of the scute. The skin is some variation of orange (from yellow to red), depending upon age, sex, time of year, and the individual. The scales, including those on the head, are brown, gray, or black. Where the scales meet the skin on the posterior area of the head, the color changes from black to orange in a posterior direction *11675,10760,2988*. The bottom of the marginals and the bridge often have dark blotches along the seams. The plastron is yellow and hingeless and has a pattern of oblong dark blotches on each scute. It is usually as big or just slightly smaller than the carapace. The tail is long. The large head is black with a nonprojecting snout and a notched upper jaw *10760,2988*. Proportionately, the head of the male is larger than that of the female. Also, the male develops proportionately larger frontal claws than does the female. The male's enlarged claws are also recurved. These enlarged, recurved claws are used to clasp the female during pre-copulatory mating *11675*. The male has a long thick tail with the anal opening posterior to the carapacial margin, concave plastron with deeply notched posterior margin, prominent scales on anterior surface of forelimbs *2988*. Females lack the large scales on the forelimbs and the longer tail and their plastron is flat. During mating season a difference in coloration on the ventral sides of the limbs, chin, and neck is especially discernable: pale yellow for females and orange-red in males. Females tend to have somewhat smaller carapaces than males with populations in Frederick County averaging 179.8mm CL and 180.3mm PL for females as compared to 199.8mm CL and 179.3mm PL for males *10760*. Sexual dimorphism usually occurs across all populations. Both average and maximum female sizes are smaller than average and maximum male sizes *11675,11676*. The skin of the juvenile lacks any red or orange pigment and is grey to brown in color, instead *10760*. This seems to occur uniformly in hatchlings and one year olds. The start of the second year seems to be the time when they develop the more typical pigmentation of the adults, if they have grown sufficiently. However, at this time the pigmentation is still less distinct than that of the adults *11675*. The tail almost equals the very round carapace in length. The hatchlings of one Virginia clutch measured between 37-40 mm CL and 34-38 mm PL *11675,10760*. Wood turtles lack the bright orange patch on the side of the head found in the bog turtle *9286*.
REPRODUCTION: In Virginia, mating behavior occurs year-round with the greatest frequency of observations occurring shortly after wood turtles return to the streams in the fall. Since female wood turtles can store sperm, there need not be close timing between mating and nesting. Males usually aggressively initiate mating by chasing the female and then mountyer her carapace. When courtship is more parsimonious, the male and female approach each other slowly with the necks extended and heads held high. When the turtles are within 8 inches of touching each other they suddenly lower their heads and swing them from side to side, a ritualized behavior that may continue for as long as 2 hours. After mounting, the male then holds the shell of the female with all four feet; his foreclaws close around the front edge of her carapace and hind-claws clamp around the rar edge. He then proceeds to thump, bite, and rock the female. Kauffman (1992) reported that successful insemination in Clemmys insculpta, as indicated by copulatory ties, is preceded by gentle side to side shaking of the mounted pair. He observed that most episodes of clasping, biting, and thumping, with or without shaking, are not associated with insemination. Indeed, recent evidence suggests that different embryos within a single clutch may be fathered by different males *11675,11677,11169*. The nesting season extends from late May to early July with the greatest frequency of observed nesting in early June. Some females may forego nesting in some years, but normally lay one clutch per year. There is no evidence of multiple clutching within a year. Clutches of 7-14 eggs are most common. The eggs are deposited in a cavity in the ground dug by the female, then covered and left to be incubated by the sun's heat. Nests are most often excavated on sandy-gravel banks near the stream, but wood turtles are known to nest in fields, along roadsides, in gravel pits, and manure piles. The elliptical eggs are whitish, and have smooth, thin shells 40 mm long and 26 mm wide, on average. Incubation normally takes 70-80 days with known emergence dates in Virginia from July 30 to October 2 *11675,9286,10760,11613,2988,10990,1027*.
BEHAVIOR: Though not always, wood turtles are primarily solitary on land. They are often found together in small groups when they congregate in hibernacula, where mating may or may not occur. Also, they may be found together at an important feeding source, such as a fruiting tree *11675*. In general, a wood turtle's activity centers around the floodplain of the creek. This includes flooded forests, wet meadows, swamps, and riparian forests. However, there are individuals that consistently wander great distances (up to 3 km from a prior winter hibernaculum in Virginia) beginning in mid-May and continuing through late August or early September. It is also likely that most adult individuals roam up to 1 km from the home creek in search of optimal foraging habitat at some point during the summer. Likewise, it is not at all uncommon for females to meander several kilometers, quite curiously, in search of the right combination of weather, substrate, exposure, and microhabitat position for nesting. Some individuals appear year after year in the same place. In this sense, they exhibit a great deal of fidelity to an activity center, but roaming is a normal strategy for the species as a whole *11627,1027*. The eggs are deposited in a cavity in the ground dug by the female then covered and left to be hatched by the heat of the sun *1007*. Hibernation in wood turtles is complex. They seem to return to the creeks in the fall when nighttime air temperatures are consistently near freezing. While this case may be the norm at more northerly latitudes, it does not appear to be a consistent condition in Virginia. Therefore, wood turtles probably become increasingly less active after they enter the water from October through December. Pinder has observed this species active and breeding in December. In January and February they are primarily dormant with infrequent spells of brief activity, which may include mating behavior, and that appears to be positively correlated with solar radiation and air temperature. The frequency and duration of their activity seems to steadily increase in March until they begin to make brief, short-distance froays onto land in late March and early April *11675,11613*. It hibernates in the mud bottom of some waterway or in a hole in the bank *2988*. They may also hibernate in decaying vegetation of comparatively dry woods *1027*. They are fond of basking in the early morning. On dry summer months it often soaks in mud puddles *2988*. The normal annual activity period of northern wood turtles is April through November, but in Virginia some aquatic movements may occur in December and January. Both sexes wander on land until the autumn when they return to the aquatic hibernation sites. Daily activity is in the afternoon in the spring, morning in the summer, and then back to afternoon in the fall. They are diurnal. Although some may move overland several hundred meters while foraging or searching for nesting sites, most activity is restricted to home ranges of one to six acres. A radiotagged Virginia male moved 1.0 km in one day from his hibernaculum to his normal summer home range. They possess homing ability and some individuals have returned from distances of over 2 km. This species is omnivorous. Plant remains were found in 76%, and animal remains were found in 80% of the turtles examined in one study. Plant foods include filamentous algae, moss, fungi, grass, willow leaves, violets, strawberries, blueberries, rasberries and sorrel. Animal foods include a wide variety of insects and mollusks, earthworms, dead fish, tadpoles, newborn mice and other turtles' eggs. Scavenging occurs and carrion is consumed. This species is not territorial *9286,10760*.
ORIGIN: This turtle is native *10760*.
POPULATIONS PARAMETERS: They occupy home ranges 1-6 acres but may hibernate in a different site up to a Km away. They can live to be up to 40 years old and probably have low productivity *10760*. Population studies of this turtle in the Southern part of its range would be useful *10760*. The first phase of studies on the southern part of its range are nearing completion. Future monitoring to detect trends and/or stochastic events is necessary *11675*.
AQUATIC/TERRESTRIAL ASSOCIATIONS: They are associated with Clemmys guttata, G. muhlenbergii, Chrysemys picta, Terrapene carolina, Sternotherus odoratus, and Chelydra serpentina *2988*. Predators include skunks (eggs), largemouth bass (young), hawk and crow (adults) *2988*. They are sometimes infested with leeches *1007*.
References for Life History
*Click on a thumbnail for a larger version.
|Carapace||Plastron||Adult - Fairfax Co.||Four year old|
|Breeding Pair||Breeding Pair||Neonate
Verified in 10 Counties/Cities.