Monday, 24 October 2011

Our North-Eastern Turtles

Our North-Eastern Turtles

A. Hyatt Verrill

Popular Science; Jul 1, 1899; illustrated by the author, researched by Alan Schenker, digitized by Doug Frizzle October 2011

Among the turtles of our north-eastern states, there are, strictly speaking, no land turtles. Our so-called land-tortoises, such as the box-turtles, belong to the family Emydidae or pond-turtles, many species of which are entirely terrestrial, while others spend their lives partly on land and partly in water, still others being strictly aquatic. The family Emydidae is divided into seven genera, the family Cinosternidae into two genera, the family Chelydidae into two genera, and the fourth and last family, Trionychidae, into two genera.

Of these four families, no representation of the Trionychidae or "soft-shelled turtles," occur in our eastern states, and the family can consequently be omitted for the present. Still another family, Testudinidae, is represented in North America by a single species and genus, the "gopher" turtle of the southern states and the only true land turtle of the United States.

The first genus, Cistudo, family Emydidae, is represented in the north-eastern and middle states by the common "box turtle," an abundant and well known species. This creature is widely distributed and varies much in color. As a general rule the shell is black or dusky, variegated with orange or yellow in spots, blotches or radiating lines on each plate. The lower shell is usually flesh-color marked with dusky, but is frequently entirely black. The box turtle is most readily found in early spring in rather damp woods, several individuals often being seen together. It is a noteworthy fact that nearly all specimens of this species are very nearly of a size, small individuals being extremely rare and very small or newly hatched specimens almost unknown.

The food of the box-turtle consists of grass and other vegetables, and insects. These turtles are popularly supposed to attain a great age, the belief being mainly founded on the fact that initials and dates of forty or fifty, or even five hundred years ago are found carved on the plastron of box-turtles. This can hardly be taken as reliable evidence of the animal's age, however, as I once secured a turtle with the inscription "C. C. 1492," cut deeply in his shell. All the tortoises, however, mature very slowly, and a full grown box-turtle may not improbably have reached an age of half a century, or even more.

Our next genus of this family is Chelopus or the wood-turtles, containing two species only, one of which, the "sculptured-turtle," is found in the eastern states. This species is an amphibious creature, living on land the greater portion of the time, but taking readily to the water, and during dry weather living in ditches and shallow pools. It is readily identified by the carinated shell and plain brown plates, which are beautifully marked or sculptured with concentric striations and radiating lines. The eggs of this species are broadly elliptical, pure white and with rather a hard shell. They are deposited late in May or early June in sandy spots near lakes, ponds or streams, and the newly hatched young immediately enter the water.

The third genus of this family, Nanemys, contains a single species, the common "spotted mud turtle." This species is entirely black above, more or less speckled with yellow or orange. The lower shell is yellow or pink, blotched with black. The spotted turtle inhabits streams and ponds, and is particularly partial to swift running brooks. It is comparatively sluggish and easily captured and kept alive, frequently becoming so tame as to take food from the hand. The eggs are oval and very frail, the shell being a mere membrane through which the yolk can be readily seen. They are laid in early spring near ponds or brooks, and often are entirely exposed to view, scarcely any attempt at covering being made.

The fifth genus, Chrysemys, also contains but one species, the common "mud turtle" or "painted" turtle. This is probably our most common as well as handsomest species, and is found in nearly every pond, lake or ditch in the United States. In color this turtle is greenish black, each plate with a paler, often yellow, margin. The marginal plates of the carapace are streaked and blotched with vivid red, and the head, feet and tail are striped with lemon-yellow and red. Although this is generally considered a strictly aquatic species, yet during the breeding season they frequently wander long distances from water. On one occasion I found a specimen on a mountain top, fully a mile from the nearest streams, and at a height of over 400 feet above the surrounding country. The painted turtle is rather savage when captured, biting and snapping in quite a ferocious manner. The eggs are long and slender, with a translucent white shell, and are hidden in sand, frequently some distance from the water.

The sixth genus, Malacoclemmys, or "marsh turtle," contains three or four species, only one of which, the "salt-marsh" turtle or "diamond-back," is found in the east. This species, famous for its edible qualities, is confined to the marshes along the sea-coast from New England to Texas. It is a large and handsome species, dark olive in color, each plate ornamented with concentric black stripes. During the cold weather these turtles hibernate in the mud of creeks and rivers; it is at this time they are generally hunted for the market, the hunters locating them by prodding the mud with sticks or iron rods. The seventh and last genus of this family contains some half-dozen species known as "terrapins," only one of which occasionally occurs in our northeastern states. This is Pseudemys hieroglyphica, the "hieroglyphic" or "map" turtle. This is in most places a rare species. The shell is very smooth, olive brown in color, marked with broad, reticulated yellow lines. The species is readily known by the extremely small head, which lends a rather disagreeable snake-like appearance to its owner.

The two genera of Cinosternidae are known as Cinosternum and Aromochelys, —the first containing one and the second two species. C. pennsylvanicum is a peculiar turtle found commonly in the south, but rare or casual as far north as New York. This turtle somewhat resembles a small box-turtle, the lower shell being hinged and movable. The color is dusky, and the head and neck striped and dotted with yellow. It is aquatic in its habits. The members of the genus Aromochelys are commonly known as "musk turtles" or by the more common and less elegant name of "stink pots." The common eastern species is an abundant inhabitant of muddy stagnant ponds and swamps, and is easily distinguished from any other eastern species by its strong and offensive odor. The shell is slightly keeled but otherwise smooth, dusky or blackish, rarely spotted. The head is very large, with a yellow stripe running from the nose above the eye down the neck, with another below the eye. The jaws are strong and powerful, and capable of inflicting a severe wound. The eggs are rather round than oval, and are laid close to the water's edge.

Of the two genera comprising the family Chelididae, the first Chelydea, containing one species, the common "snapping-turtle," is the only one represented in the eastern states. This large and well-known turtle is noted for its ferocity, strength and powerful jaws. A good-sized specimen can readily bite a broom handle in two, and they are doubtless, for their size, the most savage and strongest of reptiles. Specimens occasionally reach an immense size, sometimes attaining a length of 3½ to 4 feet and weighing 100 pounds. The lower shell is very peculiar, being almost cartilaginous, and very small and cross-shaped. The head is large, the jaws hooked, the tail and neck long, and stout, and the tail provided with a crest of horny tubercles or scales, and with the legs and head cannot, as is the case with most turtles, be withdrawn into the shell. The eggs of this species are spherical in shape and white in color. They are deposited in sandy soil on the banks of ponds or rivers and perhaps are more frequently observed than the eggs of any other turtle. The young when first hatched are provided with a stout horn on the tip of the nose (apparently used in breaking the egg-shell), and the tail is turned upwards at right angles to the body giving them an exceedingly comical appearance.

No comments:

Blog Archive

Countries we have visited