Natural Wonders

The Common Snapping Turtle

by Mike Roberts, Contributing Columnist

 

The Common Snapping Turtle (Chelydra serpentina)  

Appropriately named for its defensive tactics, the common snapping turtle has long been maligned by well-meaning humans, mainly because of unfounded fear and generations of folklore. Revealing this semi-aquatic reptile’s seasonal behavior is unlikely to reverse such mindsets, but for the sake of understanding, let’s try!  

As a kid who loved to fish, I distinctly remember two things my grandfather told me about snapping turtles. First, if one latches onto your finger, the animal will not release its vise-like grip until thunder sounds. That threat was enough to make me keep my hands well out of striking distance of the occasional ill-tempered turtle that inhaled a minnow or worm intended for bass and bluegills.

The other information my grandfather offered about snapping turtles was that they were good to eat. He declared they had seven flavors of meat in their bodies – one of which even tasted like chicken and was best prepared as a soup dish. Growing up on a farm, however, I saw no need to chance pain because of some reptile’s nasty disposition about becoming table fare, especially with all the chickens running around our barnyard. 

Then one warm, spring evening, upon angrily examining a stringer of mangled, largemouth-bass carcasses, I began blaming snapping turtles for the disappearance of wildlife from the neighborhood ponds – especially fish and ducklings. As a kid, I failed to consider that foxes, raccoons, minks, river otters, water snakes, great blue herons, red-tailed hawks, great horned owls and ospreys were taking their fair share, too. Even as a budding naturalist, it took me half a lifetime to develop a personal appreciation for the snapping turtle’s seemingly sinister role in helping to balance the natural environment.

Perhaps the most notable part of the common snapping turtle’s morphology, like all 260 or so species of turtles around the world, is the shell. This hard, outer covering is divided into two distinctive parts – the upper section, called the carapace, and the lower section, called the plastron. In most species, both sections are fused together, but those of the snapping turtle are held together by ligaments. The animal’s vertebrae and ribs are fused with the carapace, which is comprised of bones covered with unique plates, called scutes. These epidermal plates are shed and replaced as the animal grows. The majority of turtles can retract their head, neck, legs and tail within the safety of the shell, but snapping turtles cannot. Ironically, they have the smallest plastron of any species.

With the exception of humans, snapping turtles have few predators. When on land, any vulnerability is offset by maintaining a head-on, defensive posture, lightning-quick head lunges, loud hissing, and repeated attempts to bite the assailant with its sharp, hooked, keratinous beak. Such behavior has served to label them with the reputation of being fierce and aggressive creatures. Still, when in water (where they spend the majority of their lives), snapping turtles flee at the first sight of humans.

Like all reptiles, snapping turtles are ectothermic in nature. In other words, as a cold-blooded animal, they must control their internal temperature by sources outside the body. Seldom do they crawl out of water onto logs or rocks to bask – the manner of thermoregulation preferred by many turtle species. When basking, snapping turtles either lie motionless in shallow water or swim to the surface of deeper water and, while floating, expose the entire top surface of the carapace. Basking raises the turtle’s internal body temperature, which aids in food digestion. Direct sunlight also helps to reduce the growth of algae on the shell, and some biologists believe it necessary to prevent shell diseases.

During spring, the male snapping turtles (distinguished by longer tails and larger bodies), move from pond to pond searching out receptive females. Sometimes exceeding 40 pounds, the warriors battle over territorial and breeding rights, which creates quite a spectacle. Locked in each other’s muscular, four-legged grip, the combatants roll about in the water and mud for hours, all the while trying to kick, scratch and bite their way to an eventual snapping turtle honeymoon.

With the warming temperatures of late May and June, the pregnant females leave the security of the ponds and slow-moving streams to seek out suitable nesting sites. These sites vary from open fields to pond dams, roadways and dirt banks and usually are located away from water. Once an area has been selected, the expectant mother digs several holes, but deposits the spherical white eggs (typically 20 or more) in only one of the cavities. This curious behavior is likely to confuse predators that relish fresh turtle eggs. After sealing the cavity opening with soil, the female heads back to the water. Marauding skunks and raccoons consume the majority of the eggs within a day or two of having been laid. Still, in compliance with the laws of nature, a percentage of the eggs survives predation to assure continuation of the species.

Like some other reptiles, particularly alligators and crocodiles, incubation temperature dictates the sex of the snapping turtle hatchlings. Yet, because of all the variables associated with the annual

egg-laying process and the depth of the nest cavity, each nest is likely to produce both males and females within approximately three months of incubation by the warmth of the summer sun.

Snapping turtles feed during the day and at nighttime on a diet of both aquatic vegetation and animal material. As scavengers, they locate dead fish and other animals in the water by utilizing the combined senses of sight and smell. Being opportunistic predators, these turtles are capable of catching small vertebrates that share the same habitat – including fish and ducklings. The life expectancy of snapping turtles can exceed 50 years. In the northern latitudes of their range, they spend the winter months submerged and buried in mud, whereas further south they remain active throughout the year.

Although not nearly as impressive as the legendary alligator snapper that resides in the swamps of the Deep South , the common snapping turtle has adapted to increased human populations, which is understandable; the species has survived environmental change for millions of years, perhaps even watching the coming and going of dinosaurs.

Soup, anyone?

Wild Bird Profile: Red-winged Blackbird

Agelaius phoeniceus

After a full winter’s absence of birdsong, a favorite anticipation of birdwatchers is the spirit-lifting, migratory homecoming of male red-winged blackbirds to the lifeless reeds and cattail stalks of their springtime habitat.

More often than not, however, frigid temperatures and snowflakes greet these flocks of returning travelers. Still, with increasing daylight hours and eventual warming temperatures, the birds begin staking out individual territories, flaring scarlet epaulets, and filling the air with their coarse, gurgling songs of “konk-la-ree, konk-la-reee.” Upon the delayed arrival of the females (easily distinguished by dark-brown, topside attire, and heavily streaked, tan breast feathers), the “pomp and ceremony” of the male’s breeding activity greatly intensifies.

True to their family’s Latin namesake, troupial (TROOP-ih-al), meaning the habit of gathering in large flocks, red-winged blackbirds are one of the most abundant songbirds in North America . Often mixing with grackles and numbering in the millions, these migrating masses of birdlife occasionally confuse meteorologists by showing up as clouds moving across the radar screen.

As further evidence of subtle environmental changes occurring across our planet, the blackbird, that historically nested in the shrubs and tall vegetation of open marshes and along the edges of ponds, now also selects nest sites far from water, even in open hayfields. Nesting usually begins in April. The female incubates her four blue eggs for approximately 12 days. Occasionally polygamous, the male red-winged blackbird aggressively defends the eggs and young from predators, especially crows and hawks that venture into private airspace.  

 

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