Wednesday, April 29, 2009

Turtles....On the Road Again

I originally wrote this column last spring but plan on revisiting it annually this time of year.

It’s spring now and the amphibians and reptiles have awakened from their winter inactivity and are seeking out food to eat and sunny basking spots to warm themselves. Last night I came home to find a Fowler’s toad sitting by my front door, he was waiting for an opportunity to eat one of the hapless moths that had been attracted to my porch light. Over the last few weeks I’ve been serenaded by male toads singing their high-pitched trilling calls from the pond in front of my condo. They do so to attract females. Recently, the spring peepers have ceased calling, this species typically breeds early in the season and they have likely completed the bulk of their breeding. In turn, other species have begun. Last night was the first time I’ve heard a leopard frog this year, there was a single male calling out his chortling-like call. I expect to hear more in the coming weeks.

Another group of species that is increasingly active this time of year are turtles. Surrounding Auburn, the species you’re most likely to see are yellow-bellied sliders . They’re often floating just below the surface of the water with just their heads poking out. Although they’re closely associated with aquatic habitats, these turtles need to get out of the water for several reasons, primarily to lay eggs.

Over the next month or so, you’re likely to see turtles on the road as the females haul themselves out of the water and look for a suitable site to nest. The vast majority of freshwater turtles that people encounter crossing roads are females full of eggs or females returning to their wetland after nesting. There are also terrestrial species, such as box turtles, that encounter roads during part of their daily travels. As you might expect, these are dangerous journeys for turtles.

These animals are frequently found on roads killed by cars. Only recently, however, have researchers determined that the effects of individual turtles killed on the road are having significant effects on local populations. It all relates to the natural strategy that most turtles have adopted.

Turtles have a life history strategy that includes producing many eggs and young turtles. They have to produce many young because they are frequently eaten by predators. Contrast this with the strategy a deer or bear might employ, these species only produce a couple young each year, but these young have a relatively high chance of surviving until adulthood. Turtles, on the other hand, have a very slim chance of reaching maturity. However, once they have reached their maximum size, their tough shell allows them to escape predation from most natural predators. Since it is so rare that a young turtle becomes an adult, these mature individuals are valuable to a population’s persistence.

Although a turtle’s shell allows it sufficient protection from most natural predators, they are no match for an automobile. Turtle mortality due to cars has now been determined to change the sex ratio in neighboring populations. In areas with high road densities, freshwater turtle populations have many more adult males than they do females because the latter are killed on roads in greater numbers. This reduction in the number of breeding females has dangerous implications, it is unlikely that these populations can respond to these changes fast enough to rebound.

In response, there have been increasing attempts to making roads more compatible with wildlife. Outside Tallahassee, Florida, plans are in development to integrate a culvert system under a road that intersects Lake Jackson, a site of high turtle mortality. A similar system was incorporated into Payne’s Prairie State Park outside of Gainesville, Florida. Did you know that the Alabama state reptile is the Alabama red-bellied turtle? This turtle is an endangered species and is found only in Alabama. Road mortality of this species poses a significant problem and the Alabama Department of Transportation recently installed a fence along the Mobile causeway to protect females hauling themselves onto land to nest.

After reading this, you may feel inclined to help a turtle across the road the next time you see one (I hope so, at least). However, it is of the utmost importance that you consider your own safety first. Do not endanger yourself on roads. That said, a turtle should placed on the side on the road in the direction it was heading. They know where they want to go and will just try to cross the road again if you put it on the wrong side. I typically place turtles just off the road right-of-way, at the edge of the mowed vegetation (if the area isn’t developed). Although you may be tempted to bring the turtle home or relocate it to a different area, keep in mind that turtles are accustomed to their specific habitat. Relocated turtles often become disoriented and may be more susceptible to predators in the unfamiliar area.

Snapping turtles represent a unique dilemma. Seldom is an animal so uncooperative when one attempts to help them. You may find it useful to usher the turtle into a box for convenient transfer across the road. Otherwise, you can hold onto the turtle’s shell (near the back) or its back legs and pick it up this way. Keep in mind that a snapping turtle has an extremely long neck. Some find it most efficient to simply grab its back legs and carry it across the road (keep it away from your body). Picking up a snapping turtle by the tail should only be used as a last resort as this may injure the turtle’s spine. I’ve handled over 200 snapping turtles and have never been bitten, use caution and you will be fine.

I initially wondered whether the timing was right for this column, but within the last week I found a mud turtle crossing the street off of Longleaf Drive, a large river cooter in the road in southwest Georgia, and a friend showed me a box turtle that had been hit by a car and suffered some damage to the rear of the shell. It was destined for a wildlife rehabilitation center.

Photo courtesy Matt Aresco


Carol said...

I've stopped and helped many a turtle cross the road. One so large I could hardly pick it up.

David Steen said...

I'm glad you do Carol, but be careful out there.

Great site!


aristide said...

da noi non ci sono pero' belle