Q: What do I need to know about snapping turtles if I keep chickens?
Chelydra serpentina or Macrochelys temminckii
Snapping turtles are large freshwater turtles . Common snapping turtles weight up to 75 pounds, but generally average around 35 pounds for an adult. Alligator snapping turtles have weighed up to 249 pounds incaptivity, but in the wild *only* get to be as large as 175 pounds or so. Still giant!
Found in eastern and southeastern North America
These are uncommon predators of chickens, although they may pose problems for you if you have snapping turtles in your area. Females especially are known to travel relatively far from their homes in ponds, streams, swampy areas and estuaries. Snapping turtles can eat baby chicks and small birds, and although adult chickens are too large for most snappers to consider "lunch," the largest may indeed want your favorite hens! Still if you have such a dragon near you, you are likely to know about it already. Even small snapping turtles are are notoriously grumpy on land, and may seriously injure the feet and legs of adult birds who get too near. One snap, even from a small snapper, can remove your finger, or a chicken's toes or leg--be careful! However, this is a merely defense mechanism, since they are so awkward on land. If encountered in or near water, these reptiles are shy, and normally just swim away.
Protecting Your Flock
Although they can dig, snapping turtles won't likely dig to get into your coop. They usually only dig in sand to lay their eggs (or down into mud in shallow areas to cover themselves), and not to find a way into your chicken run. To protect your birds from snapping turtles, a simple sturdy fence will usually do. Snapping turtles don't climb or jump, and won't typically hunt your chickens at all. They don't really have a method of getting into a secured coop. They will only be opportunistic predators, meaning that if they happen to come across a chicken while they're on their way somewhere else, they may take a snap, because who doesn't like a chicken dinner?
Remember, for snapping turtles, hunting normally consists of waiting for something unwary to wander near enough to be snapped up. (The snap, though, is very fast indeed!) Alligator snapping turtles found in the Southern US even have a worm-like "lure" on the tips of their tongues, and a camouflaged interior to their mouths. With the worm-like bait, they wait partially submerged and lure fish to swim right into their mouths, and eat them with a swift and powerful snap! Unless you have submarine chickens, this is just not going to be a problem.