WILDER SIDE OF OAKLAND COUNTY
Great Blue Herons, northern water snakes, snapping turtles, Great Egrets and American bullfrogs all share a common trait. They are five of the most commonly seen ambush predators of Oakland County wetlands. Ambush predators are masters of stealth and patience, remaining motionless as they wait for potential prey to come within pouncing or striking range. It’s a very effective strategy for hunting. For by staying motionless, they are less exposed to their own predators. The lying-in-wait strategy gives them the advantage of a surprise attack without the need for an energy consuming and perhaps risky chase. Now, at the dawn of summer, thick carpets of duckweed coat the shallow wetlands and the scene is set for the next lightning-fast strike.
The American bullfrog is the largest frog of Oakland County and a well camouflaged ambush predator with the patience and ability to stay absolutely motionless. While partially coated with duckweed amidst a sea of greenery, they wait for smaller unsuspecting creatures to swim, slither, fly or flutter within reach. They are voracious still hunters with a diet that includes dragonflies and other insects, snakes, small birds, rodents, low-flying bats and even other frogs. The smallest motion on the part of a bullfrog, even a movement that creates the slightest of ripples (before the pounce and gulp maneuver), can turn the tides of predator or prey. More than few bullfrogs fall prey to Great Blue herons and snapping turtles in the Oakland County Parks, while down in the American south, young alligators find bullfrogs an easy mouthful of meat.
The Great Egret and Great Blue Heron are skilled at finding just the right location in the shallows of a wetland to stand motionlessly and wait, and wait, and wait. When a small fish, baby muskrat, frog or snake comes into range, the long neck of these amazing birds moves ever so slightly to prepare for the strike. The beak is used to perform a stab-and-grab maneuver and the prey goes down in a big gulp. Evidence indicates that on sunny days, these wading birds may even position themselves to cast a shadow on the water creating a shady area that lures small fish right to them.
Snapping turtles scavenge for meals for much of the year, but in late spring and early summer, they lurk in the shallows with only their heads exposed. If a small water disturbance such as the kicking of tiny webbed feet draws their attention, they swim under the unsuspecting goslings or ducklings and wait for the perfect moment to rapidly raise their heads and pull their dinner under the surface.
Northern water snakes are a semi-aquatic species that thrives along the shores and wetlands of Oakland County. Whether by design or accident is only known to the snake, but they will often sun on a partially submerged log in absolute stillness. Before their sunbathing session is over, a frog or small turtle may crawl up onto their log and make another easy meal for this well-camouflaged ambush predator.
The early days of summer are a perfect time to witness ambush predators in action on the wilder side of Oakland County Parks, in the wetlands of protected lands of the Six Rivers Regional Land Conservancy, the Southeast Michigan Land Conservancy and in the Huron-Clinton Metroparks.
Text and photos by Jonathan Schechter, nature education writer for Oakland County Parks. Schechterj@oakgov.com
Visit Oakland County Parks for details on all 13 Oakland County Parks.