Gray Tree Frog


tree frogThe chameleon of the frog world. That's how some people describe the gray tree frog – a name that implies this animal is always the same color, and ignores its ability to adapt to backgrounds ranging from gray to green.

With a white spot under both eyes, a white belly and yellowish-orange markings on the inside of its hind legs, the gray tree frog is a handsome and exotic-looking amphibian. Closer examination reveals large adhesive pads on the end of its toes, which allow it to cling to vertical surfaces. But, certainly, this amphibian's most curious feature is its ability to change colors much like the more-famous lizard with the same trait, the chameleon.

Though common throughout much of the southern United States, the gray tree frog (Hyla versicolor) has been found as far north as the Canadian provinces of New Brunswick and Manitoba. In Oklahoma, they live wherever they find small ponds, roadside ditches and other pools of standing water. The best habitat is shallow water located close to mixed stands of willows, oaks and pines. The frogs also prefer lots of overhead vegetation, and fallen branches or extensive vegetation along the water’s edge. They often congregate in areas with an abundance of shrubs and vines.
During the day, gray tree frogs hide on or beneath rough tree bark, in hollow trees and on leaves. They tolerate high temperatures quite well, and they're most active during the summer, when humidity is high.

Their remarkable ability to climb or rest on vertical surfaces is the result of a mucous layer produced by toe pad cells. This mucous creates a sticky bond with the vertical surface that’s strong enough to support the frog’s weight.

In regard to diet, the gray tree frog is an opportunistic feeder that eats mostly insects, spiders and other invertebrates.

This frog’s breeding season lasts from early April through July. Males begin calling at breeding sites when night air temperatures reach around 60 degrees. Their calls resemble musical, birdlike or buzzing trills, and the chorus attracts females to the site. The frogs then breed in water.

Afterwards, each female may produce between 700 and 3,800 eggs, and biologists have documented individual frogs producing multiple clutches in a single season. Eggs are light brown, and they measure barely 1/25-inch in diameter.

After they are deposited, the eggs attach to floating vegetation in clumps of 30 to 40 eggs. They hatch in only four or five days, and the tadpoles completely metamorphose within two months. Young frogs typically stay near the breeding site for the remainder of summer.

Fortunately, most land use practices are not detrimental to the gray tree frog’s survival, as long as some shallow ditches or ponds are left undisturbed. The gray tree frog is an interesting component of Oklahoma’s natural world, and discovering one can be the highlight of an outing. So, while you’re out this summer, keep a sharp eye out for the chameleon of the frog world – the gray tree frog – which may be gray or green or anything in-between.