One of the roles of the Forest Preserve of District of Will County is to provide and restore healthy habitats for a diverse and abundant number of species, and there is so much to discover and learn about in the preserves! Let’s take a look at an inconspicuous little amphibian, the gray tree frog.
The gray tree frog’s scientific name is Hyla versicolor. Hyla means timber, as in wood or tree, and that is its favorite habitat. Versicolor means “to turn colors,” and this little frog is able to do just that. In a matter of seconds, it can change color to match its new surroundings, making it difficult for a predator to spot. They may also change color to help regulate their temperature. When they are a darker color, they absorb more sunlight, which helps them warm up, while being a lighter color reflects the sun and helps them cool off.
While their color can change, they do have some patterns and marking that are noticeable no matter their color. Their skin is warty and has a blotchy pattern that mimics lichen on a tree. They have a light spot under their eyes and dark stripes running from behind their eyes to their front legs. The underside of their thighs reveals a bright yellow or orange color that scientists believe sends a warning.
Words to know
Abundant: Available in large quantities.
Bulbous: Fat, round or bulging.
Chromosome: A threadlike structure containing genetic material.
Inconspicuous: Not clearly visible.
Regulate: To control or maintain the rate or speed of something.
When fully grown, males can grow up to 1.5 inches long. Females are even larger and can grow up to 2.5 inches long. They have white bellies and throats, but when the male sings, his throat is black.
The gray tree frog has an identical twin, the Cope’s gray tree frog (Hyla chrysoscelis). They look exactly alike except the gray tree frog’s skin may be slightly bumpier. Scientists can tell them apart because each species has a different number of chromosomes. We can tell them apart because they sound different. The gray tree frog’s call is often described as more musical. Listen for yourself.
A song is born
Males start singing in early to mid-spring. They may be aggressive toward each other at this time, getting in wrestling matches that can last 30 seconds to 90 seconds. Their loud and proud calls attract females. Once a couple finds each other, the male hops on the larger female’s back and she moves them to a better location for egg laying. The female will lay between 1,000 and 2,000 eggs that attach in little clusters to vegetation in the water. They are fertilized by the male as she releases them.
From tadpoles to treetops
At every stage of frogs’ lives, they are super sensitive to their environment. Their time as an egg and tadpole is dependent on the temperature of the water. Warmer water will result in quicker development. Time as an egg can last from three to seven days.
Growth as a tadpole can range from 45 days to 65 days. The tadpoles can vary in color, but they have bright orange and black flecks at the tips of their tails. Their conspicuous tails attract predators and give these little tadpoles a fighting chance to slip away.
A frog first emerging is called a frogling. They are bright green on their backs and tops of legs, blending in well with the grasses as they make their way from their watery childhood home to the trees. Gray tree frogs can live up to seven to nine years.
A day in the life
Gray tree frogs like to eat spiders, all sorts of insects, snails, slugs and sometimes even smaller frogs. At night, they move along the trees and shrubs, making daring jumps from branch to branch as they search for food. The bulbous tips of their toes secrete a sticky substance that helps them cling as they climb. Young frogs will stay closer to the forest floor, while older frogs will make their home higher in the canopy.
If your home is close to their habitat, these clever little frogs may come and sit in your windowsill. They know the light will attract many delicious insects right to them. During the day, they hide out in tree holes, behind bark, in rotting logs or under leaves. Next time you’re on the trail, see if you can spot one of these camouflaged creatures hiding in the trees around you.
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