Saturday, July 21, 2012

"Blog" - The Tree Frog

"Hello, is this the Tree Frog House?"

 We have lived in our house-surrounded-by-woods for 15 years now. For 15 summers Gray Tree Frogs have added to the many amenities we enjoy out here on these ten acres. We are grateful for the blessing to be embraced by the quiet.

Quiet, living this far out in the country, includes:
  • Coyotes - occasionally yipping or howling in the extreme darkness
  • Sandhill Cranes - calling all day from late February through October
  • Barred Owls - at dusk, asking "Who-cooks-for-you?"
  • Pileated Woodpeckers - big-bodied; powerful beaks hammering the hardwoods
  • Spring Warblers - their eagerly anticipated migration, and exquisite, expressive songs

Our small wetland is alive, first with Spring Peepers, joined soon by Chorus Frogs. Then, beginning in late April to mid-May, that unmistakable, resonating trill of the Gray Tree Frogs. First we hear them from a distance. One will call, with long stretches of time between calls.

By the end of May their resonant trill is heard closer in, and more frequently; by more individuals, especially on warm, humid days. But it's difficult to determine where the sound is coming from. Is it wedged in the eaves?  Ducked under the deck rails? Tucked in the table? Hidden in the shade of the potted plants around the deck?

By June and July we hear them frequently, and see them occasionally. Various authors describe its call in various ways:
  • a slow, musical trill
  • a resonant, flute-like trill
  • a loud churring sound
  • similar to the call of the Red-bellied Woodpecker
  • note: cooler temperatures means a slower trilling
  • the expanding dewlap (throat pouch) quivers as he calls
Listen to this recording from youtube :

When at rest, the Gray Tree Frog has a deflated throat that vibrates at a very low amplitude. Then, to call, his whole plump body contracts and suddenly looks skinny, while his loud, penetrating churring sound erupts at the same time that his throat balloon inflates. As you can tell by my use of the pronouns he and his, only the male tree frog produces this call. Females prefer the longer-lasting calls when choosing a mate.

This small (1.25" - 2") amphibian  (the female may be slightly larger) is seldom seen on the ground or at water's edge, except during breeding season, when eggs are laid under moist vegetation, in a temporary pond or wetland. Females lay about 2,000 eggs; hatching in four days, then need four months to achieve the juvenile size and form. The younger frogs are usually greener, before they turn gray/green, and develop a pattern of darker marks on their back.

 Except for the brief breeding season, they are mostly solitary. They mainly forage aloft in trees and shrubs. This is called arboreal, or tree dweller. The life span is about seven years.

They are experts at camouflage; especially in their native habitat, clinging to the rough bark of larger tree trunks.

(This shot is very close to life-size, on a laptop)

Well concealed here on the trunk of one of our Red Oaks; its colors and pattern blend well with the light/dark pattern of the bark and splotches of lichen.

The Gray Tree Frog is normally gray or green, but has other variations: brownish, pearl-gray, pale green, and gray-green. They are somewhat adaptable in color, but are very slow to change. The light spot beneath its eye is a distinctive field mark.

The concealed surfaces under the hind legs are a golden yellow, mottled with black.

The skin on its back is quite warty for a tree frog. The warts are numerous, but small compared to the common American Toad.

Checking the Range Maps, they are found from southern Canada and Maine, south to the Gulf states and northern Florida, but generally east of a line from Minnesota to eastern Texas, in the eastern United States.

Genus:  Hyla   Species:  versicolor   (as in versatile colors)

Predators: Raccoons, Skunks, Crows, and Snakes.

(Northern Ribbon Snake)

It seems like only yesterday when I taught "Nature Study" at Kentwood Public Schools, (Kentwood) where my students assigned me the title "Father Nature". We kept several animals in our middle school classroom, and one of the easiest to maintain was a terrarium of Gray Tree Frogs.

I would collect three or four in early September, and we kept them alive and well until early May, when I would release them into our woods, exactly where I had found them.

Students would volunteer to be responsible for the care and maintenance of the collection of animals in the classroom. Supportive parents would bring their children in early, before school began, knowing that their kids would develop responsibility along with what they would learn while doing the "work." These "PMTs" (Pet Maintenance Technicians) would feed crickets from VI Pets (VI Pets) to the Gray Tree Frogs throughout the school year. I relied on them, and they were reliable.

I have been retired for four years now. A few weeks ago, my favorite PMT invited me to her Open House - Graduation party. Kailie cried when she saw me, and gave me a big, warm hug. She still had her infectious enthusiasm and lovely smile. Kailie has grown into a charming young lady. She will be attending Aquinas College, (Aquinas) here in Grand Rapids. Kailie told me she wants to be a Teacher.

Okay, now let us leapfrog back to the classroom. Occasionally the frogs would would trill, especially, it seemed, when we studied Amphibians in the spring.

I remember once when my students coaxed me into doing my repertoire of bird calls during our nine-week Spring Birding session. I was imitating an Eastern Screech Owl, when a Gray Tree Frog replied from his terrarium. I didn't know what I was saying in the frog's language, but we held a conversation, intermittently, for several minutes. Perhaps he was petitioning for an early release, based on his good behavior.

All of the frogs were released, and continue to thrive in our woods, on our house, on our deck. I still get a little thrill when I hear the little trill of the Gray Tree Frog. And when we're reading in our library during these warm summer nights, I see a Gray Tree Frog using the sticky discs on his toes to cling to the windows.

Four toes on front feet, five toes on back feet.

We get a good look at his white belly, and a glimpse of the yellow under his legs. I think I'll name him "Blog". He is feasting on the insects drawn to the lights, as we feast our eyes on this marvelous little creature. And we welcome these summer tenants to our Tree Frog House.

I'd like to think that these must be the offspring of the tree frogs that spent the school year entertaining my students, and providing them with hands-on learning experiences during our study of Amphibians.

Now, four years later, I feel blessed to still be teaching, and reaching thousands of "students" around the world. And, although I can't see your faces, I appreciate getting feedback and comments from you, as I  Blog the Tree Frog.

(Click on photos to enlarge)

Photo LocationsHome Woods, Cannonsburg, Michigan


Peterson Field Guide - Reptiles & Amphibians (Peterson) (Eastern/Central North America)

summer world (a season of bounty) - Bernd Heinrich (Heinrich)