Wednesday, June 24, 2009

Tree Frogs

I came across this “cute” little green-colored tree frog today on my front porch.




Just “hanging out” in the shade during the hot part of a June day—he/she’ll be hoppin’ busy tonight though. Tree frogs eat insects, spiders, mites, and snails during the night—mostly on the ground. Although this individual is green in color, he/she is a Gray Treefrog (Hyla versicolor) which often is gray or brown, but can be green. They like moist, wooded areas which is what our home landscape is. At night they take to the trees. They court and mate from March to October, singing their little hearts out from the branches of trees. The males sing to attract females in order to … well, you know … to make tadpoles! They stake out territories and are said to defend them vigorously if another male enters in. I wonder, just how ferocious can a male tree frog be?

They live for only 2-3 years, overwintering under leaf litter, rotted logs, rocks, etc. They successfully survive our somewhat cold winters by producing large amounts of glycerol in their blood and body tissues, which acts as a sort of “anti-freeze”, preventing ice from forming in their body cells (from Amphibians and Reptiles of Arkansas by Trauth, et. al.). Plants that are cold-hardy in the winter do the same thing for the same reason. So how about that ... plants and animals produce antifreeze!

We have lots of tree frogs that show up in surprising places. They will sit and pose for a picture and even sit in your hand without trying to escape. We have so many because our “yard” is similar to their natural habitat (moist, shady with trees and lots of leaf litter) and partly because we don’t spray our trees and shrubs with insecticides. This means we are not killing either the frogs themselves or the prey that they subsist on. Also, our water garden provides a place for them to lay their eggs, where the tadpoles will develop. The coloration—either mottled gray or green—is probably more for blending into the background in order to avoid the attention of predators (like birds, especially) than it is for sneaking up on prey. Here’s a pic from last year where I noticed a green-colored Gray Tree Frog passing the day inside the canopy of my native Button Bush shrub.





Tree frogs have expanded, flattened toes with suction cups that secrete a sticky mucous which allows them to hang on to just about anything they want to hang on to—like windows or, in this case, storm doors .











At night, in the summer, all kinds of insects are attracted to our windows, either from the porch light or to lights inside the house that they can’t get to. So tree frogs will often congregate where the action is. They hang on to the slick surface with these sticky suction cups. You can watch them stalk an insect on the window until suddenly an incredibly long, sticky tongue darts out in a flash and the frog begins to munch his/her meal. After a few nights of this, we have to clean up tree frog poop from the window sill. It means there was lots of action for the tree frogs that week! So, even a summer front porch can be an ecological hotbed of living and dying--call it "porch light ecology". You don’t have to go to the African plains to see that—just walk outside your house and open your eyes!

1 comment:

  1. I remember as a kid sitting watching those frogs for hours on the front window. I loved it. Thanks for ingraining the appreciation for 'yard ecology' in me. Except the part that included butterfly identification at 8am on a Saturday morning...I could have done without that :)

    -nell

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