Saturday, August 22, 2015

Treefrog In Transition

Text and photos by ©Nancy Partlow

Several nights ago, I heard the call of a male Pacific Treefrog  (AKA Pacific Chorus Frog) through the bathroom window - Cree-EEEEK.  I could tell that it was probably somewhere in the covered walkway between the carport and the back patio, but thought I didn't have a prayer of finding it.  A few days later when I was rummaging around in a wheel barrow full of gardening paraphernalia I sometimes keep parked in this area, a little tan and brown spotted frog suddenly appeared on the rim of the barrow.
I figured it might have been hanging out in an open bucket of fresh planting soil, seeking a cool refuge from the recent heat and drought.  Greeting the little creature, I ran a bit of water into the bottom of a plastic watering can, which I then set beneath the wheel barrow. I did this because I’ve occasionally found tree frogs hiding inside watering cans on my back patio. 

Two mornings later, I searched for the frog but didn’t immediately find it. On a hunch, I checked the area around the hose connection a few feet away. In my experience, chorus frogs periodically loiter there, perhaps for the moisture.  Sure enough, I spied it on the hose rack next to the faucet, tightly snuggled between the coils of a black rubber hose.

By this time, the frog was not brown but a combination of green and brown. 

BB & B readers may recall a previous blog about chorus frogs where we wrote about this species’ ability to change color through the use of pigment cells in its skin.  In researching the literature about this neat trick, I discovered some disagreement among scientists as to why these frogs change color.  In my admittedly-unscientific opinion, they do it for camouflage.  Every time I’ve seen a chorus frog, it’s been the same color as its background. Although this one wasn’t the same hue as the hose it was perched on, (some have the ability to turn light gray), it did match the color of the plant foliage on the ground just below it.  Perhaps it had spent the previous day hiding out in that greenery, or was about to.  

Whatever the reason, the frog was beautiful. I’ve seen chorus frogs with all- green skin on their upper body, or mottled green and brown coloration, but nothing like this. Its back was mostly lime green, with tan still clearly visible along the edges.  The liver-colored spots and stripes from the previous few days were almost completely gone, although the black eye stripe was still there.
Patches of green were visible on its legs, while the cute ovals on its face reminded me of clown make-up.  I thought, "The frog is coloring a paint-by-number picture, using its body as the canvas.  How cool is that?"

I took a few photos of the little fellow, then left him to his own devices. I try not to intrude too much on the animals I see.  Their lives are hard enough as it is.

I didn’t see or hear the frog again after that day. More than likely, it was migrating from a nearby wetland to the forested area behind my house, where it would spend the terrestrial phase of its annual life cycle hiding in the shrubs and forbs, or buried in the leaf litter beneath the trees. 
I’ve been hoping to observe a frog change its color for a long time, and am thrilled to have finally caught one “in the act” in my own back yard. 
What a finished "paint job" looks like.
Courtesy USGS Amphibian Research & Monitoring Initiative
About Pacific Treefrogs:

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