I was tossing, turning and swearing retribution but I was not sleeping. It was after midnight and I had someone to blame. More accurately, something to blame. The annoying sound carried across the narrow residential street, across 50 feet of lawn and up two stories.
It was the sound of a Pacific tree frog near a children’s plastic wading pool — in Seattle. One lonely male frog was advertising for a female. I had thoughts of frog legs before I finally fell asleep.
Now I hear a full chorus of country Pacific tree frogs from a mile away, led by a chorus master in their collective attempt to draw females to a large pond where egg-laying and fertilization will occur. It’s the perfect sound for a spring evening, assuming you don’t live too close to the action.
The male amplifies his voice with a resonating throat sac. The calls start about a half-hour after sunset. Calls are generally slower in colder temperatures, faster when it is warm.
The best callers earn the most female attention and the right to fertilize the eggs.
Tree frogs are mostly active at night, especially during dry periods, but are often seen during the day. I’ve found them on an outside wall, under the flap of the hot tub cover, on a car door and on a railing 12 feet off the ground.
Despite their name, tree frogs are mostly ground dwellers, using vegetation for shade or safety, or sitting there to wait for a meal to wander by. They also are found under downed logs or taking advantage of some mammals’ burrows. Tree frogs that were underground in the Mount St. Helens blast zone were one of the few vertebrates to survive, according to one study.
The Pacific tree frog is the state’s official frog and can be found from rainforest close to the sea and far up a mountain range. An adult is about 2 inches long, sporting body colors from lime green to a goldish brown, a black mask from snout tip to shoulder, and clearly divided toes with suction discs on the tip.
They are the most common, smallest and most varied in color of the state’s frogs. Despite the oft-repeated opinion that the tree frog can change colors for camouflage purposes, say in moving from grass to dirt, science offers a more nuanced explanation.
Depending on the difference between color shifts, the change can take a few hours, days or weeks.
Skin color is produced by pigment cells. Some research shows that a slow color change might help tree frogs change over the course of a season, perhaps from green grass in the spring to dead brown grass in late summer.
In addition to colors, patterns can shift, and spots can disappear and return, changes that tree frogs have some control over, according to research. Color changes also are useful because a green body absorbs more solar radiation; a brown body absorbs less.
As cool as they look, don’t pick them up. You are not in danger but their permeable skin can absorb harmful chemicals in your skin, such as lotion or bug repellent.
Columnist Sharon Wootton can be reached at 360-468-3964 or www.songandword.com.
Talk to us
> Give us your news tips.
> Send us a letter to the editor.
> More Herald contact information.
