DOOR COUNTY ADVOCATE (Sturgeon Bay, Wisconsin) 15 September 07 Decline of frogs should be a warning to us (Roy Lukes)
There is an amphibian found in 26 states and in most of Canada, widespread throughout Wisconsin, that is the state amphibian of Minnesota and considered an endangered species in Alberta, Canada today.
It became the star performer on our hike with friends recently at the Point.
Actually our goal was to find, enjoy and study mushrooms, but the recent dry weather put an end to that intention.
Three beautiful and welcome leopard frogs made their individual appearances, always when least expected, in the big field at least a quarter-mile from the nearest water.
One of their nicknames for years has been the meadow frog because their appetites and great hunting skills frequently lure them well away from the wet environments to where most people would least expect to find them.
These amphibians are extremely beneficial to farmers in that they consume many agriculturally destructive insects.
Ironically, it has been determined that some of the people who can benefitt from these animals are also, through excessive use of pesticides, causing them great harm.
All three of the moist and glistening, smooth-skinned specimens we lucked onto appeared to be adults at least three or more years old and upwards of 3? inches in length.
What pleased us, especially those of us intent in photographing those unusually accommodating and patient anurans, was how still they remained, beautifully camouflaged with their natural surroundings. As long as we moved slowly, they remained perfectly motionless.
All three had either predominantly brown or green color with irregularly spaced and shaped dark chocolate brown spots, most of which were thinly outlined in light yellow.
The ventral (underside) surfaces of those frogs were white and their gorgeous eyes shone like little jewels.
Later, in carefully analyzing their close-up portraits on our computer screen, I tried to determine where on the top of their heads between their eyes the so-called pineal eye was located.
This is a light sensory structure on the dorsal (upper) surface between the eyes of frogs and salamanders which biologists think may be used by these creatures to find their way back to water.
Mating occurred early this past spring, eggs were laid and immediately the adults headed for better food sources.
The result was leaving the eggs to hatch and the tadpoles, and later the young frogs, to fend for themselves.
Studies have shown that individual leopard frogs have a definite home range and will return, up to a point, when displaced or when they wander too far away.
Now it is absolutely vital that they return to water in which they must safely spend the winter.
The wintering place for a leopard frog is referred to as its hibernaculum and is usually at the bottom of a pond, stream or other body of quiet water, usually at least several feet deep.
The frog does not bury itself in the mud in winter but simply lies torpid on the bottom in the water, often beneath the ice.
I have a retired friend in central Wisconsin, an active amateur naturalist who, among other skills, has done a lot of scuba diving during his lifetime.
Lately he has been going beneath the ice of several rivers to study the frogs during their quiet wintering months.
What has upset him is finding thousands of leopard frogs dying and dead on the bottom of the shallow rivers while, above on the ice, dozens of snowmobilers continued to race up and down the frozen surface.
My friend contends that the wintering frogs, naturally in great stress while remaining under water without food for several months, are unable to contend with the constant noise and disturbance from overhead and are dying as a result.
So far the professional biologists have lent my friend a ?deaf ear.? Only time will tell.
Door County is fortunate to have at least nine species of frogs and toads: the eastern American toad, western chorus frog, northern spring peeper, Cope?s gray tree frog, eastern grey tree frog, bullfrog, green frog, northern leopard frog and the wood frog.
Extensive ecological studies over the past years have revealed that the health of a frog population is a direct reflection of the heath of the entire ecosystem.
Sadly many of our native frog and toad species have been decreasing drastically.
Adding insult to injury, federal funding for an important study regarding the high degree of deformities, especially in leopard frogs, was cut in 2001.
The decline of these amphibians is a very serious matter.
These creatures? sensitivity to and intolerance of chemical pollutants in the air and water, or an increase in the ultra-violet rays in our atmosphere, frogs above ground are to us like the caged canaries were for years to miners below ground.
There is no simple answer to this dilemma. But in the end all of us are going to have to pitch in and do our part.
Decline of frogs should be a warning to us