By Rod Myers, Naturalist
It wont be long before spring is here. The sky is getting brighter, and even as early as February, the day lengthens an average of three minutes a day. We have seasons because the tilt of the Earth in relation to the sun changes in a yearly cycle. Our Northern Hemisphere tilts toward the sun in the summer, reaching its closest tilt during summer solstice, which occurs June 21 this year at 3:10 p.m. This is the official beginning of summer.
Our farthest tilt away from the sun this year is Dec. 22 at 2:04 a.m., which is the official beginning of winter.
The sun didnt always have the slowly-moving tilt cycle, according to scientists. Its believed that about 4 billion years ago, a large asteroid hit the Earth, knocking it off kilter. Its presumed this asteroid was so big, the impact sent billions of tons of Earth into near space, much of which was molten due to the heat of impact. Most of this material never left the pull of Earths gravity, though it was large enough to exert its own force, and thus has slowly pulled away from Earth. This material massed on itself, and, after enough revolutions around the Earth, became round. This object is still moving away from the Earth at a rate of 5 inches per century, and the object Im talking about is the moon.
These theories existed before men landed on the moon but were confirmed when astronauts brought back moon rocks that had the same chemical signatures as Earth. That is Earths fingerprint, so to speak, and no other celestial body has the same print unless it came from here.
Moonlight is a tremendous aid for night-seeing creatures. It aids them in finding one or more mates and may also stimulate mating behavior. People find the moon romantic, or possibly we believe that because weve been told its romantic by past generations who stayed up all night watching half of creation creating.
Some in the pre-mating mode, such as male frogs, use a species-distinct call to attract a mate, and yet throw their call so its hard to pinpoint the source. The call is thrown in a ventriloquist-like fashion to avoid predators. Then how does the female pinpoint the call of her future hunk of heart-throb? Probably by three methods and possibly more. One would be the frog ear, which has changed little in 240 million years. The second would be chemical receptors in the skin, but male and female would have to be connected by the same network of water. Of the four, this connection would take the longest to achieve. The third method would be vibration, wave action. Again, theyd probably have to be connected by the same body of water, but mud or vegetation may act as a sub-par medium.
A fourth method may be moonlight or other light sources, even the sun if the frogs call in daylight. But the moon seems to be more ideal. Picture a love-thirsty male frog calling in a small pond. Hes part way out of the water, so when he expands his throat with air to make his species-specific mating call, the throat bubble is partly submerged, sending out vibratious noise shockwaves through the water. The shockwaves would be rings that expand outward in an ever-growing perfect circle around the frog. You could achieve a similar effect by dropping water droplets into a cup of water. For humans, frog call shockwaves are hard to see or feel, but for a frog, they appear like motorboat waves or at least how motorboat waves appear to us.
So, OK, ladies, pretend youre a female frog in a pond and pretend Im Barry Frog White describing this communication process. OK, baby, first off, you hear your potential male frog lover with those sexy little frog ears of yours. Oh, yeah, youre gettin in the groove, baby. Now youre feeling the water waves from his throat vibrations, and theyre lapping against your trembling, cold, wet body, oh, yeah. By now, your chemical receptors are telling you this male frog is a biochemical hunk. Youre drinking it in, baby, youre in the love groove. Then, suddenly, a full moon comes out from behind a cloud bank, and, instantly, those bursts of ever-growing vibration water shockwaves coming from your male are marked by a shimmer of moonlight. Yes, baby, every little wave has a spot of light that radiates toward you. So follow the beacon on the runway of love, baby. Get the picture? Of course, a predator might hone in and eat the frog, but love is always a little dangerous.
Maybe thats why frogs call more on warm, cloudy nights, but that could have something to do with humidity. Ninety-nine percent of what man knows about the universe beyond Earth, he learned from studying light. Perhaps nocturnal representatives of the animal kingdom know their share about the cosmos by observing light. Maybe they know more about the moon than we do.
Rod Myers is a local resident with an interest in the environment and disability issues. He has an associates degree in science and a bachelors in fine arts. Rod is a member of the Audubon Society, the Wild Ones Natural Landscapers and Rockford Amateur Astronomers, Inc.