Scientist, Author, Educator, Tree Canopy Biologist

Sex Sizzles In The Summer

“The earth laughs in flowers.”–Ralph Waldo Emerson

An idyllic summer evening in nature evokes a smorgasbord of sights, smells, and sounds—golden sunsets, chirping crickets, light shows by blinking fireflies, and wafts of floral perfumes. For anyone who grew up in New England, this summer imagery may conjure a halcyon nostalgia of childhood. Now in adulthood, I sometimes get a fleeting glimpse back into my youth when a sensory perception triggers those bygone summer memories. One such evocative reminder is the sound of crickets, which create surround-sound symphonies during sultry summer evenings throughout many parts of the world, not just the New England of my childhood.

Shrouded in the naïveté of youth, I never realized that a cricket symphony—like most of the sights, smells and sounds of nature—represents sex, lust and courtship. An entomologist friend, who travels the world in pursuit of six-legged critters for the Smithsonian Institution, reminded me recently that a field of chirping crickets is an enormous cacophony of mating calls. To chirp, crickets do not utilize vocal chords at all, but rub their legs together creating a long-evolved, high-pitched noise called “stridulation,” and this chirping is unique to each species of cricket. In a midsummer pasture, insects are frantically calling for a mate, not—as we humans imagine—singing softly as a soothing backdrop for families sitting on their front porch or roasting marshmallows by a fire. The short mating season of a North American cricket requires a strategy to “make hay while the sun shines”, gaining full advantage of long days and short nights, warm weather, and abundance of summer foliage. In several short weeks, crickets and their relatives must court, mate, lay eggs, hatch offspring who in turn feed voraciously on leaves, and undergo metamorphosis that triggers the cycle all over again the following year.

As kids, we estimated air temperature by counting the number of cricket chirps for one minute, and then calculating a simple formula. Who needed television or computers? We had our own personalized weather forecasters on six legs! And we never once suspected that their chirping frenzy was all about sex. Similarly, we collected fireflies in bottles, admired their bright abdomens with joy, and then released them. Few children understand that the abdominal light of fireflies is another of Mother Nature’s sex symbols, used to attract a mate during the all-too-short summer season of courtship, reproduction and child-rearing. Allegedly, the brightest and most frequent semaphores insure the best success for attracting the opposite sex.

Birds are not much different. Singing peaks in early summer, when the competition for mates is most intense. Presumably, the loudest, most lyrical or most elegant songs attract the fittest mate. In the feathered world, we humans are simply voyeurs with the good fortune of overhearing the symphonies of bird courtship in the canopy overhead. Meanwhile, underfoot, the scents and colors of summer wildflowers—clover, buttercups, daisy, Queen Anne’s lace, Indian paintbrush, to name just a few—serve as sensory sentinels similar to the red lights of a brothel. Color is a flower’s way of announcing, “I am open for business—pollen and pistils available for any eager bumblebee.” The competition is fierce. Due to a plant’s inability to move to actively seek pollinators, flowers create lures of odor or color or form to attract insects, which in turn insure a good seed set. The world of plants, as viewed from the eyes of their pollinators, is essentially one of deception, bribes, and persuasion—there is nothing innocent or Victorian about a summer wildflower bouquet.

I sometimes wish that I never trained to become a scientist—instead retaining my simple childhood notions that a field of wildflowers was a profoundly beautiful application of God’s paintbrush, that bird songs were an almost-celestial symphony emanating from tiny bundles of feathers, and that cricket chirping was a great way to calculate the air temperature. But, science teaches us an overwhelming respect for Mother Nature: her world is a precision machine operating in synchrony at all levels. Such a complex engineering design deserves a moment of appreciation and awe on a summer evening—so don’t forget to pause and applaud the crickets, inhale the floral perfumes, and admire the exquisite melodies of the day’s last birdsong.

Article by Dr. Meg Lowman (aka CanopyMeg) in the Huff Post Science Blog. Lowman is a contributor for the Huffington Post — watch for Meg Lowman on Huff Post!