Fall Equinox

One can almost feel the turning of the seasons.  The scent of the air, the alteration of sound, the way the light touches the mountains, a touch of freshness in the summer wind...all these things give hints of the change.  The fall equinox is upon us, when the days are of equal length, when the sun, traversing through the seasons, crosses the equator and heralds the beginning of fall in the northern hemisphere. This year the equinox occurs on September 22, 1.44 pm PDT.  

It is one of my favorite times of year.  The nights start to cool off a bit, and the buzzing of the cicadas starts to die down.   Everything starts to senesce and slow down, migrants start passing through, and it is a time of reflection. So the equinox is a time of equality:  day and night the same.  It is about the slow winding down of growth to the sleep of winter. It is time to reflect on the year: what it brought, what was accomplished, what is still incomplete. 

Goldenbush blooming in the desert fall.
c 2008 Ginny Short

It is funny, reflecting on the change of fall.  One of the things that comes to mind is "fall colors".  I have seen the dramatic and lovely change both in pictures and in person, and there is no doubt it is fantastic. I have been told it is even more lovely in places I have never been. Ever since I can remember I have reflected on the changing seasons, and being a desert rat, have never lived in a place where the trees change on such a grand scale.  I have had friends and strangers remark to me that there are no seasons in the southwest, and note that as one reason they could not live here forever, as reason for their homesickness when the taste of frost should be on the air.  I had a plaque on my wall in my office as a graduate student:  We have four seasons here: fire, flood, wind, earthquake.  Other plaques say "fire, flood, wind and drought!".  

But we do have seasons.  Sometimes they come on soft and subtly, like now as the barest hint of change in the wind. Sometimes they come on hard and abrupt, like a cool, breezy spring jumping to the triple digits overnight. Each season has its own finery, from the goldenbush of autumn to the ghost flowers of spring, the quiet green of winter to the desert willows of summer.  Yes, seasons change even here.  One can almost feel the turning of the season from blistering summer to sultry fall.

Desert cicada

August brings the incessant buzzing of the apache cicada (Diceroprocta apache).  This is the quintessential sound of the desert summer, like a high wire buzzing through the atmosphere. It seems to resonate in the thunderhead laden air, as if the insect is the voice of  the cumulonimbus clouds skirting the horizon. The blue sky, the air thick with moisture - I can hardly breathe in this.  The heat lays on us like a wet towel,  and even the wind is hot and thick, not with the usual freshness that our desert winds bring. The cicada is the spirit of summer and the herald of fall.

Apache Cicada on mesquite trunk.

This amazing insect is not the same as the cicadas we hear about every 13 to  17 years on the east coast. That genus is "Magicicada" and are known colloquially as periodical cicadas.  While the apache cicada may live up to 3 years as a grub, feeding underground on roots and sap, they do not have the quirky and fantastic 17 year cycle, and we see them every year when they emerge in the hottest months of summer, their sound echoing on the landscape.

Cicadas are the only insects that have a true percussion mechanism for creating sound.  Unlike our cricket - another summer singer, that use modified forewings with a scraper and a file to create their song,  the cicada has a tympal that is vibrated by a large muscle.  This vibrant call carries up to 440 yards. There are 160 species of cicada in North America.  So let me join my voice to theirs in singing for joy in our desert summer, and in the anticipation of a glorious fall!!!