Today, Thursday, the 23rd of September 
2010, is the autumnal equinox in the northern hemisphere, otherwise known as the first day of fall.* Our night and day will be as close to equal length as will happen all year. And while the sun has crossed the celestial equator on its way south many of the birds we love to watch are also halfway home on a long journey.
Here in the northeastern United States apple crops are being picked, some of the early-turning trees are becoming a brilliant yellow or a rich red, and we are getting our first Dark-eyed Juncos of the year, always a harbinger of cooler weather to come. My first junco of the fall was earlier in the week at the Jamaica Bay Wildlife Refuge and I watched and digiscoped it kicking and scratching in the middle of a trail looking for seeds for about ten minutes. I might not pay so much attention to another Junco hyemalis until next autumn.
Why the close attention to the junco? Well, an interesting and little-known fact** is that one can prognosticate the severity of the upcoming winter by the color of a junco’s feathers. Apparently, the lighter in color that the back feathers are the more likely that the coming winter will be harsh with lots of snow, as the lighter color helps with camouflage. As you can see from the feather detail image above, which you can click for a larger version, we are in for a doozy of a winter!
What about you? How do you know fall is here? Birds? Leaves? Produce? Or something else entirely?
*Though some calenders say that yesterday was actually the first day of fall. Not being an astronomer, I can in no way make an educated decision as to who is correct.
**And quite possibly one that I just made up on the spot.
…
Me?
I know fall is here because the deadline for my many reports at work this year is getting closer every day.
Sigh.
The fall in Ecuador is marked by the planting season. Most of the Andes get planted in the fall and harvested in the summer.
Our ancestors were keen monitors of the changing seasons so their food supply would be plentiful. For this purpose they studied astronomy and determined that the equatorial line, the only place on earth where there is no shadow at noon on the solistice, passes near Mitad del Mundo the town near Quito where the equatorial monument lies.
The fascinating fact is that our ancestors, more than a thousand years ago, determined this line with great accuracy while the French Geodesical expedition mistakenly determined this line with an error of 300 meters. So when you come to Ecuador (to see the birds) and visit Mitad del Mundo, remember that the statue actually lies on the French line and not on the true line.
I know fall is here when the early mornings become so dark that I have to don my stupid reflective bib in order to get a run in before work. Halloween candy in the stores doesn’t work as a marker, sadly … I saw that in August. 😛
My unsubstantiated Junco factoid in my own little head is that the later they arrive in my Chicago-area yard, the milder the winter. So far as of October 17, I have only had migrants-none of my winter regulars are here yet. Here’s to a mild Chicago winter, which still can be pretty nasty. Nice site. Thanks.