“How earnestly and rapidly each creature, each flower is fulfilling its part while its day lasts! Nature never lost a day, nor a moment. As the planet in its orbit and around its axis, so do the seasons, so does time, revolve, with a rapidity inconceivable.” From the Journal of Henry David Thoreau, Sept. 13, 1852

The older I get I have come to recognize that months appear to blend together, with predictable changes that herald each season in our natural world. With age comes the calming realization that our earth’s circle around a life-giving sun continues, and with experience I distinguish the time of year by what plants and animals are signaling to me.

Two months stand out to me as transformative, sharing distinct clues that the season is on the cusp of change. March and September, both months of the Equinox, were celebrated by ancient civilizations. They are the months when the sun crosses the celestial equator, and day and night share equal time and date. The Autumnal Equinox is not until Saturday, Sept. 23 but already there are clues of its arrival. Here’s what I’ll be looking for this month.

As the days grow shorter and the nights grow longer, the bird songs of spring and summer are replaced by the sounds of insects. The silent sparks of fireflies on a summer evening have been replaced by the sounds of chirping crickets and katydids, singing their ancient tunes to attract mates. Katydids began their evening calls in August, and this month the eerie “nocturne” of crickets is the song of September. It is the male cricket that chirps by rubbing its two front wings together.

The dawn chorus of territorial nesting birds no longer disturbs our morning slumbers. Thankfully, the wood and hermit thrush, deep within their forest home, will continue to practice their ethereal fluted tunes before migrating to warmer regions in late autumn. Though birds are quieter this month, they can be found gathering in flocks and gleaning food from wildflowers long since bloomed and gone to seed. Along with nutritious seeds they can be found gorging on the soft mast of our wild berries.

In our yard, blue bird fledglings and their parents have been taking advantage of our birdbath and various caterpillars and insects in our trees and gardens. Later this month I’ll be on the lookout for flickers arriving from nesting grounds to the north. Last year a large flock of about 40 female flickers visited our yard, grubbing for worms and other insects in our grass. Other insect eaters, such as our region’s diminutive warblers and wrens, will soon be heading to southern states, Mexico and South America.

Gold finches have been gleaning seeds from our front yard patch of black-eyed Susans and though a bit later to bloom this year, our sunflowers are ready for chickadees and other year-round seed eaters. Our back pasture has a healthy large patch of goldenrod, a favorite nectar and food source for monarch butterflies before they begin their fall migration. Our field and fence edges also have several large pokeweed plants; their black-purple fruit hangs in large clumps tempting bluebirds, red-bellied woodpeckers, cardinals and other fruit eaters.

The first signs of fall foliage will appear this month, with red maples the first to show their brilliant scarlet leaves, especially those rooted near wetlands. Our days are growing shorter and green chlorophyll pigment in leaves ceases to flow, allowing their true colors to appear in the dazzling blaze of yellow, red and orange colors of autumn.

Snapping turtle hatchlings are leaving their nests and heading to water. The temperature in a nest during the 9-to-12-week incubation determines the sex. Eighty-four degrees Fahrenheit or warmer will produce females, while 80 degrees Fahrenheit or cooler will produce males. This year we had a cool spring and wet July. Perhaps we’ll see more male hatchlings as they make their dangerous journey from the safety of a nest to a watery home.

Hurricane season is here, and Sept. 21 is the 85th anniversary of the great hurricane of 1938 when 600 people died, and 275 million trees were uprooted or snapped in the Connecticut River Valley. The signs of the devastation can still be seen in our woods and forests. Tom Wessells, in his book, “Forest Forensics: A Field Guide to The Forested Landscape,” describes the visible evidence of that horrific September day. “When live trees are toppled by wind or by snow- or ice-loading, their roots rip out of the ground, excavating a pit or cradle. As the tipped-up roots decay, they drop the earth excavated, creating a mound or pillow adjacent to the cradle.” All these years later the evidence of the great hurricane of ’38 can be found in the “cradles and pillows” still visible in our forests to the discerning eye.

This month the amazing return journey of eels begins, as transparent “glass eels” born in the Sargasso Sea off the coast of Bermuda are making their way from the ocean to the coast. They will swim up streams and into estuaries where they will gain pigment to their skin and become known as “elvers.” Some will migrate upstream to rivers, lakes and ponds where they will remain for about five years before returning to the Sargasso Sea to breed and die. The story of this amazing journey can be found in the 1941 book “Under the Sea-Wind,” by Rachael Carson. In the chapter “Journey to the Sea,” Carson describes in beautiful detail and lyricism the unique journey of eels from freshwater to their natal grounds in the Sargasso Sea. This is the month to look for their return.

As a child, it was in early September when that melancholy awareness set in – summer is over and it’s back to school. Nowadays, I recall that wistful feeling at the first sight of those bright yellow school buses, carefully navigating our town roads, carrying the precious cargo of our hopes and dreams.

Today is Sept. 3, and I’ll be attending the Woodstock Fair in Woodstock, CT. Always held on the first weekend of September (Labor Day holiday weekend), the fair too has become a signature event that marks September as a month on the cusp of change. Perhaps I’ll see you there. We live in a beautiful place called The Last Green Valley National Heritage Corridor. I hope you’ll join me, every day of every month to care for it, enjoy it, and pass it on.

Information for this column was gleaned from “Naturally Curious: Day by Day,” by Mary Holland, “New England Nature Watch: Month-by-Month Guide,” by Tom Long, “The Journal of Henry David Thoreau, Volume IV May 1852 / February 1853,” edited by Bradford Torry and Francis H. Allen, and “Forest Forensics: A Field Guide to the Forested Landscape,” by Tom Wessells.

Bill Reid is the Chief Ranger of The Last Green Valley National Heritage Corridor. He can be reached at 860-774-3300 or by email at bill@tlgv.org