The cool nights of mid September herald the change of the seasons. The once raucous night calls of katydids and tree crickets of summer literally slow down as the autumn unwinds. Soon the nights will be silent of their song and winter’s grip will be upon the natural world.
There are many such seasonal observations that one can notice. While life winds down towards dormancy in the temperate regions of the world, there are still many last blazes of glory to observe… flowers blooming, birds migrating, leaves changing color, all designed to take advantage of seasonal weather patterns and unique opportunities.
While a majority of plants bloom in spring and summer, a notable few wait until the last possible moment to send flower. A hiker at Robinson Park has an opportunity to see an orchid blooming on a sunny hill prairie. October Lady’s Tresses put forth rows of white flowers on a spike that stands a few inches high. Only growing in a few counties in Illinois, it is an uncommon find for the hiker. Its fragrant flowers entice the remaining, ground-nesting bees for a final treat of nectar and pollen.
The autumn prairie also has other attractions to insects. Downy Gentian bursts with intense blue flowers, while its close relative Creamy Gentian sends white flowers to grace our prairies. Its flowers are stubborn, barely opening. It takes a good sized bumble bee to pry open this bloom to get to the prize inside. All of this prying and prodding makes sure the bee gets a good dose of pollen and insures the survival of the next generation of gentians. It is a method of pollination the two have worked out in a long dance of survival that goes back millennia.
Asters and goldenrods of various species bloom in autumn. Their nectar is crucial for late season butterflies. Some will overwinter as adults, but the Monarch Butterfly will fuel up on the nectar of asters and goldenrods for an amazing migration that will take them to the mountains of Mexico. On the delicate wings of butterflies our prairies are connected to distant lands.
Migration is a strategy that allows species to cheat winter’s icy grip, but the effort is full of perils. Shorebirds and hummingbirds take the trek south in August. Wood Warblers of many species journey in September. Migrating birds take advantage of seasonal weather patterns to aid their flight. As autumn’s weather patterns push cooler air from north to south, birds will “surf” these weather fronts to get a good tailwind.
October’s skies are the realm of the waterfowl. Ducks and geese are fueled for their journey by the seed production of late summer, combined with the higher water levels from autumn’s rains. Throughout summer’s dry season, water levels in backwater lakes of major rivers like the Illinois drop. This exposes vast mudflats that grow up in a myriad of moist soil plants. These ephemeral plants grow quickly and go to seed just in time for the increased rainfall of autumn to flood their temporary terrain. The combination of plant seeds and flooded backwaters are a boon to waterfowl that time their trek with this annual cycle of river’s flood pulse.
We often think of autumn as a winding down towards a stillness of winter. In reality it is a season of immense activity. It is a well choreographed spectacle that rivals spring’s unfolding. The timings of nature are like a well tuned clock. Each tick-tock of this celestial clock is intertwined with gears and cogs that are often overlooked, but the interplay and existence of each one is imperative for the success of the other. It is an interdependent world in which we live. Autumn highlights this interplay of species like no other season. Will we take advantage of the few remaining glorious fall days to enjoy this season? After all, we are parts in this celestial clock as well.
Author’s note: This column is named “Nature Rambles” in honor of Virginius H. Chase, a self-taught naturalist born in 1887 in the booming berg of Wady Petra in Stark County. Chase was a great grandson of Bishop Philander Chase of Jubilee College fame. Virginius Chase wrote a weekly column, Nature Rambles, in the Peoria Star from 1933 to 1936. He was a founding member of The Peoria Academy of Science and lived to the ripe old age of 90. His botanical specimens can be found in herbariums throughout the United States.