Walking with Nature: The Gateway Wetlands in October

Near the end of October, I walked in the Gateway Wetlands for the first time with my daughter Sherri and her small dog, Lillie. Lillie, who is a mixture of pug, chihuahua and terrier, was the first to spot the woolly bear near the side of the path. The woolly bear is neither woolly nor a bear. It is a 13-segment caterpillar with a coppery brown band between two black bands. Its coat is stiff and bristly, not furry despite its soft appearance. Fortunately, although Lillie is curious, she is gentle and was not interested in touching or harming the woolly bear, just observing and smelling it. On the other hand, next spring if Lillie sees an Isabella tiger moth (Pyrrharctia Isabella), of which the woolly bear caterpillar is the larval stage, she probably would try to catch it.

The woolly bear, which is common throughout much of the United States in the fall, is the subject of folklore. At one time it was believed that the severity of the coming winter could be predicted on the basis of how many of its segments were brown and how many were black. This was not just an old-wives tale. In the 1940s and 1950s, Dr. C. H. Curran, Curator of Insects at the American Museum of Natural History in New York City, actually tried to prove it was true. In the end, though, it turned out that the woolly bear is no more reliable a predictor of winter weather than the groundhog called Punxsutawney Phil.

Just for fun, though, there is an annual Woolly Worm Festival in Banner Elk, North Carolina, on the third weekend of October. It is a fundraiser for local schools and other good causes. Put it on your 2014 calendar and—with a small entry fee and a lot of good luck—you might race your woolly bear caterpillar to the championship and win $1,000. The winning caterpillar is selected as the weather forecaster for the upcoming winter. Each of its 13 segments, beginning at the head end, is said to represent one week of winter (see http://www.woollyworm.com/).

Woolly bears are not destructive creatures, though they nibble on asters, sunflowers, and other plants, as well as on some trees. Throughout the winter, they hide under piles of fallen leaves, in hollows of trees, or in other somewhat protected places. One amazing feature of woolly bears is that they can survive severe cold. In fact, they can be trapped in ice during the winter, and come to life when the ice defrosts in the spring. It is not yet known how they fare if they are frozen and defrosted numerous times during the winter (we know what that does to Chicago-area roads).

In the spring, parasitic flies lay their eggs inside woolly bears, and eat away at the caterpillar’s innards until the flies “explode” into the world. According to an article in National Geographic News (see http://news.nationalgeographic.com/news/2009/03/090313-self-medicating-caterpillars.html?source=rss), the woolly bears self-medicate, eating leaves full of alkaloid. Woolly bears that are not infected by the flies eat only a little of these alkaloids, which make them poisonous to other species. Those who are infected eat a lot, and are cured of the injuries caused by the flies. Scientists don’t think the woolly has figured out how much it needs; it is likely that those who need more alkaloids develop a craving for it. Had Lillie tried to bit the caterpillar, she surely would not have liked the snack.

Lillie was also interested in another miniature resident of the Wetlands which can be seen at this time of year, the autumn meadowhawk dragonfly (Sympetrum vicinum, previously called the yellow-legged meadowhawk, though the legs are not always yellow). When I spotted this bright red dragonfly with its transparent wings on the bridge, Sherri held Lillie back so I could get some photos.

The autumn meadowhawk is in the skimmer family and prefers wetlands, but it does not skim across the water looking for a meal. Instead, it frequents the edge of the pond and may travel further from the water seeking mosquitoes, flies or other insects to consume. I did not witness an autumn meadowhawk laying eggs, though you might have that opportunity later this week; they are said to lay eggs after an autumn rain. The process is quite interesting. You can read about it on a website of the Forest Preserve District of DuPage County, Illinois, at http://observeyourpreserve.org/species/yellow-legged-meadowhawk.

Unlike many other dragonflies, the autumn meadowhawk often lets people get close to it, even landing on a person’s clothing sometimes. However, as soon as Lillie approached, dragonfly took off.

Lillie did not see the other reddish insect that caught my eye—it was too high above the ground on a milkweed plant. I have seen adult milkweed bugs at the wetlands during the summer, so perhaps I should not have been surprised to see a nymph on a milkweed this week. The milkweed bugs are bright orange, which warns predators to leave them alone. Sap they suck from the milkweed is turned into a toxic compound in their bodies. It is not harmful to the bugs, but tastes bad and is potentially lethal to birds and other predators who might otherwise be tempted to eat a milkweed bug. If a bird tries to eat one, it is not likely to ever consider eating another!

Lillie did not mind that the goldenrod is no longer golden, or that we saw no herons fishing, no ducks or geese on the ponds, no turtles. She reminded us that there is beauty in nature in all seasons, and that if we look carefully, we can see something interesting, even if we don’t stop to sniff at everything along the path.

With or without a small dog like Lillie—and with or without the wildflowers that bloomed in the spring and summer—the Gateway Wetlands provides a beautiful and interesting place to walk.

NOTE: You can access the wetlands from several places, including a parking lot on Anna, west off of Janes, just north of the Promenade. Or go north on Feather Sound (across Boughton Road from Macy’s) and park on the street near the bridge.

©  Wilda Morris