Natural Events

By Jack MacRae

Here’s what’s debuting on nature’s stage in Chicago Wilderness

Early Summer

Turtle Geographic

False map turtles — like all map turtles — get their name from the thin, yellow, squiggly lines that mark their olive-brown carapace like a topographic map of the Indiana Dunes. Living in the secluded backwaters of our rivers, they enjoy life in the slow lane, spending their early summer mornings and afternoons foraging for food and devoting midday to soaking up the sun. Map turtles spook easily and dive off their basking platform at the slightest disturbance. Male map turtles have a decidedly different diet than females. The girls have larger, more muscular jaws and can crush big mussel shells that the boys can’t. The boys eat aquatic beetles and other invertebrates.

Night Moves

Black-crowned night-herons may not be as conspicuous as their larger, daytime cousins (the great blue herons, for example), but they live in more locations across the planet. They’re the most widespread members of the heron family, with populations on five continents. The carnivorous night-herons occupy an interesting niche, exploiting the same feeding grounds as other herons, only during the night shift. Scientists are easily able to study their diets; these birds disgorge their stomach contents at the slightest alarm.

Middle Summer

Red Head Childhood

The resplendent red-headed woodpecker couple dresses alike — elegantly — from beak to tail. Their dwelling is decidedly shabby chic; they raise their young in dead trees. The hatchling woodpeckers enter the world naked and blind and don’t open their eyes for almost two weeks. They’ll stay in their tree-hole home with both parents diligently bringing insects and arachnids to the hungry brood. But childhood ends abruptly. After three weeks of parental support, both adults stop feeding the begging babies and will actually force away their offspring — by now strong flyers — if they try and come back home. Tough pecking love.

Blazing Star

The flamboyantly named spike gayfeather is one of our land’s tall, purple, and totally fabulous blazing stars. They bloom from the tip down and flop if they don’t get a full day of midsummer sunshine. Known by a variety of more bland names, including marsh blazing star, this magnificent flower has dense tufted blossoms that are popular with a certain group of long-tongued bees.

Late Summer

Breeding Weasels

Baby weasels grow fast. The young that were born in the spring are full-grown and living independently by the end of July. As empty nesters, mom and pop weasel waste no time getting…ahem…reacquainted with each other. Weasel breeding occurs shortly after the young have dispersed. Long-tailed weasels have a long and unusual pregnancy, or gestation (up to 8 months). Fans of mammal embryology know that following fertilization the egg typically divides several times as it moves through the oviduct, ultimately reaching the uterus and implanting on the uterine wall. Oddly, in long-tailed weasels, the process of cell division is halted partway through. Through the fall and winter, the multi-celled blastocyst will lay dormant and unattached in the uterus. In spring, implantation will occur, normal cell division will resume, and another litter of screeching weasels will appear by Mother’s Day.

Follow the Sun

The Jerusalem artichoke, a lovely sunflower of our moist and mesic grasslands, has an acutely misleading name. It has nothing to do with Jerusalem and is neither related to nor resembles an artichoke. Sixteenth-century European explorers — who noticed the native people had cultivated the native plant — called it girasola, the Italian word for sunflower. Over centuries of mispronunciation the name has become Jerusalem. The plants produce tubers, which are often eaten as an interesting side dish. Jerusalem artichokes contain inulin, a carbohydrate that breaks down to fructose, making them a nice potato substitute for diabetics. So much has been written about Jerusalem artichoke’s notorious ability to produce flatulence that to mention it would be mere sensationalism, and I am certainly above that. Jerusalem artichokes bloom in late summer.