On The 21st: Scientists have found eggs in male fish in the Des Plaines river, and researchers suspect the culprit is pharmaceuticals and other chemicals in the water. What does that mean for fish, and for us? Plus, we learn about the migration of monarch butterflies from Mexico to Canda, and get a preview of what we can expect from lawmakers in Springfield this week.

Ready or not October is here, and it's a month full of dramatic change in the natural world. This week's commentary takes stock of what's coming (and what's going).

At last year’s plant sale by the conservation group Grand Prairie Friends, nearly 1,400 milkweed seedlings were sold. Why all the milkweed?  It’s the only genus of plants on which the caterpillars of monarch butterflies feed and develop. Knowing that monarch populations are in trouble, people here and across the country are doing what they can to create monarch havens in their own back yards.

Monarch Butterflies are declining rapidly as a species—by a staggering 90 percent in the past two decades. Butterfly milkweed, an easy-to-grow perennial characterized by attractive foliage and bright orange flowers; it is also the only plant fledgling Monarch caterpillars feed on. People can provide important habitat for them in home landscaping—just by cultivating some milkweed for the caterpillars to feed on.