The creek reads clean on the standard water-quality assessments—all designated uses supported, the official forms all signed off. But walk the riffles at dawn and watch the herons and mergansers that have made this stretch home, and you're watching a different story. The treatment plant upstream has run mercury nearly 275 times its permitted limit in a single quarter, with exceedances in every quarter over the past year. Manganese has spiked as high as 460 percent over the standard. These metals don't disappear in the current; they settle in the sediment and climb the food chain—from invertebrates into small fish, and from there into the bodies of the wading birds that have become the true sentries of what's happening here.The regulatory data lag behind the ecological one. Water-quality profiles may show compliance next quarter, but the birds accumulate what the instantaneous tests don't capture: a year of exposure, chronic ingestion, the slow weight of bioaccumulation. They are living records of an excess the system has already forgotten how to measure against.
Monarchs laying eggs on summer milkweed
June 24, 2026
The milkweed along the roadsides and field edges near Wexford is fully leafed out now, the broad leaves a deep, waxy green in the early summer light. This is what a female monarch has been looking for since she arrived from the south. She doesn't stop at every plant. She lands, drums the leaf surface briefly with her forelegs, and moves on, or she stays. That tapping is how she tastes the plant, detecting the chemical signature of milkweed before she commits to laying.Monarchs are the only butterfly in this region that can complete their life cycle on milkweed, and common milkweed is the plant most available to them here. The relationship is specific and tight. Milkweed produces cardenolides, a class of toxic compounds that make the leaves unpalatable to most insects and dangerous to vertebrates. Monarchs have a tolerance for these compounds that other butterflies lack. A female will lay a single egg on the underside of a leaf, usually a young leaf near the top of the plant where the cardenolide concentration is slightly lower. She may lay hundreds of eggs over the course of a few weeks, rarely more than one per plant, spreading the clutch across as many milkweed stems as she can find.The egg hatches in three to five days. The caterpillar's first meal is often the eggshell itself, then the leaf. As it feeds and grows through five instars, it accumulates the cardenolides in its own tissue. By the time it pupates, the toxins are concentrated enough that a bird that eats it will become nauseated. Most birds learn quickly. The bright yellow, black, and white banding of the caterpillar is not camouflage; it is a signal that this animal costs something to eat. The adult butterfly carries those same compounds, which is why the orange and black wings are worth recognizing. The great spangled fritillary, also flying now near Wexford, shares some of that orange coloration, though it is a different animal entirely with different habits and a different larval host. The visual overlap is real but loose.What the milkweed gets from the monarch is less obvious, but the plant does produce nectar in the flower clusters that are beginning to open now, and monarchs, like other butterflies, visit those flowers. Milkweed pollen is packaged in sticky masses called pollinia that attach to the legs of visiting insects and are carried to the next flower. Monarchs are among the insects that move this pollen, though they are not the primary pollinators. The plant's reproductive success doesn't depend on them the way the monarch's does on the plant.The pressure on this relationship comes partly from habitat. Common milkweed grows in disturbed ground, field margins, roadsides, and patches of open land between woodlots. Near Wexford, that open ground is also where invasive plants like purple crownvetch and Morrow's honeysuckle establish themselves, both of which are present in this area now. Crownvetch, an invasive ground cover, spreads in dense mats across the same roadsides and disturbed edges where milkweed would otherwise grow, reducing the area available to it. Milkweed is resilient and spreads by both seed and underground rhizome, but it competes for the same light and soil. Fewer milkweed plants in the landscape means fewer places for a female monarch to lay, fewer caterpillars to complete their cycle, fewer adults to make the fall migration south.
