The 11-year-old tiger had received her first dose of a COVID-19 vaccine developed for animals. The zoo is now awaiting test results for other big cats that are exhibiting symptoms similar to the infected tiger’s.

Chicago scientist Heather Skeen studied the gut bacteria of the migratory Kirtland’s warbler and made a surprising discovery with potentially far-reaching implications.

One of North America’s most common native bumble bee species, the aptly named American bumble bee, is on the ropes. Among the threats to its survival: competition from honey bees.

Death’s come knocking a last time for the splendid ivory-billed woodpecker and 22 more birds, fish and other species: The U.S. government on Wednesday declared them extinct.

Tiny fragments from an asteroid could shed light on the early development of the solar system, thanks to the unique capabilities of Argonne National Laboratory.

There are hundreds of species of mantis shrimp — crustaceans measuring anywhere from 1-12 inches long. The peacock mantis shrimp, indigenous to the waters of Indonesia, has a specific trait that humans are trying to replicate. 

U.S. Steel is reporting that a “rusty colored” discharge that poured into Lake Michigan on Sunday from its plant in Portage, Indiana, was due to elevated iron levels.

Officials from the Indiana Department of Environmental Management are investigating a “rusty colored liquid” discharged from the U.S. Steel plant in Portage, spotted Sunday evening in the Burns Waterway.

It is the largest single-day volunteer effort in support of environmental stewardship. Here’s how to get involved in National Public Lands Day at Chicago area parks and preserves.

In what officials call a key step to combat climate change, the Environmental Protection Agency is sharply limiting domestic production and use of hydrofluorocarbons, highly potent greenhouse gases commonly used in refrigerators and air conditioners.

Capybaras, native to Central and South America, are the largest members of the rodent family, tipping the scales at 130 pounds. Three of them have just arrived at the Brookfield Zoo.

The National Weather Service is warning people to steer clear of parks, trails, piers and breakwaters Wednesday and Thursday, with waves as high as 18 feet and wind gusts up to 45 miles per hour in the forecast.

Two harbingers of autumn — the harvest moon and fall equinox — are occurring within days of each other this week, which will make for some interesting sunsets and moon rises. And keep an eye out for “Chicagohenge.”

Four space tourists safely ended their trailblazing trip to orbit Saturday with a splashdown in the Atlantic off the Florida coast. 

A wetlands restoration project is underway at Powderhorn Lake Forest Preserve in the Calumet region, where construction of a human-made water control device will recreate a more natural system of drainage.

The creation of the Native and Pollinator Garden Registry means Chicago gardeners now have protection from overzealous ticket writers. And plants like milkweed can take their rightful place alongside other “flowers” instead of being mistaken for weeds.