Nakili, the eastern black rhinoceros. (Jim Schulz / CZS-Brookfield Zoo)

Nakili was diagnosed with kidney disease last summer. At 33 years old, he was the oldest male of his species living in an accredited North American zoo.

A bur oak, estimated at 250-300 years old, is dismantled at Lincoln Park Zoo, May 2, 2023. (Patty Wetli / WTTW News)

Lincoln Park Zoo said farewell today to a 300-year-old bur oak, but the tree will live on in multiple ways.

The red-winged blackbird was among the most observed species in Chicago for the 2022 City Nature Challenge. (Susan Young / Flickr Creative Commons)

It's time for the annual City Nature Challenge, a friendly global competition among hundreds of cities, running from Friday through Monday. Here's how to submit nature observations and boost Chicago in the standings.

Eaglet heads poke above the top of their nest. (Will County Forest Preserve / Chad Merda)

After months of great eggs-pectations, the Forest Preserve District of Will County has announced the arrival of five baby bald eagles.

(Danne / Pexels)

Scientists calculated the biomass of various groups of mammals, and humans’ impact weighs heavily on the planet.

Construction on the Rockford Airport cargo expansion has come right to the edge of Bell Bowl Prairie. (Courtesy of Cassi Saari)

Barring any last-minute court decisions, the Greater Rockford Airport Authority will soon resume construction on its cargo expansion project, bulldozing a portion of ancient Bell Bowl Prairie in order to carve out a new roadway.

A bald eagle is pictured in a file photo. (U.S. Fish and Wildlife Service)

Forest Preserve District staff and volunteers have been keeping a close eye on the nests of two mated pairs of eagles and recently confirmed that at least one of the couples is sitting on eggs.

Native bergamot seed heads. (U.S. Fish and Wildlife Service Midwest / Courtney Celley)

A new report highlights several supply-and-demand conundrums and makes recommendations for how to increase native seed production.

John James Audubon's illustrations are still revered, but the naturalist's troubling history is being called into question. (Biodiversity Heritage Library)

As a more complete, and complex, portrait has emerged of John James Audubon, birders and ornithologists have struggled to reconcile their missions with the troubling aspects of his legacy: buying and selling slaves, plagiarism and the exploitation of natural resources.  

Orland Grassland, a thousand-acre restored prairie. (Patty Wetli / WTTW News)

“There are places you walk where you see sky touching the earth, and you can imagine this as the gateway to the Grand Prairie,” site steward Pat Hayes said of Orland Grassland.

Bison are the largest land mammal in North America. (U.S. Fish and Wildlife Service Midwest Region)

New research shows bison are altering the landscape in unexpected ways when reintroduced to Midwest prairie ecosystems. 

(Pixabay)

Headlines spun out of control when it came to new research results on the Earth’s core. In other news, narwhals have had it with noisy neighbors.

(Jacub Gomez / Pexels)

Looks like we’re going to have to come up with replacements for terms like “starstruck” and “starry-eyed.” Scientists say the visibility of stars is rapidly fading as light pollution increases.

(U.S. Fish and Wildlife Service Midwest Region)

A GPS collar allowed researchers to track the wolf from Michigan all the way to Manitoba, Canada. That's just one of the wild stories we followed this week.

Zebra shark. (Brenna Hernandez / Shedd Aquarium)

From industrious sharks to the bird of the year, here’s what caught our attention this week on the climate and nature beat.

(Yanna Zissiadou / Unsplash)

Openlands is hoping to find more Latino and Spanish-speaking volunteers to lead the Birds in My Neighborhood program, which educates kids on native birds through in-school lessons and field trips.