Where we take a moment to explore some of the unique and impressive species that call the Great Lakes home. Sun-gazer. Squirrel of the marshes. Smallest heron in the Americas. Measuring about a foot in length and weighing in at less than 4 oz., the least bittern is widely spread but rarely seen.
Least bitterns make their homes among the reeds of dense wetlands. Even with a migratory range from southern Canada to northern Argentina, the bittern remains elusive, making it hard for wetland managers to get an idea of their numbers.
Migrating to the Great Lakes each summer to breed, least bitterns fly only at night. And as if that didn’t make visual identification difficult enough, they also prefer to flee from predators and approach their nests on foot. On top of it all, least bitterns are well camouflaged. When threatened, the bird will freeze and point its head upward, exposing vertical striping on its throat that allows it to blend in with its surroundings—thus the nickname “sun grazer.” They will even sway in the breeze to match the motion of the reeds.
Elusive as they are, least bitterns are more often heard than seen—a low cooing from the males and a ticking from the females is the best way to “spot” them. Nests are made by constructing platforms of reeds above the water. Even these are camouflaged. A canopy of surrounding marsh plants is crimped in place above the nest. But the 4-5 eggs laid every season won’t be in the nest for long. Over the span of roughly 50 days, the chicks will hatch, fledge, and leave the nest to start hunting on their own.
Like squirrels leap from branch to branch, least bitterns walk among the reeds 2-3 feet above the water, allowing them to hunt in areas well outside the wading range of larger birds. Balancing on a reed, they strike down with their long bills to catch their prey. Their diet consists of fish like minnows and perch, insects, frogs and other small amphibians, invertebrates, crayfish, and even mammals like shrews and mice.
We’ll have more species spotlights in the coming weeks. In the meantime, check out our spotlight on lake sturgeon.
Four science educators from Illinois and Indiana have been selected for the 2025 Shipboard Science Immersion on Lake Michigan July 7-13. The educators will spend a full week alongside researchers aboard the EPA research vessel Lake Guardian. Afterwards, they will bring Great Lakes science back to their classroom.
Learn more and meet the four incredible teachers representing Illinois and Indiana at the link in bio.
🌿 Educators—Explore Restoration in Action! Join us Thursday, July 31 at Purdue Northwest (Hammond, IN) for a FREE full-day workshop diving into the transformation of the Grand Calumet River Area of Concern. 🚍 Tour restored sites 🧠 Engage with VR curriculum 📚 Earn 6 PD hours 🥐 Breakfast & lunch included 🔗 Register now at the link in bio and bring real-world science to your classroom.
Attention STEM educators! Our new aquaponics curriculum is here! Designed for 9-12th grade classrooms with operating aquaponics systems, this curriculum, created by educators for educators, teaches STEM concepts through the lens of aquaponics, aligning with NGSS and Great Lakes Literacy Principles. Learn more at the link in bio.
Big news from Illinois‑Indiana Sea Grant! We’re thrilled to announce Dr. Stuart Carlton, our Assistant Director since 2018, will step into the Director role on July 14, 2025. Join us in congratulating Stuart, and read on at the link in bio to find out more about the transition!