Documentary
The Call of the Swamp, Bird-Voiced Tree Frog
TL;DR
A fifteen-minute documentary about the bird-voiced treefrog, an amphibian that lives in the swamps of seven Illinois counties. It came out of a research project in 2023 and is free to watch on YouTube.
Quick Facts
- Full premiere title
- The Call of the Swamp, Investigating the State-Threatened Bird-voiced Treefrog
- Year
- 2023
- Runtime
- 15 minutes 4 seconds
- Made by
- National Great Rivers Research and Education Center with Route 3 Films
- Premiere
- November 15, 2023, The Old Bakery Beer Company, Alton, Illinois
- Where to watch
- YouTube, posted December 2, 2025
The Call of the Swamp follows scientists from the National Great Rivers Research and Education Center into the bottomland swamps of southern Illinois, looking for a frog that whistles like a bird. Jessica Mohlman led the project, and Route 3 Films, a video production company in St. Louis, shot it. It premiered on November 15, 2023 at The Old Bakery Beer Company in Alton, and Route 3 Films posted the full version publicly on December 2, 2025. Mohlman has said she wants people to know that this species and its habitat both need help.
Why OGSP Recommends It
One Good Story Project recommends The Call of the Swamp because it introduces viewers to a threatened animal few people even know exists. The 15-minute documentary follows Jessica Mohlman and the National Great Rivers research team into southern Illinois’s remaining bald cypress and tupelo swamps, where they study the bird-voiced treefrog and the habitat it needs to survive.
The film gives a peek into what field research looks like and why protecting these frogs and wetlands matter. Originally released in 2023, the full documentary is now available to watch free on YouTube.
Related Resources
Key Takeaways
- The bird-voiced treefrog has been listed as Threatened in Illinois since 1998.
- It lives only in remnant bald cypress and tupelo swamps in seven southern Illinois counties.
- Adult males measure 1.1 to 1.5 inches, and the call is a run of ten to twenty birdlike whistles.
- Interns set fifty pipe traps at each of ten swamp sites, five hundred in all, and checked them weekly for four weeks.
Frequently Asked Questions
What is The Call of the Swamp about?
It follows researchers into the bottomland swamps of southern Illinois as they look for the bird-voiced treefrog, an amphibian listed as Threatened in the state since 1998.
Who made The Call of the Swamp?
The National Great Rivers Research and Education Center made it with Route 3 Films, a video production company in St. Louis. Jessica Mohlman led the project.
Where can I watch The Call of the Swamp?
Route 3 Films posted the full fifteen-minute version on YouTube on December 2, 2025, and it is free to watch there.
What is a bird-voiced treefrog?
A small amphibian whose call is a rapid run of ten to twenty birdlike whistles. Adult males measure 1.1 to 1.5 inches and females a little more.
Why is the bird-voiced treefrog threatened in Illinois?
Its colonies have been cut off from each other as bottomland hardwood swamps were drained and lost. Flooding, drought and ranavirus are also named as concerns.