AILSA CHANG, HOST:
When frogs start disappearing from a place that they've been in for decades, it can be a warning sign for the whole ecosystem. In Indiana, nature lovers and scientists are raising the red flag for the crawfish frog, a species that's been on the decline. WNIN's Tim Jagielo has this report on efforts to bring the at-risk amphibians back to their historic home.
(SOUNDBITE OF FROGS TRILLING)
NATHAN ENGBRECHT: So that high-pitched trilling sound that you hear, that's a forest frog, a very small type of tree frog, a western chorus frog. I think I hear a little chuckle, which would be a southern leopard frog.
TIM JAGIELO, BYLINE: Indiana Department of Natural Resources's state herpetologist Nathan Engbrecht is standing near the vernal pool, a temporary breeding pond full of amphibians trying to find mates.
Do the crawfish frogs - well, they're not going to - we're not going to hear them, but...
ENGBRECHT: We won't hear them today.
JAGIELO: Yeah.
ENGBRECHT: But they are calling this time of year. This is their mating season, and so they have a loud snore of a call. It's actually quite impressive.
JAGIELO: If all goes well, the loud, impressive call of the crawfish frog might return to this pond in 2026, 39 years after they disappeared.
(SOUNDBITE OF BUCKETS RATTLING)
UNIDENTIFIED PERSON #1: Hi.
JAGIELO: Engbrecht and assistant Jason Mirtl are part of a conservation effort to bring the endangered crawfish frog back to southwest Indiana's Angel Mounds State Historic Site. This is done by moving crawfish frog eggs in from another area.
ENGBRECHT: So our measures for success in terms of how do we know when they've gotten here is when they can actually mate and start laying their own eggs and they become more self-sustaining.
JAGIELO: These frogs are about fist-sized and live in and near empty crawfish burrows. They have golden or black circles covering their body. Local naturalist Mike Lodato has closely studied the frog populations since the 1970s.
MIKE LODATO: There were several populations in this vicinity in this part of the state. They've slowly disappeared over the years. Most of them are explainable because of urbanization or highway construction or surface mining, something like that. This population disappeared for unknown reasons about 1987 or so.
(SOUNDBITE OF FOOTSTEPS)
JAGIELO: Everyone drags buckets of frog eggs to the water's edge. Engbrecht says this temporary springtime pool is actually the original crawfish frog breeding pond for this area.
ENGBRECHT: ...Pond. So we're back at ground zero here in Angel Mounds to put these eggs in. And this is just the type of wetland that crawfish frogs like to use. Dries up in the fall, fish can't get established, kind of resets itself, fills back up in winter and spring.
JAGIELO: Healthy amphibian populations migrate to such pools in the spring to breed. The Department of Natural Resources is trying to kick-start the process.
ENGBRECHT: It's not super deep, but I want those eggs to have at least some sunlight that can come down on them.
(SOUNDBITE OF WATER SPLASHING)
JAGIELO: The clear, cool water is about knee-deep. Everyone wades out, one bucket at a time.
(SOUNDBITE OF WATER SPLASHING)
UNIDENTIFIED PERSON #2: (Inaudible).
UNIDENTIFIED PERSON #3: One at a time.
JAGIELO: Engbrecht lifts the jiggly mass of eggs, gently setting it atop foliage just under the water's surface. They repeat this in a few different spots, placing a wire cage over them.
ENGBRECHT: ...Around them, and that'll give them a little bit of protection. And once they hatch, in probably about a week or two, then the tadpoles will be swimming around the wetland. We'll pull the cages off, and then the tadpoles are on their own for about the next three months.
JAGIELO: Engbrecht hopes they complete the tadpole stage by the time the pool dries up and return next spring to breed.
ENGBRECHT: For us, you know, it's just kind of a part of our mission for managing healthy fish and wildlife populations. But on a personal level, I really like these frogs, and I'm really hoping to get them back here at Angel Mounds where they were, you know, in the past.
(SOUNDBITE OF FOOTSTEPS)
ENGBRECHT: You good, Mike?
LODATO: Yep.
JAGIELO: For NPR News, I'm Tim Jagielo in Evansville, Indiana.
CHANG: And in the past few weeks, Engbrecht says the tadpoles have hatched, and they are doing just fine.
(SOUNDBITE OF MAJ TOURE'S "CONSCIOUS LOVE") Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
