Mass Frog Emergence in Georgia’s Lee County
June 14, 2013
Chief County Marshall Jim Wright was checking the site near Leesburg last month when he saw thousands of the largest tadpoles he’d ever seen. That sight was topped a few weeks later when he returned to find the tadpoles metamorphosing en masse.
Frogs, many still sporting tails (left), crowded the bank, covering an area 10-15 yards long.
How many frogs where there? Wright didn’t hazard a guess. “All I know is there’s a lot of frogs down there. It’s amazing.”
John Jensen, a senior biologist with Georgia DNR’s Nongame Conservation Section, was also amazed. After reviewing photographs, Jensen said Wright witnessed a massive, synchronous emergence of river frogs: thousands of tadpoles changing into frogs at the same time.
Such events are sometimes seen with toad species that develop quickly, but less so with frogs, because their tadpoles develop at differing rates depending on how much individuals eat and other factors.
Jensen said the mass emergence of river frogs – the first he had heard of – was made more possible because tadpoles of this large Coastal Plain species tend to school together, feeding at the same time on the same things, which could keep their development on a similar pace.
Still, the odds of the emergence that Wright documented are low. It can take a year for a river frog to go from egg to mature frog.
“I think they just … all developed at the same time, and they were ready to come out,” said Jensen, who helped author “Amphibians and Reptiles of Georgia.”
Wright checked last week and the frogs had not yet dispersed into the swamp. However, they were more scattered. The first time he saw the frogs they appeared almost in rows, each facing up the bank.
“It looked like they were all looking at a movie theater,” Wright said.