The Great Leopard Frog Invasion

Northern Leopard Frog from kingsnake.com user Terry Cox credit: kingsnake photo gallery 

In 1952 the tiny town of Oconto, WI woke up to hundreds of thousands, reports even go as far as millions, Leopard Frogs. Now being a Wisconsin Herper you would think I would have heard this odd little story before today, but I had not and that is why I am sharing it with you! Driving around today for my petsitting gig and my local NPR shared the story of the Oconto invasion. Seriously, it sounds like a herper's dream but it reminded me exactly how much of my life with animals is constantly spent simply learning new things.

In 1952, Lake Michigan was exceptionally high. Oconto is located on marshes near Green Bay and in spring when the lake rises, the marshes flood creating the perfect breeding habitat. When the waters receed as the summer comes, there is a natural loss to the eggs. This year however the lake never receeded from the marshes and well, the frogs had a great hatch rate. According to an article in the New Yorker Magazine from back then:

“A man I know,” continued the New Yorker reporter, “said they had besieged his house one night in what he swore was a highly organized way. He had gone out on his front lawn to have a look around with his flashlight and had been confronted by a million shining little eyes. He started toward the back yard and found that he had been outflanked. He swung the light around and discovered that the whole house was encircled. It was a scary thing to see, he said.” By morning they had departed for greener pastures, or puddles, and he was left to scoop them out of his basement window wells with a shovel. He took out two bushels.

That same article claimed that there were around "175 million frogs" that survived. Typically around 6% survival rate on wild frogs, so with the conditions being perfect with the high water in their habitat, that was exactly what happened. Regretfully this will never ever occur again due to extreme habitat loss. I spent a good two hours reading up on this so I will share some good links to save you the searching! Find them after the bump! So far, I still can't find photos and neither can anyone else really.  

Oconto Historical Society Page click here 

Milwaukee Magazine article click here

WUWM story that started the search listen here 

Discover Magazine article here 

The original New Yorker Article - this one does cost money, I didn't pay for it either but if anyone wants to - go here