Airdate: Apr 03, 2001
Scientist: John Serrao
American Toads: Cross the Road
Why did the toad cross the road? Turns out he had a very compelling reason.
music; ambience: American toads, trilling
Why did the toad cross the road? Turns out he had a very compelling reason. I'm Jim Metzner, and this is the Pulse of the Planet. When you hear this trilling near woods and ponds, you know that it's breeding season for American Toads. But in order for nature to take its course, the toads need to be in their breeding grounds.
Naturalist and author, John Serrao: "Toads are only in the water for a couple of days every year to fertilize their eggs, and then they leave the water and go back in the woods. Unfortunately, because it is only for a short period of time that the toads are reproducing in the water they all do it at the same period of time, and if there's a road that interrupts that journey to get to their breeding pond, they all cross the road at the same time it seems, in the same night it might be, one night, when it's the right temperature, the right humidity, the toads all come out of hibernation sometime usually in April, and all cross the road at the same time, and one time last year I counted almost a hundred toads on a one mile stretch of road that were trying to cross the road, and out of those hundred toads, sixty of them were killed by cars. So you can imagine the mortality rate on these toads, and that wasn't even a busy road. You can imagine how many toads get killed crossing the road to get to the breeding pond on that one or two nights of the year when they come out to go into the water, and there are some places in the northeast where they have actually built culverts under the roads at these important places between the woods and the breeding pond so that these amphibians don't have to cross the road, they go underneath the culvert instead, and some roads in some places in New England are actually closed during that very crucial period of the year when these amphibians are crossing."
Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.