"Toad Tunnels" Built to Help Amphibians Cross Roads
for National Geographic News
April 15, 2005
Later this month, when the next warm, wet rain soaks the northeastern U.S., it will signal thousands of American toads to hop to their breeding ponds. To get there, many of the toads will cross roads that slice through their habitat.
John Serrao, a naturalist in Pennsylvania's Pocono Mountains, says that unless Buffo americanus and other amphibians get help crossing the road, their local populations will disappear.
Entire populations of American toads breed within the same few days at the same time each year, usually late April or early May.
According to Serrao, the toads hop to their breeding ponds after the ground has warmed, the air temperature stays above 65° Fahrenheit (18° Celsius), and the first hard spring rain falls.
"To get to their ancestral breeding ponds, a lot [of toads] have to cross roads," Serrao said. "And they're slow moving at that time of year—it's still cool, they've been inactive—and they get squashed."
Read more here