Conservation scientist Jacob Kubel with the blue leopard frog, rare compared with green and beige specimens.
Late this summer, Jacob Kubel, a conservation scientist with the state Division of Fisheries and Wildlife's Natural Heritage and Endangered Species Program, was slogging through a Sudbury wetland, searching for a new species of leopard frog, when something unusual caught his eye.
"The frogs were quick and blended in with their surroundings," Kubel said in an e-mail, "so we were basically chasing blurs and moving vegetation."
Leopard frogs, which are named for their dark spots, are usually green, beige, or some combination of those colors, but one of the blurs Kubel saw through the stems of sedge and grass appeared to be bright blue.
"I couldn't be sure of the exact color," said Kubel, "so I just thought to myself, 'Oh, I have a brightly colored one here - he should be easier to chase down.' "
Kubel said he didn't think much of it at first: Individual animals in many wildlife species, after all, vary greatly from one another. But when he captured the 2-inch frog and looked at it up close, he realized it was something he - in fact, most everyone - had never seen before: a blue-colored leopard frog.