Photo by Barry Wicklow.
Biologist Barry Wicklow spotted this gray treefrog (Dryophytes versicolor) nestled against the greenish foliose lichen (Parmelia sulcata) on a tree during an aquatic ecology study. “These frogs are remarkable for their adhesive toes, freeze tolerance, and astonishing ability to change color depending on their environment,” Wicklow said. “I’ve observed gray treefrog colors ranging from nearly white to shades of mottled gray, brown, and green. The frogs control these camouflage colors by expanding or contracting skin cells called chromatophores: melanophores (dark brown/black melanin), xanthophores (yellow/orange pigments), and iridophores, which reflect and scatter light. Color changes to match their environment take only minutes.”