Exposure to sulfur-rich volcanic soil may increase production of pheomelanin, a pigment that gives a reddish tint to the feathers of barn owls living on remote volcanic islands Barn owls (Tyto alba) ...

For several years Paris-based photographer Olivier Grunewald has been documenting the Kawah Ijen volcano in Indonesia, where dazzling, electric-blue fire can often be seen streaming down the mountain ...

There are many sulphur (yellow) butterflies in southern Florida and, lucky for us, they are present all year round. The most abundant of the sulphur butterflies are the orange barred sulphur, the ...