As herbivores, Galapagos tortoises munch on grasses, leaves, flowers, and fruits — and are particularly fond of prickly pear ...

After hunting, a Nazca booby returns to its nest near a thicket of prickly pear cacti on Isla Wolf. Scientists have been studying the birds elsewhere on the islands to gauge how long-term changes ...

But over at Isabela Island, the dominant plant is the prickly pear cactus, a delicacy to giant tortoises. Some biologists have suggested the cactus adapted to this threat by growing taller ...