cacti are a key species in the ecology of the Galapagos Islands, the pads forming a major food source for tortoises and land iguanas, and the fruits being eaten by iguanas, doves and mockingbirds. The flowers, fruits and seeds are eaten by cactus finches, which may also obtain water by pecking at the fleshy pads (3) (9). In return, these species help to disperse the seeds of the cactus, and also act as important pollinators of the flowers, particularly on islands lacking insect pollinators such as bees (3) (9) (11). Flowering of Opuntia echios
has been reported to occur between November and February, with each plant producing a few flowers every day throughout the flowering season. The seeds take several months to mature, and the long flowering season means that the fruits ripen over a period of time rather than simultaneously (11). The species may also be able to reproduce vegetatively (3), an entirely new individual growing from a detached portion of the plant. It is thought that the Opuntia
species of the Galapagos Islands are very long-lived, potentially reaching ages of 150 years or more (8).