The Effects of El Nino

In early 1998 David Parer returned to the Galapagos for three months to complete "Islands of the Vampire Birds" at the height of the biggest El Nino ever recorded - an event that occurs every 5 to 10 years.

For eight months it poured constantly and in that time Galapagos received 10 times its usual rainfall. Sea temperatures rose to 31°C - 5°C above their normal level, the temperature of a warm bath!

The vast schools of anchovy and sardines - the normal power house of the archipelagos' huge seabird populations - departed and large numbers of animals died. Most of the marine iguanas, sealions and fur seals perished. In some areas 90% of the corals bleached white and many died, their symbiotic algae driven from the corals. The once rich oceans surrounding the Galapagos became a desert.

In contrast, the islands became a burgeoning green jungle. Where once dry watercourses bisected the lava slopes of the volcanoes, raging rivers thundered to the sea. On one trip along the western side of Floreana Island David Parer filmed lines of waterfalls cascading into the sea off the 30m high cliffs. Beds of wildflowers flourished, host to butterflies and carpenter bees. And Darwin's finches bred in their thousands.

The Wolf Island vampire finches gave up their diet of blood and fed on the abundant seeds. On Daphne Island, site of a 25 year study of the finches by Peter and Rosemary Grant, the finch population increased 10 fold to 4,000. As long as the good times lasted the finches bred, some individuals raising as many as 6 clutches in 12 months. They were so numerous that the early morning bird chorus sounded like a football crowd at the Melbourne Cricket Ground.

Erratic weathers patterns spread over just a few years are the hallmark of the Galapagos environment and they can produce major natural selection changes in the finches over just a few generations. After 25 years of intensive study of a complete population of finches on Daphne Island, the Grants were able to witness and measure rapid changes in the beak size within a single species, so proving Darwin's theory of evolution in action for the very first time.

The Grants are doing what Darwin could not do, going back to the Galapagos year after year; and the Grants are seeing what Darwin did not imagine could be seen at all.