A visit to Galapagos is all about seeing and experiencing nature at close quarters; not only wildlife including birds, but also geology and the evolutionary forces working almost visibly behind the scenes. Given its isolation 1,000kms off the South American continent, the development of the islands has been shaped by geology, climate and currents in such an evident fashion that Galapagos is considered an evolutionary laboratory.

The Galapagos, volcanic in origin and formed about 3-5 million years ago, is one of the world's areas of greatest volcanic activity. More than 50 eruptions have occurred in the last 200 years, with activity concentrated in the western islands of Fernandina and Isabela where fumaroles can be seen rising in the air. Geologically the Galapagos islands are very young and in active development.

The climate is a key factor behind the islands' unique development. In particular, given the islands' distance from the mainland, weather is determined by ocean currents, in turn affected by winds. Galapagos is the meeting point of several currents, mainly the cold Humboldt Current from the south and the much warmer Panama Current from the north. From July to December the trade winds blow the Humboldt Current towards the Galapagos, so the result is a cool climate, an inversion layer which frequently produces a fine mist or garua, and dryness. This is the dry season. From January the trade winds disappear, and the Panama Current then dominates to produce warmer waters, and more normal tropical weather.

The islands' unique wildlife has been shaped by the climate and the islands' isolation. Once there, wildlife has evolved in response to the climate without influence from the mainland, and without being able to influence the mainland. This accounts for the exceptionally high number of species unique to the islands - ie endemism. One third of the 600 plant species, a fifth of the inshore fish of 400 fish species, and more than three quarters of the land-based animals (which include 58 resident bird species, 22 reptile species, and 6 mammals) are endemic. And many species are only found on one or a few of the Galapagos islands, as described by Darwin:-

"By far the most remarkable feature in the natural history of this archipelago.... is that the different islands to a considerable extent are inhabited by a different set of beings. I never dreamed that islands, about fifty or sixty miles apart, and most of them in sight of each other, formed of precisely the same rocks, placed under a quite similar climate, rising to a nearly equal height, would have been differently tenanted...." Charles Darwin 1845