galapagos

The Galápagos archipelago forms a unique ecoregion straddling the equator approximately 1,000 km west of Equador. There are 13 large islands and 115 smaller ones with a total land area of 7,882 km2. The islands are volcanic in origin with the oldest being formed between 3 and 6 million years ago and the youngest islands in the west still being formed. Most of the islands are the peaks of volcanoes and volcanic activity has shaped the characteristics of the islands such as the soils.

The islands are also found at the intersection of major ocean currents which shape the biogeography of the area partly by affecting rainfall patterns on the islands and from upheavals of plankton caused by the Humbolt Current. This influx forms the basis of the marine food chain for many unique species such as the marine iguana, Galapagos penguin and flightless cormorant.

The islands have gained an iconic status for their unique wildlife and for the role in shaping Charles Darwin’s research by evolution and natural selection. Many of the islands share similar species groups that evolved to match the specific conditions of each island. For example there are 13 species of Darwin’s Finches which show remarkable specialisations to exploit different ecological niches. Each of the finch species shows distinct behaviours and physical characteristics such as beak structure. There is also a rich endemic biodiversity on the islands, for example 20 of the 22 reptile species found there are found no where else.

There are not so many land bird species on the Galapagos but 24 of the 29 found there are endemic. This level of endemism means that the biodiversity is vulnerable to human impacts. Almost the entire archipelago has protected and humans are only able to live on the largest five islands, however these are the ones with the richest biodiversity. As within other oceanic islands introduced species such as cats, rats, and cattle have had a major impact on species and remain very difficult to remove.

Currently Durrell’s work in the Galápagos is focussing on the conservation of the mangrove finch, which is the most restricted member of the Galápagos archipelago’s remarkable Darwin’s finches. This finch has evolved from a common ancestor to specialise in the small and highly localised mangrove forests. The mangrove finch is the rarest vertebrate in the islands and has one of the most restricted distributions of any bird in the world: it is threatened by a collection of non-native and invasive animals. In 2006 Durrell, with significant funding from the UK’s Darwin Initiative, formed a partnership with the Charles Darwin Foundation and Galápagos National Park to arrest the decline of the Mangrove Finch and eventually restore the population to areas of mangrove from where it has disappeared.