Galapagos – in pictures

A Galapagos giant tortoise, an animal which can weigh up to 250kg, stares at the photographer from the crater floor of Alcedo volcano on Isabela Island while steam billows from an active vent behind. Photograph: Pete Oxford Photograph: Pete Oxford An estimated 15,000 giant tortoises roam wild in the Galapagos Islands where they are the dominant natural herbivore. Their appearance takes one back to the Jurassic Age where reptiles were at the apex of evolution. This photograph was taken on Isabela Island. Photograph: Pete Oxford Photograph: Pete Oxford/Pete Oxfrord A Galapagos shark patrolling the waters off Wolf Island. Photograph: Pete Oxford Photograph: Pete Oxford A pair of rapturous blue-footed boobies courts on Española Island. In trying to attract a mate, the male dances. If a female is attracted to him she will join him and together they will dance the "booby two step". Photograph: Pete Oxford Photograph: Pete Oxford Blue-footed boobies plunge-dive onto bait fish below. An endemic sub-species in Galapagos, they have stereoscopic vision, shielded nostrils (to prevent two jets of water hitting the brain) and a spongy, shock-absorbing tissue around the head and breast. Photograph: Pete Oxford Photograph: Pete Oxford An eroded tuff cone, known as Darwin's Arch, stands like a portal to Darwin Island, a mecca for scuba diving. Photograph: Pete Oxford Photograph: Pete Oxford A fever of golden cow-nosed rays swims in tight formation towards the mangroves and inner lagoons of Caleta Tortuga Negra, Santa Cruz Island. Photograph: Pete Oxford Photograph: Pete Oxford A great blue heron surveys its domain, ignoring the fact that it is in the main Galapagos town of Puerto Ayora on Santa Cruz Island. Photograph: Pete Oxford Photograph: Pete Oxford A marine iguana takes a stroll past the gift shops on Charles Darwin Avenue, Puerto Ayora, Santa Cruz Island. Photograph: Pete Oxford Photograph: Pete Oxford Marine iguanas bask in the sun to warm up sufficiently before entering the frigid waters of Cabo Douglas to feed on marine algae. Photograph: Pete Oxford Photograph: Pete Oxford An endemic Galapagos penguin glides through the water while hunting off Bartolomé Island. Photograph: Pete Oxford Photograph: Pete Oxford A young sea lion gives the taller waved albatross a wide berth on the beach at Punta Cevallos, Española Island. Photograph: Pete Oxford Photograph: Pete Oxford In a show of tameness for which the Galapagos is famous, a curious, young sea lion approaches a tourist at Gardner Bay, Española Island. Photograph: Pete Oxford Photograph: Pete Oxford Rivers of molten lava made the sea boil during an eruption of a parasitic cone of La Cumbre Volcano at Cabo Hammond, Fernandina Island, in 1995. Photograph: Pete Oxford Photograph: Pete Oxford Lava cactus, Santiago Island. Blue-footed Booby Day (17 June) is an annual fund-raising event. To find out more visit savegalapagos.org . Steppes Discovery is running a photography tour on an exclusive charter, led by wildlife photographer David Plummer. The trip departs 8 April 2012 and costs from £3,795pp. Photograph: Pete Oxford Photograph: Pete Oxford