Wildlife Photographer of the Year: Blood-loving birds of the Galápagos

“Wolf Island is truly wild,” says Thomas P Peschak, winner of Wildlife Photographer of the Year 54 Behaviour: Birds category.

The isolated island, located in the northwest of the Galápagos archipelago in the Pacific Ocean, is often shrouded in mist. Its rocky cliffs are exceptionally steep and there’s no permanent freshwater source.

“This is a harsh place to survive, unless you are a seabird which can get food from the rich adjacent ocean,” he explains.

But finches aren’t seabirds and instead of a seafood diet, these small birds have to utilise other resources in their unforgiving environment. In the video below, Dr Alex Bond, our Principal Curator of Birds, explains the most extreme feeding strategy of all of Darwin’s finches.

The vampires of Wolf Island

Nazca boobies, Sula granti, are abundant on Wolf Island – also known as Wenman Island – using it as a breeding ground. They feed by diving at high speed into the surrounding ocean to capture small fishes. When they return to the island, they live in large colonies and nest amongst the dense cactus thickets.

But survival on Wolf Island is tougher for the ground finch species, Geospiza septentrionalis. These small birds are unable to leave the safety of the plateau to find food. The island also lacks a permanent water supply and rarely experiences rain.

This finch species is also resident on Darwin Island, one of the smallest and the most north-westerly of the Galápagos Islands.

Galápagos finches are well-known – they’re sometimes called Darwin’s finches as they were first studied by the famous biologist Charles Darwin during his voyage aboard HMS Beagle in the 1830s. Darwin’s finches are a group in which each species has specially adapted beaks and behaviours to aid survival in their specific habitats, but are all descendants of a common ancestor.

The finches on Wolf and Darwin islands feed on seeds and insects. But their supply often runs out, especially during the dry season. This leaves them in need of another source of nutrition.

Finches may have once pecked at the feathers of Nazca boobies and other seabirds to feed on parasites, but this trait has developed into one that is unique to G. septentrionalis.

“They’ve become vampires,” says Thomas. “I’ve seen more than half a dozen finches drinking from a single Nazca booby.”

The finches peck at the base of the seabirds’ feathers until blood begins to flow, which they then lap up with their tongues. This behaviour has resulted in the common name of vampire ground finches.

The boobies appear tolerant of the vampire birds’ behaviour, however. The beak-inflicted wounds and blood loss don’t seem to cause the seabirds any significant or lasting damage.

A challenging location

Thomas captured his award-winning image, Blood Thirsty, on the isolated Wolf Island, which is the partial remains of an extinct volcano. The island was named after Franz Theodor Wolf, a German naturalist who studied the Galápagos Islands in the late-nineteenth century.

Wolf Island is so remote – and its cliffs so dangerous – that it’d never been landed on until 1964, and only with the aid of a helicopter. There’s no permanent human population on the island and it’s rarely visited by rangers and scientists, although the surrounding ocean is highly regarded for its dive sites such as El Derrumbe.

The island itself is closed to tourists. Thomas managed to secure a rare permit to set foot on Wolf Island thanks to his work on a Galápagos climate-change story.

Thomas originally trained as a marine biologist specialising in human-wildlife conflict. But he turned to photojournalism, finding images able to create a greater conservation impact.

He’s now a National Geographic photographer, specialising in documenting the beauty and fragility of the oceans, islands and coastlines. Working alongside Non-Governmental Organisations, Thomas has been able to effect change, for example the protection of Hanifaru Bay in the Maldives’ Baa Atoll through his photography of its abundant manta rays.

Thomas is a veteran of Wildlife Photographer of the Year. In 2015 he was a finalist for The Wildlife Photojournalist Award with his image, The Shark Surfer and he won the Wildlife Photographer Portfolio Award in 2017 with a series of images captured in the remote Aldabra Atoll in the Seychelles.