PICTURED: The prehistoric-looking great white pelican with a 7ft wingspan and gigantic beak

Wildlife photographer Karl Terblanche, who took this picture, said: 'As the boats leave the harbour, the pelicans come swooping down. They seem to know there's always fish on board to feed the seals further up the bay.'

Giant: A great white pelican flaps its enormous wings over Walvis Bay in Namibia

Karl has captured, in extraordinary detail, the unusual features of this prehistoric-looking bird, from the pink tip of its beak to the inky points of its webbed feet.

He said: 'I was on a speedboat with about 15 other tourists. Everything just came together at the right time. It was also a beautiful bright day but with enough cloud cover which helped get the right exposure.

'The bird came very close. At the very most it was only ever a metre away. The bird followed us for around five minutes and we probably fed it about two fish.'

The pelican uses its leathery lower pouch as a net. It plunges its bill into the water and trawls for fish.

The pouch can hold up to 38 pints  -  heavier than the bird itself, proving that American newspaper editor Dixon Lanier Merritt was right when he wrote in a limerick in the 1900s: 'Oh a wondrous bird is the pelican!/ His bill will hold more than his belican.'

Although large, pelicans are relatively light as their pneumatic bones contain air spaces, meaning the skeleton weighs less than the feathers.

Thought to have appeared in the dinosaur era, they are not capable of sustained flapping flight but can stay airborne for 24 hours and travel 850 miles without resting, gliding at up to 35mph on thermals at heights of 4,000ft.

Long held as symbol of charity and self-sacrifice, pelicans were once thought to care so much for their young that in a drought they would pierce their breast and feed them blood.