Birdwatchers everywhere are in a bit of a flap.
A photograph of a bird with a visible egg inside its body has been taken for what is believed to be the first time ever.
A team of experts had visited a remote Indian Ocean tropical island to study the critically endangered Mascarene Petrel.
A photograph of a bird with a visible egg inside its body has been taken for what is believed to be the first time ever. The critically endangered Mascarene Petrel was being studied by scientists at Reunion Island in the Indian Ocean when the amazing picture was taken
Unlike land birds, some sea-birds have feathers which hug their body more to stop them getting wet - thus making the bump better defined (left). Pictured right, a file photo of the rare Mascarene Petrel
Little is known about the elusive sea-bird - but what the researchers came back with is an image of a clearly gravid (ie egg-carrying) member of the species in flight.
The picture showing the obvious egg bump has given researchers fresh insight into the timing of the petrel's breeding season on Reunion Island, the bird's only known habitat.
The discovery was described in the latest Bulletin of the British Ornithologists' Club.
'Against the background of a pinkish-orange sunset, with Reunion Island in the distance, I spotted a petrel through my camera's viewfinder.
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Share'Almost immediately I saw the outline of an egg, a huge bump at its belly. I called out to the other expedition members - "She has an egg, she has an egg..."', said author Hadoram Shirihai.
'She flew close to the boat which gave me the unique chance to photograph her just before the sun set.
'It was a magical moment, and to think that in less than an hour she would probably lay her egg and contribute to the future survival of this threatened species.'
The picture showing the obvious egg bump has given researchers fresh insight into the timing of the petrel's breeding season on Reunion Island (above), the bird's only known habitat
In total, the researchers studied 33 Mascarene Petrels and photographed 12 of them.
But it was only due to a series of coincidences that the image came to light.
Unlike land birds, some sea-birds have feathers which hug their body more to stop them getting wet - thus making the bump better defined.
Furthermore, the petrel was in flight - making it even easier to spot.
And finally, it also helped that the petrel's eggs are 'disproportionately huge'.
Most extraordinary of all is the fact the picture was of an extremely rare bird - something which has astonished BirdLife International, the conservation group that released the picture and compiles the official Red List of endangered birds.
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