Once they were one of the most abundant species of bird in North America living in enormous flocks and migrating en masse to such an extent they would blacken the sky.
Today Passenger Pigeons are no more even though it's estimated that there were once as many as five billion of them. The colourful birds were hunted to extinction and also a victim of habitat loss.
The 19th century saw the demise of the bird and then the last authenticated sighting of a wild Passenger Pigeon was in Ohio in 1900. Fourteen years later Martha – the last living captive bird – fell off her perch and died in Cincinnati Zoo.
Now the bird can be seen again at the University of Aberdeen's Zoology Museum which has just taken delivery of a stuffed specimen.
Dr Martyn Gorman, Head of Zoology at the University and Honorary Curator of the Zoology Museum, said: "Museums are now the only places you will see a Passenger Pigeon, but even they don't have very many specimens. As the bird was once so common, people didn't think it was important to have them in museums. By the time that people began to collect them they were already very, very rare.
"The University of Aberdeen's Zoology Museum is therefore extraordinarily fortunate in having just acquired a specimen of this enigmatic species."
Not much is known about how the bird came to be in Scotland.
Dr Gorman added: "It was discovered in a box of old bird skins by local taxidermist Stephen Caine around eight years ago. Stephen refurbished the mounted bird and it was then acquired by the late Dr Robert Ralph whose wife Ann kindly donated it to the museum.
"This is a most valuable and important addition to our museum which was recently awarded the status of a recognised collection of national significance.
"We are deeply grateful to Dr Ralph and his wife for this most generous of gifts and we hope that it will educate our students and the general public about the dangers of extinction."
The Zoology Museum, within the University's Zoology Building on Tillydrone Avenue, is open to the public Monday to Friday, 9.00am-5.00pm.