Posted by: Andrew Haynes5 AUG 2014
Monday 1 September 2014 is the centenary of the death of a lonesome pigeon called Martha. Who cares about bloody pigeons, you may ask. Disease-carrying vermin, aren’t they?
But Martha was no ordinary pigeon. For 12 years she had lived alone in Cincinnati Zoo as the last surviving North American passenger pigeon (Ectopistes migratorius). Her death meant the extinction, after a scarily rapid decline, of a species that only 50 years earlier had numbered up to 5 billion and had probably been the world’s most abundant bird.
Fossil records show that the passenger pigeon existed 100,000 years ago in the Pleistocene era, with a range extending right across North America. It has been estimated that by the early 19th century the species accounted for 25–40 per cent of all birds in North America.
Passenger pigeons nested in huge colonies in deciduous forests around the Great Lakes. A single colony could cover hundreds of square miles, and single trees would often hold more than 50 nests (one was recorded with 317). The pigeons wintered mainly in alder swamps in the southern states of the US, where they migrated in enormous flocks. In 1866, one flock was described as being a mile wide (1.5km) and 300 miles long (500km). It took 14 hours to pass overhead and was estimated to hold more than 3.5 billion birds.
Despite those huge numbers, the species was doomed. In the 19th century pigeon meat was commercialised as a cheap food for slaves and the poor, resulting in hunting on a massive and mechanised scale. Pigeon numbers had already had begun to fall because of habitat loss arising from mass deforestation by settlers. After a slow decline between about 1800 and 1870, numbers fell catastrophically over the next 20 years. Before the scale of the loss could be appreciated, it was too late. When numbers dwindled to a few thousand, the birds stopped nesting. Attempts at captive breeding failed miserably.
When Martha died, her body was sent to the Smithsonian Institution in Washington, where it was skinned, dissected, photographed and mounted. Sadly, the institution then decided to entomb the taxidermised Martha in its archives rather than place her on display to remind the world of mankind’s destructive nature. At least, Cincinnatti Zoo has marked her significance by erecting a memorial statue.
It has been suggested that “de-extinction” of the passenger pigeon might be possible by cloning DNA fragments from preserved specimens, using other pigeon species as surrogate parents. But the extreme social nature of the species means that if any such project is to succeed it may require thousands of cloned individuals, which seems out of the question.