Carolina Parakeets, the now extinct Pliocene relic

Most species of the avian family (Psittaciformes) that includes parrots, parakeets, and cockatoos are tropical and not well adapted to surviving sub-freezing temperatures.  But a formerly common bird, the Carolina parakeet (Conuropsis carolinensis) did live as far north as the shores of the Great Lakes, until overhunted to extinction–the last survivors dying between 1918-1930.  John Audubon kept a journal of his trip down the Mississippi River in 1820, and he reported large flocks of these colorful birds living in the river bottom swamps.  On one occasion he killed twenty for specimens he could use as models for his portraits.

Portraits of the extinct Carolina parakeet by John Audubon.  He used birds he killed as models for his paintings.

Carolina parakeets nested in colonies , laying eggs in hollow tree cavities.   Like the extinct passenger pigeon, they survived predation by producing more offspring than predators could destroy–a kind of overwhelming fecundity.  They couldn’t survive anthropogenic overhunting, however.  Farmers considered them pests because these seed-eating birds destroyed fruit to get at the kernels, and they swarmed over shocks of harvested wheat to eat the grains.  So the farmers killed as many as they could.  They were quite easy to massacre because of a fatal behavioral flaw.  When a hunter shot into a flock, the noisy birds would scream in alarm, take to the air, circle the area, and alight in the exact same place as the slaughter of a few minutes earlier.  Eventually, the flock would be completely destroyed.

In my book Georgia Before People I wondered why they hadn’t been saved from extinction by pet fanciers.  After reading Audubon’s journals, I can understand why.  Audubon wrote that they made “indifferent” pets.  Actually, from his description, it sounds like they made terrible pets.  They never learned to mimic human voices or pretty bird songs, but instead emitted an annoying loud and constant shriek.  Upon escaping a cage, they used their powerful bills to rip apart furniture, books, etc.

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The Pliocene (5 million-2 million years BP) was a much warmer epoch than the Pleistocene (2 million -11,000 years BP).  Accordingly, a greater diversity of birds existed in North America because they weren’t limited to those species able to survive frigid conditions.  Subsequent Ice Ages reduced the variety of birds on this continent, including most of the Psittaciformes, but Carolina parakeets were the one member of this family that did evolve the ability to live in areas with sub-freezing temperatures.  They were a Pliocene relic, along with such plant species as passion flowers and paw paw trees.  Both of these plant families have large numbers of tropical species, but only one that evolved with the capability of surviving in temperate climates.

During the Pleistocene’s warmer stages, the interstadials and full blown interglacials, Carolina parakeets must have expanded their range almost to the extent that they did during the Pliocene, but curiously I’ve found no reference to their fossils being discovered at any Pleistocene fossil site, though I know they must have lived in North America then.

References:

Audubon, John

Audubon: Writings and Drawings

Penguin 1999

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