Zoos Couldn’t Save The Passenger Pigeon

There are lots of interesting lessons (most of them cautionary) in the extinction of the passenger pigeon 100 years ago, and most of them are raised in Carl Zimmer’s excellent story about why it happened and what scientists are doing to try and bring the species back (did you know social media played a role in wiping the passenger pigeon out?).

But here’s a point that really caught my attention:

Soon this technology-driven slaughter was decimating the passenger pigeon. Its decline was so worrisome that Congress passed the Lacey Act, one of the first laws to protect wildlife in the United States. The Lacey Act would eventually help protect many species, but for the passenger pigeon it came too late.

In 1900, the year in which the act was made into law, naturalists spotted a single wild passenger pigeon in Ohio. They never saw another one in the wild again.

For the next 14 years, the species clung to existence in a few zoos. But the birds proved to be poor breeders in captivity. Martha, the last of her kind, was barren.

That history should be kept in mind the next time you hear a zoo or marine park justify captivity and their business model by saying they are helping preserve species that might be threatened or endangered in the wild. Some species will presumably be easier to breed in captivity than passenger pigeons. Some presumably less. That will affect how long a species can “cling” to existence. But the point is that zoos and captivity are not a way to save or preserve a species. That work has to take place in the wild.

And that is completely apart from the question of whether a species can be considered “preserved” or in “existence” if it only exists in a zoo. The difference between a wild passenger pigeon and “Martha” is like the difference between a facsimile and the real, dynamic, thing. Here is how Zimmer describes Martha’s life in the Cincinnati Zoo:

People coming to the zoo to see the last passenger pigeon were disappointed by the bird, which barely budged off its perch. As Joel Greenberg writes in his recent book A Feathered River Across the Sky, some threw sand into its cage to try to force it to walk around. But on that first day of September a century ago, Martha no longer had to put up with such humiliations.

It was a quiet end to a noisy species. As recently as the mid-1800s, deafening flocks of billions of passenger pigeons swarmed across the eastern half of the United States. But they proved no match for humans, whose rapidly advancing technology drove the birds to extinction in a matter of decades.

Martha (and the story of her species), it seems, is well worth remembering.