By Elizabeth Deatrick
BU News Service
Ducking my head to avoid a shower of raindrops from overgrown foliage, I push open the heavy metal doors of the Andean condor cage at the Franklin Park Zoo. If it wasn’t so cold, the scene could have come straight out of Jurassic Park: the cage is enormous, a domed web dark against the sky. Vines stretch like cobwebs over its roof. The visitor walkway, a tube of heavy, black wire mesh with a wooden floor, stands about fifteen feet off the ground, and runs between full-grown trees and an artificial waterfall, long-since dried up.
On the damp cement and stone of the old cascade, stoops an enormous female condor: Inti, a jet-black bird who clasps her crag with dignity. Her bald head is drawn back into the white ruff of her neck. Her mate, Humphrey, hops up the cliff face to join her; as he draws close, she snaps at him.
Inti’s brief testiness does not bode well for her species. It’s rare to see a wild Andean condor these days, even in the highest mountains of Peru and Argentina. Only around 2,000 of these magnificent creatures remain in the wild, though as with many other endangered species, zoos across the U.S. are working to maintain them in captivity, with as much genetic variety as possible. Humphrey’s pairing with Inti is a result of that program; he’s been procured from the Sedgewick Zoo, in Kansas, as a replacement for an older bird, named Tito. Tito was once the most genetically valuable Andean condor in captivity, and the keepers had high hopes for him.
Despite forming a strong bond with Inti, Tito never managed to fertilize her eggs. Year after year, Inti climbed inside the wooden nest box built into the side of the main cage, scraped out a sandy, bowl-shaped nest, and tenderly brooded a completely useless infertile egg. Even artificial insemination didn’t work: by the time the zoo tried it, Tito had aged out of his prime, and his sperm count was too low.
At six years old, Humphrey has only just entered sexual maturity. His flight feathers are still the dusky grey of a juvenile; they’ll fade to the bright white feathers of the adult male within the next year. At feeding time, Humphrey hops back and forth, waiting for another sliver of horsemeat to be shoved through the mesh. “You can see his head flush red when he gets excited,” notes Greg Stimpson, Lead Keeper of Birds for Franklin Park, as we shiver and watch the birds. I ask if Humphrey’s personality could push Inti away. Stimpson shrugs. He ruefully notes that it takes a long time for condors to form relationships (technically known as pair-bonds). “They’re South American birds, so they mate during our winter, and we got Humphrey too late. We missed this year’s mating cycle.”
Figuring out condor reproduction is a fairly urgent matter: according to a 2007 study, all wild condors are closely related to each other––which means that zookeepers much watch out for inbreeding. The Association of Zoos and Aquariums keeps tabs on where all the individuals of a given species are, how many offspring they’ve had, and how rare their genes are. This collection of records is called a studbook. Wild-caught animals have a high value in the studbook, since they might carry some genes that the captive population doesn’t. Meanwhile, animals with many siblings, whose ancestors have been in captivity for generations, are assigned a lower value.
The studbook may sound almost callously clinical, but several conservation success stories have proved its value. Not only does it help avoid inbreeding, but if Andean condors ever go extinct in the wild (as their cousins, the California condors, did) keeping the genetic variation of the captive population high could ease their reintroduction to the wild. If zoos are careful, the genes of captive birds will mirror those of their wild relatives. From a genetic perspective, it would be as if the wild birds never went extinct.
Luckily, Inti and Humphrey’s wild relatives are relatively safe for now. They’ve adapted to humans’ influence on their environment surprisingly well, supplementing their diet of native guanacos and rheas with goats, sheep, rabbits, and non-native deer. They’re hardy birds, capable of handling the pesticides and other toxins that we release into their environment. Case in point: few other birds could live comfortably in the cage at Franklin Park. Since 1913, when the cage was built, lead-based paint has dripped off the bars and into the soil and pools of water below. The heavy metals killed the waterbirds and macaws that once lived there, but because the old pools have been filled in and the condors don’t spend much time on the ground, they’re hardly affected by the lead contamination.
As I watch Inti and Humphrey through the wire mesh, and the theme from Chariots of Fire echoes and swells from the nearby Franklin Park racetrack, Humphrey arches his neck like a horse on parade and turns to face his mate. His wings partially unfurl, farther than my own arms can reach. His head and comb flush a deep red. His chest contracts, and he lets out a soft, hiccuping, drumming rhythm. Inti reaches out, and gently nibbles at his beak. Eventually they fall back into statuesque silence, huddled against the rain––but beside each other now, staring back at me, together.