Scientists are working to sustain a bird population found nowhere else in the world.
St. Louis Post-Dispatch
By Jeffrey Bonner, President of the Saint Louis Zoo
March 2, 2008
In the third of a monthly series this year, Saint Louis Zoo President Jeffrey Bonner explores a part of the globe where the Zoo is working to conserve threatened species, protect natural habitat and partner with other organizations to strengthen the web of life in which we all live.
The Galapagos Islands first appeared on a map of the world drawn by the famous cartographer Gerardus Mercator in the year 1570. At that time they were referred to as "Insulae de los Galopegos," or Islands of the Tortoises. Personally, I think their early common name - the Enchanted Islands - captures their magic and mystery.
Straddling the equator some 600 miles from Ecuador, they shimmer in the distance and, as you approach, they rise abruptly from the ocean - great cones of ancient and live volcanoes inundated by the sea. Stepping ashore is like stepping into another world.
Cactus-like plants twist into bizarre shapes silhouetted against the hazy blue sky. Marine iguanas, looking like miniature dinosaurs, glare with a malevolent fearlessness as you approach. They dive into the water and emerge to snort salty mist. Sea lions gaze balefully as you approach them, then with an air of indolence roll over to find a more comfortable position on the beach. In the Galapagos, you are the alien observer.
Blue-footed boobies strut in front of you and often make their nests directly on the small, carefully demarcated paths where tourists must walk. Cormorants have long since lost their ability to fly, but they swim and dive with an energy that seems boundless. Magnificent frigate birds inflate red bladders that make them appear almost double in size. Albatrosses conduct their elaborate mating dances, oblivious to the gawking intruders from another world.
The vast majority of the birds you see here are found nowhere else on our planet. The Saint Louis Zoo is working to ensure the survival of the unique birds of the Galapagos.
Paradise and People
Unlike the giant tortoises that provided fresh meat to whalers in past centuries, the birds of the Galapagos Islands were of little or no economic utility. Amazingly enough, not a single species or subspecies of birdlife has gone extinct on the islands in historic times. Compare this to the Hawaiian Islands, where about half their bird species have gone extinct since these islands were discovered. Sadly, these were what we call "endemic" species, found only on Hawaii and no place else on Earth.
Waves of human invaders landed in Hawaii starting with the Polynesians, and each wave brought with them new species of plants and animals. Domestic animals escaped and "went native," surviving on whatever they could eat. Rats came along, as did insects like mosquitoes. Both carried diseases for which the native animals and first human colonizers had no resistance.
We estimate that some 88 endemic species of birds inhabited the islands when the Polynesians arrived in the first century, and only 26 remain. In the end, Hawaii was, at least from the birds' point of view, more of a hell than a paradise.
Not so the Galapagos. Because of the chronic lack of water on the 16 main islands and six smaller islands, the islands were never settled to the extent of Hawaii. Also, the entire archipelago was protected as a national park by Ecuador in 1959 and later as a UNESCO World Heritage Site in 1978. It is due to Ecuador's foresight and commitment that this natural wonderland remains with us today.
That doesn't mean that humans didn't have a profound impact on the Galapagos Islands, a popular tourist destination. Today, some 700 species of plants have been introduced by humans. Those plants crowd out some of the natives, especially in less arid reaches. In addition, interlopers include black rats, mice, cockroaches and ants. Of the domestic animals that go wild, pigs, cats and goats can potentially cause the most damage to the environment. They can multiply rapidly if left alone. For example, in 1959, fishermen let one male and two female goats loose on Pinta Island. By 1973, the flock had reached 30,000.
None of the damage is irreversible, though. As of 2006, the Galapagos National Park had removed all goats, pigs and donkeys from the uninhabited islands, the largest such success in history.
So the Galapagos remain fairly pristine. Where a large number of Hawaii's bird species are extinct, none of the birds of the Galapagos are gone. At least for now.
When Patty Parker came to the Saint Louis Zoo in 2000 as our senior scientist and professor of zoological studies at University of Missouri-St. Louis, she worked closely with the Charles Darwin Research Station and the Galapagos National Park Service to set up a unique monitoring and research program focused on the birds of the Galapagos. Eventually, she and Eric Miller, the Zoo's senior vice president, would develop the Center for Avian Health in the Galapagos as part of the Zoo's WildCare Institute.
Sharon Deem, the Zoo's newest Galapagos Islands employee, is a veterinarian who also has a doctorate in epidemiology, the science that studies how diseases spread.
Her job is to monitor the birds of the islands for existing or, more ominously, new diseases. Many of the diseases we're worried about are those that could come in with the chickens that arrive from mainland Ecuador to feed the people who live on the island of Santa Cruz.
Of great concern was the discovery of the presence of a mosquito with a tongue-twisting name - Culex quinquefasciatus. First seen in the mid-1980s, in 2005 it was determined that this new arrival was permanently established, which could be bad news. The Culex mosquito is the vector for a form of malaria that is lethal to many bird species. Should a mosquito arrive in the islands infected with avian malaria, many others could carry the pathogen around.
What Parker and her fellow scientists from the Zoo and UMSL have found is that many pathogens are endemic to the Galapagos. Then there are parasites and pathogens that appear to have jumped from one species to another. In nature, that's normal. Most importantly, Parker has found pathogens and their insect vectors that clearly came with people. Those are the ones that could bring an epidemic of massive proportions to these relatively pristine islands.
Together, Parker and Deem are the best chance the Galapagos birds have to avoid the diseases that have swept through mainland populations. By working closely with the Galapagos National Park, which is responsible for the safeguarding of the birds, they can assess present dangers and help develop plans of action for existing threats and the arrival of any new ones.
Diseases like avian malaria, avian influenza and many others could be devastating if carried to the islands by humans. Island populations tend to be small to begin with, their population densities are often high, and their resistance to pathogens is often low because of their isolation. Add to that the fact that with no place to escape, you have the recipe for potential disaster.
With fewer than 100 mangrove finches, fewer than 140 Floriana mockingbirds and fewer than 2,000 Galapagos penguins, some bird species are hanging by a thread. But to date, we have avoided the catastrophic extinctions that ravaged Hawaii. The birds of the Galapagos, among the most amazing on our planet, are safe for now. It is hoped they will remain that way - untroubled in paradise.
Republished with the permission of the St. Louis Post-Dispatch
Copyright 2008 St. Louis Post-Dispatch
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