Tracy Aviary in the Galapagos

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Hola! I’m Ashley, and I work as the Primary Aviculturist of the South American Pavilion building here at Tracy Aviary. I love working with our South American birds, and this February I had the incredible opportunity of traveling to the actual South American continent to help with a field conservation project in the Galápagos Islands. 

The Galápagos Islands are an isolated group of islands over 800 miles off the coast of Ecuador. The separation of the islands from anywhere else has allowed something called "speciation" to run rampant. The results of this is a huge diversity of unusual plants and animals very different from their original ancestors. Because of this, there are many species endemics to the Galápagos, meaning they are native to and only found on these islands. This includes huge, tree-like prickly pear cactuses, the supremely strange flightless cormorant, and the world’s only sea-faring lizard, the marine iguana. Some of the most famous of the islands’ endemic species are the so-called Darwin’s finches. They are named this because Charles Darwin traveled to the Galápagos Islands in1835. While there, he collected various Galápagos finch specimens, which later played an important role in his formulation of the theory of evolution via natural selection. 

The natural history and human history of the Galápagos Islands has been molded by their isolation. The islands are breathtakingly beautiful, but they can also be forbidding. Sharp black rocks poke out at every angle, practically promising a twisted ankle. Almost every plant has either large spines or thorns, and all the while, the sun beats down intensly. Relative to the rest of the world, people have not been residents on these islands for long. Because of this, science has both an exciting opportunity and a daunting responsibility. We are only just beginning to learn about the effects of human habitation and travel on the plants and animals of these islands. We now have the opportunity to figure out how to preserve the natural beauty of the Galápagos and find a way for the human and non-human residents of the islands to co-exist.  

 

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Kiyoko Gotanda, with the Depatment of Zoology at Cambridge University has been studying the effects of urbanization and invasive predators on Darwin’s finches for years. This field season, I decided to go along to help with her latest project.  As the islands grow in population, people have now brought their own food to the islands. Probably much to their delight, the finches find human food, like crackers and cookies, to be quite tasty. However, this human “junk” food is likely bad for the health of the finches (as it is for other types of birds). This change in food source has unknown effects on their health and immune systems. Parasites of the Darwin’s finches have also become a pressing issue since the accidental introduction of a parasitic fly to the islands. This fly, Philornis downsi, lays it's eggs in the bird's nests, and the developing fly larvae feed on the baby birds. This can weaken or even kill the chicks. One defense the finches have against such parasites is preen oil. Preening is when a bird cleans and arranges it's feathers with it's bill. When doing this, many birds secrete preen oil over their feathers. This oil can help parasites stay away and improve the waterproofing of the feathers. Unfortunatly, very little research has been done on preen oil and what exactly it does. The goal of this project is to analyze the chemical composition of preen oil of Darwin’s finches. We then hope to see how differences in preen oil are related to urbanization and diet changes.  The differences in preen oil may be important to the finches’ self-defense against parasites.  This information can then be helpful in making decisions regarding sustainable development in the Galápagos.

 

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In order to study the preen oil of the Darwin’s finches, we first needed to obtain preen oil samples! We did this by setting up large nets to catch the birds. Once caught, we took measurements on the birds and coaxed a small preen oil sample from the preen gland of the bird. This means getting up very early (4:30am!) to set up the nets before dawn. The reason for this is because the birds are most active and most likely to be caught around dawn. It’s much safer to catch and handle birds during the cool early hours. Once the nets were set up, we waited for the birds to accidentally fly into them. We then carefully extracted the birds and measured their mass and bill length, width, and depth and the length of their wings and legs. We would also fit the birds with a small metal band that has a unique number to mark it's individual identity. The mornings were humid and buggy, but it was a lot of fun to see all the birds and their individual differences. 

We had the chance to go out mistnetting and preen oil sampling at multiple different sites. Some areas have been urbanized so the finches snack on people food. Some areas have only natural food that is available. My favorite site during my stay was a beautiful remote beach. In addition to watching the finches, I could see whimbrels and sanderlings forage along the beach while brown noddies harass brown pelicans for fish. 

 

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The Galápagos Islands are a truly unique and awe-inspiring place. So many of the animals there can be seen nowhere else on earth.  I also got to see sea lions lounge on benches on the pier, brown pelicans beg for fish from the vendors at the local fish market, and marine iguanas lounge in the middle of sidewalks. I swam alongside sea turtles, and Galápagos flycatchers routinely tried to pluck my hair for their nests. The animals there have a sort of friendliness to them. They seem to know the islands are theirs first and foremost and that all we humans are just incredibly fortunate visitors. I truly hope it stays this way. I am proud I was able to help in a conservation project in such a magical place and grateful to Tracy Aviary for helping me to do this. 

- Ashley Saulsberry: Primary Aviculturist, Tracy Aviary