Studies of Galápagos Finches
The Galápagos finches scientists have been studying how these populations of finches interact with other populations on the islands (biotic factors), and are affected by changes in the environment of the island (abiotic factors). An important part of studying populations is understanding how individuals vary from one another. To examine this, the scientists were able to place colored bands on the birds' legs so they could tell them apart. They took measurements of the important physical characteristics of each bird. They also studied the behavior of the birds, and recorded field notes for important aspects of the populations' survival: mating, foraging for food, and evading predators. To study the birds' interactions with other species, they tracked the vegetation and predators on the island.
Death and Survival in the Galápagos
Scientists were surprised to see a large drop in the population of finches during several years of their study. Beginning in 1976 and continuing through 1977, a large majority of the finches died. The scientists investigated this important change in the finch population. They asked these two questions:
- Why are so many finches dying?
- Why are some of the finches able to survive?
To investigate this, they examined possible influences of the environment on the finches, and interactions of the finches with other populations. The reasons for the death of so many finches quickly became clear. The reasons that some were able to survive were more difficult to figure out. This puzzle required putting together a lot of data, and not all of it led directly to the same conclusions.