One of ‘Darwin’s Finches’ Struggles to Survive

SCIENCE

Discussion Ideas

Why is the mangrove finch nicknamed one of “Darwin’s finches”? Read through our super-short article on Charles Darwin’s exploration of the Galapagos Islands in the 19th century for some help.
- According to our article, “Darwin collected and documented a dazzling array of species in the Galapagos. He studied these organisms when he returned home. Eventually, Darwin focused his study on his collection of finches . . . The finches were very similar, but had beaks of different sizes and shapes. Darwin theorized that the beaks were adaptations that helped each species of finch eat a different type of food . . . [This] was integral to his theory of natural selection, a part of the larger process of evolution.”

How exactly do “Darwin’s finches” contribute to the history of science? Read through the first part of our short encyclopedic entry on “speciation” for some help.
- According to our entry, “The finches are isolated from one another by the ocean. Over millions of years, each species of finch developed a unique beak specially adapted to the kinds of food it eats. Some finches have large, blunt beaks that can crack the hard shells of nuts and seeds. Other finches have long, thin beaks that can probe into cactus flowers without the bird being poked by the cactus spines. Still other finches have medium-size beaks that can catch and grasp insects. Because they are isolated, the birds don’t breed with one another and have therefore developed into unique species with unique characteristics.”
  - FYI: Mangrove finches are insectivores. According to Nat Geo News, “Their long, pointed beak curves downward, which helps them lift off tree bark scales and find hidden insects.”

Our encyclopedic entry describes five types of speciation: allopatric, peripatric, parapatric, sympatric, and artificial. Which type of speciation did Darwin describe with his theory about the Galapagos finches?
- Allopatric speciation, the situation when a single population of a species is geographically divided into separate groups. With different lifestyles (influenced by factors such as diet or habitat) and unable to mate with each other, a new species evolves.

Why are mangrove finches endangered?
An invasive species, a type of fly, “lays its eggs in mangrove finch nests. At night the rice-size larvae attack hatchlings through their ear and nasal cavities. The larvae then feast on the chick’s blood and flesh, causing the bird’s deformation and usually death.”
Illustration by Emily M. Eng, National Geographic
How are scientists rescuing the critically endangered population of mangrove finches?
- Scientists take mangrove finch eggs from the wild to raise in the safety of an incubator at a research station. More than two dozen mangrove finch chicks have been released into the wild. Take a look at a scientist dishing out some TLC (and insect mash) to a mangrove finch chick here.