One of ‘Darwin’s Finches’ Struggles to Survive

SCIENCE

One of the world’s rarest birds, the mangrove finch has dwindled to a habitat the size of just 12 city blocks. Here’s how scientists are trying to bring it back from near-extinction. (Nat Geo News)

Use our resources to understand why these little birds have such big reputations.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit, including a link to today’s MapMaker Interactive map, which maps the short, sharp decline and assisted resiliency of the mangrove finch.

mangrovefinchmap

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.”

 

The birds Darwin collected in the Galapagos inspired him and later scientists to develop the evolutionary principle of natural selection—the idea that animals evolve particular traits to suit their lifestyles. Illustration courtesy National Geographic

The birds Darwin collected in the Galapagos inspired him and later scientists to develop the evolutionary principle of natural selection—the idea that animals evolve particular traits to suit their lifestyles.
Illustration courtesy National Geographic

  • 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.”

 

  • 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

    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.

 

TEACHERS’ TOOLKIT

Nat Geo: A Darwin Finch, Crucial to Idea of Evolution, Fights for Survival

Nat Geo: The Dwindling Habitat of the Mangrove Finch map

Nat Geo: What is speciation?

Nat Geo: 1835: Darwin Explores Galapagos Islands

(extra credit!) The Royal Society: Philosophical Transactions B: How to save the rarest Darwin’s finch from extinction: the mangrove finch on Isabela Island

4 responses to “One of ‘Darwin’s Finches’ Struggles to Survive

  1. Pingback: 11 Things We Learned This Week | Nat Geo Education Blog·

  2. Pingback: 11 Things We Learned This Week | Nat Geo Education Blog·

  3. Pingback: This Week in Geographic History, February 6 – 12 | Nat Geo Education Blog·

  4. Pingback: This Week in Geographic History, September 12-18 | Nat Geo Education Blog·

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s