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Monday, January 24, 2011

Galapagos Islands: Port Boauerizo & Darwin’s Finches

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PORT BAQUERIZO ON SAN CRISTOBAL ISLAND

This morning’s excursion put us on the island of San Cristobal at Port Boquerizo. We landed in a tiny port with a small village. The walk today was a paved boardwalk which was much easier to hike on than the rocky volcanic outcrops we had yesterday.

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Well it was easier until it started sloping uphill… hiking I can do, hiking in a million degree heat with a 22 pound lens makes things just a tiny bit difficult. But the views, the views were spectacular.

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THE PATH WE HIKED WITH OUR BOAT OFF IN THE DISTANCE

We made it to the Galapagos in the tail end of the dry season and man was this island toasted. Most of the trees and vegetation had long shed their leaves and everything seemed to be ready for the rain to fall. Everything seemed dead until you looked closer. The finches in particular were having a grand time chirping and flitting from tree to tree.

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LOVE THE EARLY MORNING LIGHT IN THIS SHOT OF A FINCH GATHERING SUPPLIES FOR HIS NEST

I spotted a finch nest nestled in a cactus later that day, sadly no one was home but it was a cool find anyways. I don’t know how a bird goes about making a nest in a cactus but it sounds like a good idea to me. Have you touched a cactus… yea I have quite a bit while hiking and it isn’t pretty. Talk about a great deterrent to intruders.

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FINCH NEST

I was excited at seeing so many of the famous Darwin finches. Charles Darwin, on The Voyage of the Beagle which took five years, arrived in the islands in 1831 where he observed and developed his curiosity about how life came to be and evolved on the islands. It was based off his research on the islands of the finches that he eventually wrote his theory of evolution, a book On the Origin of Species written in 1859. While on the boat, in his diary, he wrote:

“Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this one archipelago, one species had been taken and modified for different ends.”

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THESE ARE SOME FAMOUS BIRDS

It takes a CONSIDERABLE amount of effort and time to try and identify Darwin finches. It is so difficult because the variability of their beaks and their size, which you are supposed to use to identify them, are exacerbated by interbreeding and range overlap. For instance a medium ground finch and a large ground finch can look virtually the same. Michael Harris, the author of a Galapagos bird guidebook cautioned that

“It is only a very wise man or a fool who thinks that he is able to identify all the finches which he sees.”

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WHAT I BELIEVE TO BE THE LARGE CACTUS FINCH

Therefore I will label the finches as I believe they are but please don’t take my word that they are all correct… I will leave that pleasure to more experienced birders or naturalists to decipher… I can admit that it is beyond me to make an accurate name for each.

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WHAT I BELIEVE TO BE THE LARGE GROUND FINCH USING HIS OVER-SIZED BILL TO CRACK SEEDS

It is so difficult to identify finches because of precisely what makes the Darwin finches so intriguing… evolution. If we believe these finches have a common ancestor than if we trace them back in time they should become closer and closer in form.

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WHAT I BELIEVE TO BE THE CACTUS FINCH

At the branch point they become different aka specialized but with the Darwin finches they are still in the process of completely separating, the species of each are not so different that they have gotten a fertility barrier hence there is a certain amount of hybridization still occurring. In essence they are still evolving.

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WHAT I BELIEVE TO BE THE SMALL GROUND FINCH

At one point the populations, from what we know of evolution, have a few options. Either they do not become too different and continue to hybridize where they slowly remerge into the same species, OR the two populations compete with one species eventually becoming extinct, OR the two populations avoid competition forcing specialized skills where they would continue to diverge until the gene pools were so separate they could no longer hybridize.

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WHAT I BELIEVE TO BE THE SHARP BEAKED GROUND FINCH

Darwin’s finches are still being studied today with the hope that new discoveries will have other evolutionary tales to tell.

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WHAT I BELIEVE TO BE THE MEDIUM GROUND FINCH

4 comments:

Alissa Nicolau said...

Wonderful, wonderful photos. A trip of a lifetime! Perfect you got to experience such a place together and enjoy photographing everything in sight together!

paul peggy zeus said...

Crisp, clear photos. nice job on your research.

lilmansworld said...

wing

Totoro and Duckie said...

Awesome photos and information!!! :)

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