Showing posts with label Darwin Finch. Show all posts
Showing posts with label Darwin Finch. Show all posts

Wednesday, January 9, 2019

Endangered Species - DARWIN FINCH

English: A mangrove finch, the rarest of Darwi...
A mangrove finch, the rarest of Darwin's finches.
 (Photo credit: 
Have you ever wondered about how man became the dominant species in the world? We're not the biggest, the fastest, the strongest or the hardest working creature on the planet. What separates us from other creatures is both our intelligence and our ability to use tools. Man's use of tools dates back to prehistoric ages when we used stones and clubs throughout history. Over the years we have developed new tools making our lives easier and making it possible to dominate our environment.

For many years it was thought that man was the only creature that used tools, through research, it was observed that other animals also use tools. Sticks and stones have been observed being used for various purposes. Other than humans, primates are known to make the widest use of tools and the Woodpecker Finch that collects up to 50% of their diet by using a tool to collect their food. These finches are second only to man, in their reliance of tools in order to obtain food. The Woodpecker Finch uses sticks, twigs and cactus spines to make up for its short tongue and gather insects from plants and trees.

The Woodpecker Finch is just one of 14 species known as Darwin Finch named after Charles Darwin. Darwin collected these finches during his visit to the Galapagos. Brownish Grey in color these noisy birds were unimpressive at first - Darwin thought them to be blackbirds or grosbeaks. Upon returning to England, Darwin presented the birds along with other animals he collected during his voyage to the Geological Society of London it was there that an ornithologist, discovered that Darwin had discovered an entirely new group of birds and 12 different species. It was this discovery, which directly led to his theory of evolution and the transmutation of species.

"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 archipelago, one species had been taken and modified for different ends"

Since the days of Darwin, this group of birds continues to intrigue scientists. The term "Darwin Finch" was coined in the 1900's and made popular by David Lack who spent 3 months in the Galapagos studying the birds and wrote a book about his studies. Yet the real experts on the Darwin Finch are Peter and Rosemary Grant who spent 30 years studying the birds and wrote the Pulitzer Prize winning book The Beak of the Finch. Winners of the prestigious Balzan prize for popular biology their citation reads...

"Peter and Rosemary Grant are distinguished for their remarkable long-term studies demonstrating evolution in action in Galapagos finches. They have demonstrated how very rapid changes in body and beak size in response to changes in the food supply are driven by natural selection. They have also elucidated the mechanisms by which new species arise and how genetic diversity is maintained in natural populations. The work of the Grants has had a seminal influence in the fields of population biology, evolution and ecology."

Through these studies, we have come to learn there are 14 species of Darwin Finch 13 in the Galapagos Islands plus one living at Cocos Island. These birds are members of the tanager family rather than a true finch. Each species is approximately the same size 10 - 20 cm making them difficult to tell apart. The primary difference between the finches is their beak size and shape which mutated to adapt to their diet ranging from seeds, insects, flowers, leaves and the blood of sea birds. For example, finches which eat insects will have a thin extended beak to poke into holes in the ground and extract the grubs. Finches that eat flowers and seeds have a claw like beaks can grind down their food and thus give them a selective advantage in circumstances in parts of the islands where seeds are the only real food available.

Typically the Darwin Finch are divided into (4) groups representing each genus: ground finches (Geospiza) are made up of 4 species seeding eating ground finches each with a crushing bill plus one cactus dwelling finch with a probing bill. There is the insect eating warbler finch (Certhidea) with its probing bill and the Cocos Finch (Pinaroloxias). As well as the more diversified group of tree finches (amarhynchus) consisting of the fruit eating vegetarian tree finch with its parrot like a bill, the small and large tree finch both dine on insects and have a grasping bill. The Woodpecker finch we discussed earlier with its probing bill. Found only on the Island of Cocos along the coast of Costa Rica, the Cocos finch which eats both fruits and insects and is the most plentiful bird on the island this is in direct contrast to the Mangrove Finch which can be found in two mangrove areas on the western coast of Isabela and is critically endangered.

Though these remarkable birds have adapted to life in the Galapagos Islands for thousands of years, it is the introduction of new species by a man that has devastated the Mangrove Finch. The mangrove finch closely resembles the Woodpecker Finch only these birds do not use tools. Historically the Mangrove Finch could be found in the mangrove areas on the east of Ferndandina and on the west, south and north of Isabela. However, recent surveys have determined the bird is now extinct on Fernandina and there is thought to be approximately 70 remaining on Isabela.

The plight of the Mangrove Finch is due to a blood sucking parasite known as the Philornis downsi. Accidently introduced to the Galapagos thought by imported fruits, the larvae of the fly emerge at night to feed both internally and externally on the blood and flesh of developing nestlings. The presence of this parasite is causing significant (16 - 95%) mortality rate in Darwin Finch and devastating both the Medium Tree Finch and Mangrove Finch both of which are now considered critically endangered.

The national park has made great strides in the conservation and preservation of endemic species from their tortoise rearing and breeding program for giant tortoises, the restoration of land iguanas to the eradication of goats and other introduced species on many of the islands.

However, P. downsi creates a whole new issue. When eradicating goats on Isabela, Pinta and Santiago the national park used radio collars to track the goats leading them to other goats in the heard. Yet using a radio collars to track flies is an impossibility. Whereas goats produce on average 2 - 3 kids after a 150 day gestational period. The P. downsi produces hundreds of off springs in a matter of days - the ramifications of which are staggering.

Since its introduction, the parasite has spread to 12 of the 13 islands and can be found in 64-100% of the nests. The Darwin Station is searching for a solution to this problem that affects all of the Darwin Finch as well as the other land birds in Galapagos.

In order to protect the Mangrove Finch from extinction, the national park has been working on a captive breeding program both for the finch as well as for the P. downsi. Their hopes are to breed the finch in a safe environment. While in studying the P. downsi it is in hopes to create a sterile version of the parasite which can be introduced into the population to eradicate it. Additionally, the park is working to eradicate of rats (another predator) in the habitat of the Mangrove Finch. They have established a monitoring program and through these resources and education, the park and scientists are hopeful they can save the Mangrove Finch from extinction and continue to preserve the endemic species of the Galapagos Islands.

Sunday, April 1, 2018

The Origin of Galapagos Finches

Geospiza magnirostris - Picture: Wikipedia
Charles Darwin came to the islands and collected what is now called Darwin's finches, although Darwin himself did not think to give them this name. There are 14 Darwin's finches all in all; 13 in the Galapagos Islands and 1 in the Coco's Island which is about 400 miles north of the Galapagos all of them belonging to the Passerine group.

There is evidence that evolution took place on the island particularly involving Galapagos finches. Finches that have the same ability as woodpeckers because they are able to peck on woods are found here; as well as vampire finches, which suck the blood of other birds. Genetic specialists have suggested that all 13 of Darwin's species have evolved from a flock of giving or take 30 birds arriving about a million years ago.

Darwin's finches / Galapagos finches are 10-20 centimeters in size and the most important differences among each one of them, is the shape and size of their beaks. Each shape and size of beak has evolved and adapted to different food sources. Large-beaked finches like bigger seeds or nuts, while smaller-beaked finches prefer smaller seeds. Middle-beaked finches can also be found on the island.

Apart from seeds, these finches differ in other food choices. Some eat insects, leaves, and some remove turtle ticks. The vampire finch, for instance, feeds on the blood of seabirds. The woodpecker finch, on the other hand, is one among the few birds in the world that uses various "tools" like twigs or cactus spine when feeding. They particularly use these tools to pry larvae and other insects from beneath barks of trees or cacti.

The ground finches have bills that are more adapted to crushing seeds. The Vampire Finch, which is found in Wolf Island, is a type of ground finch and its behavior likely evolved from eating insect parasites from its own plumage.

Tree finches are another type of Galapagos finches. They mainly feed on insects and differ from ground finches by the sharpness of their bill which is better suited in grasping insects. Cactus finches enjoy eating small insects in the flowers of the cactus plants.

The 13 species of finches in the Galapagos are of the genus Geospiza and are likely to have descended from a South American species, either the St.Lucia black finch or the blue-black grassquit. When Darwin was collecting these birds, he did not immediately realize that these birds were all different species of finches. Soon after he suspected that there was more than meets the eye, he began his work on "Transmutation of the Species".

There's no doubt that these species are particularly popular for their significance in the development of the theory of evolution and are popular pet choices as well.

Grace Hutchings is a World Class Finch Fanatic who loves finches. To learn more about pet finches please go to
Article Source: EzineArticles

Sunday, December 24, 2017

FINCHES From Galapagos Are Known As DARWIN`S FINCHES

Galapagos Cactus Finch / A Darwin Finch (also ...
Galapagos Cactus Finch / A Darwin Finch (also known as the Galápagos Finches or as Geospizinae) are a group of 15 species of Passerine birds, now placed in the tanager family rather than the true finch family. (Photo credit: Wikipedia)
The finches from the Galapagos Islands were part of Darwin's original research on evolution, Darwin spent a great deal of time on the islands studying the finches behavior and evolution. These finches are frequently referred to as Darwin's Finches.

On the Galapagos Islands, you will find thirteen different species of finch. There is some controversy here, as some people report the species count to be fourteen. Each of these species is a direct descendant of one original species of finch that was found on the island. The Galapagos Islands have such varying climates, and temperatures that the little birds had to adapt to the area they lived in whether it be hot or humid.

The biggest adaptation they made was in their beaks. Of the thirteen species of finches found on the islands, you will find different beak structures among them. As years went by, the little bird's beaks evolved to better enable them to eat the food sources most readily available in their habitat. As hard as we work to provide our pet birds with the perfect habitat, and climates, it should amaze us that these little creatures have survived at all. Darwin himself found these little birds to be fantastic adapters to their environment.

All the ground finches, (Small Ground Finch, Medium Ground Finch, Large Ground Finch and Sharp Beaked Ground Finch) have crushing beaks. The Vegetarian Finch also has a crushing beak. While the Tree Finch and the Cactus Finch both have beaks built more for grasping. The Woodpecker Finch and the Warbler Finch, both have beaks suited to probing for their food.

The different species of ground finches use their crushing beaks to pick ticks from tortoises and iguanas for food. They will also kick eggs into rocks and eat the contents of the egg. The Woodpecker Finch will use twigs and cactus spines like tools to dig the larva out of tree branches, one of the only species to use tools.

The Sharp Beaked Ground Finch is often referred to as a vampire. It will land on the backs of the Masked Boobies and peck them to feed on their blood. Rather a vicious little finch.

The thirteen species of finch found on the islands are not considered the brightest or the most colorful of the finch family. In fact, these finches are mostly in shades of grey, black, brown and olive-green.

These amazing little birds manage to survive some extreme and harsh conditions on the islands. Some years there is adequate rainfall and when this occurs there is more than enough food to sustain all the birds on the islands. However, this is not the case every year. Some years the islands are drought stricken and the food is scarce. This is the reason the birds have evolved and adapted to allow them to eat a greater variety of foods. They do not always have the abundance of grass seeds, and their adaptive beaks come in handy.

These compact birds blend into their surroundings very well. They are small like sparrows. The Vegetarian Finch is about the biggest finch on the islands. Their drab colors and quiet mannerisms help to hide them from natural predators.

This is a good thing. The finches from Galapagos are a real treat to see because they are endangered. There are very few of Darwin's Finches left on the islands. Evolution, I guess, can only protect them for so long.

Learn the joy of Finch companionship and how to buy, keep and raise healthy Finches. Come find all the information you need at Galapagos Finches.

    I am Ralph Siskin and I have been raising and learning about Finches for quite some time. I love these birds and want to share what I know with other Finch lovers or people just interested in birds. I invite you to come see my site and read my free mini-course on " Top 10 Secrets To Healthy & Happy Finches" by clicking to
    Article Source: EzineArticles

Wednesday, July 19, 2017

DARWIN'S FINCHES and the Creationism Evolution Debate

Evolutionists have used Darwin's finches to give evidence to give credence to their theory in the creationism evolution debate (called macro evolution). Scientific evidence does not support the idea however.

Darwin Finch Photo: Wikimedia

For those unfamiliar with Darwin's finches, these were the birds that he believed gave some evidence that evolution was possible. He discovered these birds when he travelled to the Galapagos Islands near South America.

He took weeks to study these birds and realized that the length of the beaks, tended, to increase in size when there was a famine. This was necessary, he thought, to obtain the seeds during famines(The seeds were not as easy to get to).

Because of this increase in size, Darwin counted on the fact that these types of changes would eventually lead to the finch evolving into another type of bird (or else this kind of thing was possible).

Eventually, Darwinists took this line of thinking even further and used these finches as a great illustration of how evolution occurred.
Little did Darwin or his followers realize that there were quite a number of major problems with this kind of thinking:

1. The finches still were finches. No evolution (macro evolution) ever took place.
2. The beaks of these finches eventually returned to their normal size, once the drought was over.

No evolution ever occurred.

Evolution (macro evolution) only occurs if one kind of creature changes into an entirely different creature. (If this kind of change does not occur then, of course, no evolution has occurred)changes that occur within various kinds of creatures (such as beak size) has nothing to do with evolution (these small changes are referred to as micro evolution and no one argues whether these types of changes occur or not.)

But this micro evolution has never been known to lead to macro evolution (real evolution) ever. And this is a real problem for those that believe in the theory of evolution. Whether it is finches or any other kind of creature, there has never been even one case of evolution that can be verified (macro).

The example of Darwin's finches, unfortunately is still used by teachers and professors and found in textbooks throughout the US even though it has been proved wrong decades ago.