The Española cactus finch (''Geospiza conirostris''), is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

in the

tanager The tanagers (singular ) comprise the bird family (biology), family Thraupidae, in the order Passeriformes. The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12 ...

family

Thraupidae The tanagers (singular ) comprise the bird family (biology), family Thraupidae, in the order Passeriformes. The family has a Neotropical distribution and is the second-largest family of birds. It represents about 4% of all avian species and 12 ...

. It is one of

Darwin's finches Darwin's finches (also known as the Galápagos finches) are a group of about 18 species of passerine birds. They are well known for being a classic example of adaptive radiation and for their remarkable diversity in beak form and function. They ...

, and is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the Galápagos islands, where it is restricted to Española, Genovesa, and the Darwin and Wolf Islands. This rather dark bird resembles the smaller and finer-beaked common cactus finch, but the two species do not co-inhabit any island. Its natural

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

is dry

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

and it is commonly seen on the ground. Its main food source is the cactus ''

Opuntia ''Opuntia'', commonly called the prickly pear cactus, is a genus of flowering plants in the cactus family Cactaceae, many known for their flavorful fruit and showy flowers. Cacti are native to the Americas, and are well adapted to arid clima ...

''.

Taxonomy

The Española cactus finch is one of

, a group of closely related birds that

evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

on the Galápagos Islands. The group is related to the '' Tiaris'' grassquits, which are found in South America and the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

. An ancestral relative of those grassquits arrived on the Galápagos Islands some 2–3 million years ago, and the Española cactus finch is one of the species that evolved from that ancestor.Grant & Grant (2008), p. 25. From a study done in 2015, the Española cactus finch (''G. conirostris'') of Española was found to be a sister to the large ground finch, not to the Genovesa cactus finch. The

International Ornithologists' Union The International Ornithologists' Union (IOU) is an international organization for the promotion of ornithology Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", ...

has changed the taxonomy based on the study. Other taxonomic authorities have kept the large cactus finch and the Genovesa cactus finch

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

Genetic speciation

The Española cactus finch (G. conirostris) first arrived in Daphne Major in 1981, when it was observed to be a newcomer by Peter and Rosemary Grant. This has enabled scientists to trace changes in its genome: it originally interbred with local finches ('' G. fortis'') but has ceased to do so in later generations. The new descendants have become a distinct species. It is the first example of

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

to be directly observed by scientists in the field. Subsequent genetic research suggests that genes for beak shape (ALX1) and beak size (HMGA2) may be crucial in separating the hybridized species from local finches. Genes relating to the finches' song may also be involved.

Description

The Española cactus finch is among the largest of the Darwin's finches, measuring in length. The male is black, with white-tipped undertail coverts. Female and immature birds range in color from dull gray to matte black, and frequently show white edges to the feathers of their underparts. File:Geospiza conirostris -Espanola, Galapagos, Ecuador-29Sept2010.jpg, Female on Española File:Geospiza conirostris -Espanola Island, Galapagos Islands, Ecuador-8.jpg, Male on Española

References

Cited works

* *

External links

Princeton Study Finds That New Species Can Develop in as Little as 2 Generations
On: SciTechDaily. November 24, 2017 {{Taxonbar, from=Q843364 Española cactus finch Endemic birds of the Galápagos Islands Española cactus finch Taxa named by Robert Ridgway Taxonomy articles created by Polbot