The Cozumel thrasher (''Toxostoma guttatum'') is a

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

from the mockingbird

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

( Mimidae), which is

endemic Endemism is the state of a species being found 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 found elsew ...

to the island of

Cozumel Cozumel (; yua, Kùutsmil) is an island and municipality in the Caribbean Sea off the eastern coast of Mexico's Yucatán Peninsula, opposite Playa del Carmen. It is separated from the mainland by the Cozumel Channel and is close to the Yucatán ...

off the

Yucatán Peninsula The Yucatán Peninsula (, also , ; es, Península de Yucatán ) is a large peninsula in southeastern Mexico and adjacent portions of Belize and Guatemala. The peninsula extends towards the northeast, separating the Gulf of Mexico to the north ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. It is believed to be the most critically endangered species of bird in Mexico - if it indeed still exists, which is probable but not certain.ENS (2004) This bird is closely related to the long-billed and brown thrasher. It has been generally described as shy, but there have been descriptions to the contrary. It was once abundant throughout Cozumel before two hurricanes greatly affected its numbers.

Invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

are also thought to have impacted the population of the thrasher.

Taxonomy

The Cozumel thrasher was first described as ''Harporhynchus guttatus'' by

Robert Ridgway Robert Ridgway (July 2, 1850 – March 25, 1929) was an American ornithologist specializing in systematics. He was appointed in 1880 by Spencer Fullerton Baird, secretary of the Smithsonian Institution, to be the first full-time curator of bird ...

in 1885. It has been described as a subspecies to its relative the

long-billed thrasher The long-billed thrasher (''Toxostoma longirostre'') is a medium-sized resident songbird of South Texas and eastern Mexico. It bears a strong resemblance to its close relative the brown thrasher in appearance, calls, and various other behavio ...

, but was considered a separate species when it was determined in a 1998 study that it differed genetically more than five percent from both the long-billed and

brown thrasher The brown thrasher (''Toxostoma rufum''), sometimes erroneously called the brown thrush or fox-coloured thrush, is a bird in the family Mimidae, which also includes the New World catbirds and mockingbirds. The brown thrasher is abundant through ...

. In the same study it was determined to be the basal member of the ''rufum'' group of ''Toxostoma'' thrashers. The bird is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

Description

The thrasher is 21.5 to 24 cm in length. The adult has a brown

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

, back, shoulders, and

rump Rump may refer to: * Rump (animal) ** Buttocks * Rump steak, slightly different cuts of meat in Britain and America * Rump kernel, software run in userspace that offers kernel functionality in NetBSD Politics *Rump cabinet * Rump legislature * Ru ...

that becomes more red in its tint on its lower back and rump. Greater and lesser coverts are a warm brown with concealed white tips, preceded with a black bar.

Primaries Primary elections, or direct primary are a voting process by which voters can indicate their preference for their party's candidate, or a candidate in general, in an upcoming general election, local election, or by-election. Depending on the c ...

and secondaries are grayish-brown with warm rufous-brown outer webs. The

rectrices Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...

are also have a warm brown color. The lores and ear-coverts are a mottled grey brown. The chin and throat are an off-white color with a blackish partial malar stripe. The chest is a buffy-white in color with stark black teardrop shaped spots. The belly is off-white, and the flanks have larger black spots. Its

vent Vent or vents may refer to: Science and technology Biology *Vent, the cloaca region of an animal * Vent DNA polymerase, a thermostable DNA polymerase Geology *Hydrothermal vent, a fissure in a planet's surface from which geothermally heated wate ...

is buffy and an underwing that is buffy-white with darker markings. The

iris Iris most often refers to: *Iris (anatomy), part of the eye *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (color), an ambiguous color term Iris or IRIS may also refer to: Arts and media Fictional ent ...

is yellow, the

bill Bill(s) may refer to: Common meanings * Banknote, paper cash (especially in the United States) * Bill (law), a proposed law put before a legislature * Invoice, commercial document issued by a seller to a buyer * Bill, a bird or animal's beak Plac ...

is grayish-brown, and the legs are brown with a dull tint. Juveniles'

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

have not been recorded, but presumably is similar in development to adulthood like the long-billed and brown thrasher.

Similar species

The Cozumel thrasher is similar in appearance to the long-billed thrasher (26.5–29 cm in length), but is smaller, darker in color, has a blacker bill, and the markings are more sharply defined. No other thrasher species coexist on the island, but is most likely to be confused with the migratory wood thrush. The wood thrush differs in lacking wing bars, a shorter beak, and a different shape.

Distribution and habitat

The distribution of the thrasher is restricted to Isla Cozumel which is 45 km long and 20 km wide. The habitat preferences for the thrasher is thought to be in low and medium deciduous and semi-deciduous forests. It may have once been most abundant in forest edges adjacent to clearings.

Behavior and ecology

The thrasher is predominately terrestrial and elusive and as with all members of the genus ''Toxostoma'', it may resort to running instead of flying when startled. Ornithologists

Ludlow Griscom Ludlow Griscom (June 17, 1890 – May 28, 1959) was an American ornithologist known as a pioneer in field ornithology. His emphasis on the identification of free-flying birds by field marks became widely adopted by professionals and amateurs. ...

and Raymond A. Paynter, Jr. had noted its secretive behavior, but

James Bond The ''James Bond'' series focuses on a fictional British Secret Service agent created in 1953 by writer Ian Fleming, who featured him in twelve novels and two short-story collections. Since Fleming's death in 1964, eight other authors have ...

did not. The song is described as a rich varied warbling, slightly scratchy with little repetition. Bond described its alarm note being similar to the brown thrasher.

Status

The numbers of this bird declined rapidly when

Hurricane Gilbert Hurricane Gilbert was the second most intense tropical cyclone on record in the Atlantic basin in terms of barometric pressure, only behind Hurricane Wilma in 2005. An extremely powerful tropical cyclone that formed during the 1988 Atlantic hurr ...

hit this island on September 14, 1988. Until it was sighted in June 2004, this bird had last been seen in 1995, the same year that Hurricane Roxanne hit Cozumel on October 11, and it was widely believed to have become

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

. It is still unclear what damage the impact of Hurricanes Emily and Wilma in 2005 caused; it seems that the bird was not found anymore during a survey in December 2006. Inquiry from the local population had suggested that the species would likely be encountered near the

Mayan Mayan most commonly refers to: * Maya peoples, various indigenous peoples of Mesoamerica and northern Central America * Maya civilization, pre-Columbian culture of Mesoamerica and northern Central America * Mayan languages, language family spoken ...

ruins of San Gervasio. The last - unconfirmed - sightings were in April 2006, where an apparent ''T. guttatum'' was sighted at the Cozumel Golf Club; in October and December 2007, thrashers were also seen but could not be reliably identified as ''T. guttatum''. Relocation efforts continue; though at least a few birds seem to survive, the continuing existence of this species had not been verified as of January 2008.Curry (2008) Some scientists believe that other factors must have contributed to the bird's decline, because the Cozumel thrasher likely survived hurricanes for millennia.

Introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

, including predatory

boa constrictor The boa constrictor (scientific name also ''Boa constrictor''), also called the red-tailed boa, is a species of large, non-venomous, heavy-bodied snake that is frequently kept and bred in captivity. The boa constrictor is a member of the family B ...

s—which were released on the island in 1971 and are now abundant—may also have had a detrimental effect.

Footnotes

References

* Curry, Robert L. (2007)
''El cuitlacoche de cozumel'' - The endemic thrasher of Cozumel Island
Version of 2008-JAN-28. Retrieved 2008-FEB-12. *Environment News Service (2004)
The Cozumel Thrasher: One Bird Away From Extinction
Includes habitat photo. Version of 2004-JUL-09. Retrieved 2007-FEB-08. *Surfbird News (2006)

Version of 2006-DEC-28. Retrieved 2008-FEB-12.

External links

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

Cozumel Thrasher Species Factsheet
Retrieved 2007-FEB-08. {{Taxonbar, from=Q1585778

Cozumel thrasher The Cozumel thrasher (''Toxostoma guttatum'') is a bird from the mockingbird family ( Mimidae), which is endemic to the island of Cozumel off the Yucatán Peninsula, Mexico. It is believed to be the most critically endangered species of bird in M ...

Birds of the Yucatán Peninsula Endemic birds of Southern Mexico Endemic fauna of Cozumel Critically endangered biota of Mexico

Taxa named by Robert Ridgway