Sierra Madre Sparrow
Encyclopedia
The Sierra Madre Sparrow (Xenospiza baileyi), also known as Bailey's Sparrow, is an endangered, range-restricted, enigmatic American sparrow
. It is endemic to Mexico
and is threatened with extinction through habitat
loss.
xénos
(ξένος), "a stranger", + spíza (σπίζα), "finch". baileyi, dedicated to Alfred M. Bailey
, who collected the 1931 specimen for Outram Bangs
.
, Jalisco
, in 1889. The eight specimens shot then were not recognized as what they were, but believed to be aberrant Savannah
or Mexican Plateau Song Sparrow
s, or hybrids. Only when another bird was taken near the city of Durango
in 1931 was it recognized as a valid and distinct species
.
The southern population was discovered only in 1945, but has been observed since then in several areas around Distrito Federal, Morelos
, and Estado de México. Between 1951, when 5 were taken near El Salto, and 2004, when a small population was rediscovered in the same area, the northern population from Jalisco and Durango
states was not found and believed to have disappeared. Meanwhile, the proposed subspecies
X. b. sierrae for the southern population was recognized to be based on individual variation and hence invalid; nonetheless, there is no gene flow
between the populations and they constitute two separate ESUs
.
It is the sole species in the genus
Xenospiza; the genus is closely related to Ammodramus
(and included in it by some authors), differing mainly in the longer, less pointed tail, and restriction to high altitude alpine grassland habitats.
, Mexico
. It is restricted to bunchgrass and marshland habitat in volcanic mountain ranges, at altitudes of 2,300-3,050 m; the lower part of the range is occupied by the northern, and the higher part by the southern population.
Habitat information for the northern population is scant, with pine
, oak
, and Arbutus
(probably Arizona Madrone, A. arizonica
) trees being mentioned. Better details are available for the more extensively studied southern population. The dominant bunchgrass species are Festuca amplissima, Peruvian feather grass
(Stipa ichu), a muhly grass (Muhlenbergia affinis), and Muhlenbergia macroura. Small woods of Montezuma Pine (Pinus montezumae
) and (probably) Lumholtz' Pine (P. lumholtzii
) occur on elevated terrain.
s. Its conservation status according to the IUCN is EN B1ab(i,ii,iii,v). This basically means that the species occurs on less than 5000 km², and that its range, available habitat, and population size are shrinking (BirdLife International 2004). Nonwithstanding the rediscovery of the northern population, no more than a handful of individuals are known to remain, and further research to locate additional subpopulations is urgently needed. In any case, the species will probably be uplisted to Critically Endangered
soon; of the 4 subpopulations known, only one (near La Cima) seems reasonably numerous.
American sparrow
American sparrows are a group of mainly New World passerine birds, forming part of the family Emberizidae. American sparrows are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns....
. It is endemic to Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
and is threatened with extinction through habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
loss.
Etymology
Xenospiza, from Ancient GreekAncient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
xénos
Xenos (Greek)
Xenos is a word used in the Greek language from Homer onwards that has a wide gradient of meaning, signifying such divergent concepts as “enemy stranger” as well as “ritual friend”.- Meanings :...
(ξένος), "a stranger", + spíza (σπίζα), "finch". baileyi, dedicated to Alfred M. Bailey
Alfred Marshall Bailey
Alfred Marshall Bailey was an American ornithologist who was associated with the Denver Museum of Natural History in Colorado for most of his working life.-Early years:...
, who collected the 1931 specimen for Outram Bangs
Outram Bangs
Outram Bangs was an American zoologist.Bangs was born in Watertown, Massachusetts and studied at Harvard from 1880 to 1884...
.
History and taxonomy
The Sierra Madre Sparrow was first discovered by scientists in the Sierra de Bolaños near BolañosBolaños
The municipality of Bolaños is located in the north of the Mexican state of Jalisco.The municipality shares its border on the north with the municipalities of Mezquitic and Villa Guerrero and to the southeast with the municipality of Chimaltitán...
, Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...
, in 1889. The eight specimens shot then were not recognized as what they were, but believed to be aberrant Savannah
Savannah Sparrow
The Savannah Sparrow is a small American sparrow. It is the only widely accepted member of the genus Passerculus...
or Mexican Plateau Song Sparrow
Song Sparrow
The Song Sparrow is a medium-sized American sparrow.Adults have brown upperparts with dark streaks on the back and are white underneath with dark streaking and a dark brown spot in the middle of the breast. They have a brown cap and a long brown rounded tail. Their face is grey with a streak...
s, or hybrids. Only when another bird was taken near the city of Durango
Durango, Durango
-Climate:The city of Durango has a semi-arid climate, classified as Bsk in the Koppen system. The climate is temperate in the western portion , with the average annual temperature being 15 °C and consisting of an average annual rainfall of 1,600 millimeters. In the eastern region, the average...
in 1931 was it recognized as a valid and distinct species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
.
The southern population was discovered only in 1945, but has been observed since then in several areas around Distrito Federal, Morelos
Morelos
Morelos officially Estado Libre y Soberano de Morelos is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 33 municipalities and its capital city is Cuernavaca....
, and Estado de México. Between 1951, when 5 were taken near El Salto, and 2004, when a small population was rediscovered in the same area, the northern population from Jalisco and Durango
Durango
Durango officially Estado Libre y Soberano de Durango is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. The state is located in Northwest Mexico. With a population of 1,632,934, it has Mexico's second-lowest population density, after Baja...
states was not found and believed to have disappeared. Meanwhile, the proposed subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
X. b. sierrae for the southern population was recognized to be based on individual variation and hence invalid; nonetheless, there is no gene flow
Gene flow
In population genetics, gene flow is the transfer of alleles of genes from one population to another.Migration into or out of a population may be responsible for a marked change in allele frequencies...
between the populations and they constitute two separate ESUs
Evolutionary Significant Unit
An Evolutionarily Significant Unit is a population of organisms that is considered distinct for purposes of conservation. Delineating ESUs is important when considering conservation action.This term can apply to any species, subspecies, geographic race, or population...
.
It is the sole species in the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Xenospiza; the genus is closely related to Ammodramus
Ammodramus
The genus Ammodramus is a group of American sparrows in the family Emberizidae. Ammodramus is Latin for "Sand Runner." Typical of these thick grass and ground loving sparrows....
(and included in it by some authors), differing mainly in the longer, less pointed tail, and restriction to high altitude alpine grassland habitats.
Distribution and habitat
The species is endemic to some mountain ranges in and near the Sierra Madre OccidentalSierra Madre Occidental
The Sierra Madre Occidental is a mountain range in western Mexico.-Setting:The range runs north to south, from just south of the Sonora–Arizona border southeast through eastern Sonora, western Chihuahua, Sinaloa, Durango, Zacatecas, Nayarit, Jalisco, Aguascalientes to Guanajuato, where it joins...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. It is restricted to bunchgrass and marshland habitat in volcanic mountain ranges, at altitudes of 2,300-3,050 m; the lower part of the range is occupied by the northern, and the higher part by the southern population.
Habitat information for the northern population is scant, with pine
Pine
Pines are trees in the genus Pinus ,in the family Pinaceae. They make up the monotypic subfamily Pinoideae. There are about 115 species of pine, although different authorities accept between 105 and 125 species.-Etymology:...
, oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
, and Arbutus
Arbutus
Arbutus is a genus of at least 14 species of flowering plants in the family Ericaceae, native to warm temperate regions of the Mediterranean, western Europe, and North America.-Description:...
(probably Arizona Madrone, A. arizonica
Arbutus arizonica
Arbutus arizonica is a tree species of southwestern North America, mostly in Mexico but also the United States, from the Sierra Madre Occidental cordillera, in the Ericaceae family...
) trees being mentioned. Better details are available for the more extensively studied southern population. The dominant bunchgrass species are Festuca amplissima, Peruvian feather grass
Peruvian feather grass
Jarava ichu, commonly known as Peruvian feather grass ichu, paja brava, and paja ichu, is a grass endemic to Guatemala, Mexico, Costa Rica, El Salvador, Venezuela, Bolivia, Colombia, Ecuador, Peru, Chile, and Argentina, growing extensively in the Andean altiplano...
(Stipa ichu), a muhly grass (Muhlenbergia affinis), and Muhlenbergia macroura. Small woods of Montezuma Pine (Pinus montezumae
Pinus montezumae
Pinus montezumae, known as the Montezuma Pine, is a species of conifer in the Pinaceae family.It is native to Mexico and Central America, where it is known as Ocote. The tree grows about 35 m high and 80 cm in diameter; occasionally it may reach a height of 40 m and diameter of...
) and (probably) Lumholtz' Pine (P. lumholtzii
Pinus lumholtzii
Pinus lumholtzii, the Lumholtz' Pine or Pino triste , is a species of conifer in the Pinaceae family. It is endemic to northeastern Mexico....
) occur on elevated terrain.
Status and conservation
It is highly threatened due to clearance of its habitat for creating pasturePasture
Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...
s. Its conservation status according to the IUCN is EN B1ab(i,ii,iii,v). This basically means that the species occurs on less than 5000 km², and that its range, available habitat, and population size are shrinking (BirdLife International 2004). Nonwithstanding the rediscovery of the northern population, no more than a handful of individuals are known to remain, and further research to locate additional subpopulations is urgently needed. In any case, the species will probably be uplisted to Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
soon; of the 4 subpopulations known, only one (near La Cima) seems reasonably numerous.
External links
- The distinctive song of the Sierra Madre Sparrow as an mp3 file
- BirdLife species factsheet. Retrieved 2006-JUN-11.
- Distribution of southern subpopulations. Map with Spanish captions. Retrieved 2006-JUN-11.