Free and Sovereign State of Coahuila de Zaragoza

Coahuila is one of the 32 states of Mexico. It borders the Mexican states of Nuevo León to the east, Zacatecas to the south, and Durango and Chihuahua to the west. To the north, Coahuila accounts for a 512 kilometres (318 mile) stretch of the Mexico–US border, adjacent to the US state of Texas along the course of the Rio Grande (Río Bravo del Norte). With an area of more than 151,500 square kilometres (c. 58,500 square miles), it is the nation’s third-largest state. It comprises 38 municipalities (municipios). Coahuila has a population of over 3.25 million inhabitants. The largest city and State Capital is the city of Saltillo with over a million inhabitants; the second largest is Torreón (but is the largest metropolitan area in Coahuila and 9th largest in Mexico with c.1.5 million people).The Sierra Madre Oriental runs northwest to southeast through the state, and the higher elevations are home to the Sierra Madre Oriental pine-oak forests. East of the range, the land slopes gently toward the Rio Grande, and is drained by several rivers, including the Salado and its tributary the Sabinas.

Bolsón de Mapimí Biosphere Reserve – ©José Antonio Aranda Pineda CC BY-SA 4.0 via Wikimedia Commons

The Tamaulipan mezquital, a dry shrubland ecoregion, occupies the western portion of the state, and extends across the Rio Grande into southern Texas. The portion of the state west of the Sierra Madre Oriental lies on the Mexican Plateau, and is part of the Chihuahuan Desert. The Bolsón de Mapimí is a large endorheic basin which covers much of the western portion of the state and extends into adjacent portions of Chihuahua, Durango, and Zacatecas. The Nazas River, which flows east from Durango, and the Aguanaval River, which flows north from Zacatecas, empty into lakes in the Bolsón. Torreón, the most populous metropolitan area in the state, lies on the Nazas in the irrigated Laguna Region, the (Comarca Lagunera), which straddles the border of Coahuila and Durango. The state is largely arid or semi-arid, but the rivers of the state support extensive irrigated agriculture, particularly cotton. The Parras district in the southern part of the state produces wines and brandies. The pine-oak forests of the Sierra Madre produce timber.

Birding Coahuila

The state contains two biosphere reserves. Maderas del Carmen lies on the northern border of the state, and includes sections of the Chihuahuan desert and sky islands of pine-oak forest in the Sierra del Carmen.

The springs, lakes, and wetlands of Cuatro Ciénegas lie west of Monclova on the west slope of the Sierra Madre.

Being a large state with a relatively small population, which is largely urban, much of the state is undeveloped and there is still room for wildlife, albeit in places an inhospitable environment. Nevertheless, large predators like Black Bear and Puma inhabit the wilder areas as do herbivores like Pronghorn a relative of antelopes.

A Cuatro Ciénegas  spring – ©Chanilim714 CC BY-SA 3.0 via Wikimedia Commons

Some areas, isolated in the Chihuahuan desert, such as the oasis valley of Cuatro Ciénegas is rich in wildlife including many endemic species. Eight hundred eighty-five animal species have been described and classified in the Cuatro Ciénegas valley, 38 of which are endemic (mollusks, crustaceans, scorpions, dragonflies, fish, reptiles, and amphibians). There are no birds endemic to the state but is home to half a dozen endemics and a wide range of arid area specialists.