Protecting Life, Large & Small

Chisos hedgehog cactus in bloom

NPS Photo

It is well known that Big Bend is located within the biologically diverse Chihuahuan Desert, but did you know that this park is home to plants and wildlife known only to this particular area? Species that are confined to a particular locality or region are known as endemics. Three species in particular, one fish and two plants, are not only endemic to the Chihuahuan Desert, but in the United States are only known in Big Bend National Park!

Big Bend gambusia, a highly endangered fish, in a researcher's measuring container during a scientific survey of the population

Dr. Sean Graham, Sul Ross State University

Tiny Fish, Tiny Habitat

The endangered Big Bend gambusia fish (Gambusia gagei), no more than two inches in length, is currently only known to inhabit four ponds at Rio Grande Village. In fact, you could literally draw a 400 yard radius around this fish’s known habitat! This fish is thought to have lived along the Rio Grande since at least the last ice-age where they adapted to feeding on invertebrates in warm spring pools and associated wetland habitats. In the 1950s, due to loss of habitat and population declines, biologists saved the five known remaining Big Bend gambusia fish. Breeding was successful, and now the entire population are descendants of these original five fish! Suitable Big Bend gambusia fish habitat exists in other locations along the Rio Grande in the US and Mexico, but further studies are needed to determine whether the fish is found at these locations.

Guadalupe fescue, a rare and protected grass during a scientific survey

Deb Manley

Rare Plants, Too

While wildlife is one of the main attractions of national parks, plants are an important component also. The Chihuahuan Desert has some of the richest variety of flora of the world’s deserts, with many notable species occuring here in the park. Among these, the Chisos Mountains are home to the only surviving population of the grass Guadalupe fescue (Festuca ligulata), known in the United States! This grass was once known in Guadalupe Mountains National Park, but hasn’t been observed for several years. The only other place Guadalupe fescue is known to grow is at one location in Mexico. Less than 200 plants have been identified in the park, and the US Fish and Wildlife Service has listed this grass as an endangered species. A second plant, the Chisos hedgehog cactus (Echinocereus chisoensis var. chisoensis), is currently listed as threatened by the US Fish and Wildlife Service. These cacti are found in grasslands and shrublands within the park, and may have been more extensive prior to the ranching era. Although comparable habitat exists in Mexico, no populations of this cactus have yet been located anywhere else. Further studies are needed to improve our management and understanding of these special plants.

Value In Every Species

Why worry about a tiny fish or one species of grass, which, if it were to disappear would hardly be noticed by most people? Protecting and valuing all species, even the smallest or weakest among us, reflects who we are as a society. Endemic species, in particular, are particularly susceptible to extinction because of their limited range and specific habitat requirements. These species are part of the amazing diversity and beauty that inspires people to travel from all over the world to visit this unique National Park.

Park Ranger Christina Rinas