Flora:
* Desert plants: Adapted to the harsh conditions, these include cacti (prickly pear, cholla, barrel cactus), agave, yucca, ocotillo, and desert shrubs.
* Riparian vegetation: Along the Rio Grande and its tributaries, trees like cottonwood, willow, mesquite, and ash thrive.
* Grasslands: The Chihuahuan Desert grasslands are home to various grasses like grama, buffalo grass, and blue grama.
* Pine forests: At higher elevations, ponderosa pine and juniper forests provide a different habitat.
Fauna:
* Mammals:
* Large mammals: Mountain lion, black bear, javelina, mule deer, pronghorn antelope, bobcat, and desert bighorn sheep.
* Smaller mammals: Bats, rabbits, squirrels, rodents, and foxes.
* Birds:
* Birds of prey: Golden eagle, ferruginous hawk, red-tailed hawk, and kestrel.
* Songbirds: Cactus wren, roadrunner, hummingbird, and numerous migratory species.
* Waterfowl: Ducks, geese, and other waterbirds can be found near the river.
* Reptiles:
* Snakes: Rattlesnakes, garter snakes, and other non-venomous species.
* Lizards: Lizards like the Texas horned lizard, chuckwalla, and whiptail lizard.
* Turtles: Sonoran mud turtle, and Texas tortoise.
* Amphibians:
* Frogs and toads: The Rio Grande leopard frog and other species thrive in the park's wetter areas.
* Insects:
* Butterflies: A variety of butterflies, including the monarch, can be observed.
* Beetles: The desert is home to many beetle species.
* Ants and other insects: A diverse insect population contributes to the ecosystem.
Other Biotic Factors:
* Microorganisms: Bacteria, fungi, and other microorganisms play crucial roles in decomposition and nutrient cycling.
* Plant communities: The diverse vegetation provides habitat and food sources for various animals.
* Predator-prey relationships: The complex interactions between predators and prey help to maintain a balanced ecosystem.
* Competition: Plants and animals compete for resources such as water, sunlight, and food.
These are just a few examples of the biotic factors found in Big Bend National Park. The park's unique combination of desert, riverine, and mountainous habitats creates a rich and diverse ecosystem with complex interactions between its living components.
