The Lower Rio Grande Valley National Wildlife Refuge is a National Wildlife Refuge

National Wildlife Refuge

National Wildlife Refuge is a designation for certain protected areas of the United States managed by the United States Fish and Wildlife Service. The National Wildlife Refuge System is the world's premiere system of public lands and waters set aside to conserve America's fish, wildlife and plants...

 in Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

.

Here, on the international border between the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and 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...

, a host of nature's borders converge - climate, community, land form and geography. Only 5% of the native landscape remains on the lower

Rio Grande Valley

The Rio Grande Valley or the Lower Rio Grande Valley, informally called The Valley, is an area located in the southernmost tip of South Texas...

 Rio Grande

Rio Grande

The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...

 and its nearby reaches, yet the diversity within these fragments adds up to an astonishing 1,200 types of plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s, 700 species of vertebrate

Vertebrate

Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds...

s (including nearly 500 bird species) and 300 kinds of butterflies

Butterfly

A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

. Eleven different biological communities exist on the refuge, from the Chihuahuan thorn forest to tidal wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

s.

Numbers alone cannot depict the true value. A rare Ocelot

Ocelot

The ocelot , pronounced /ˈɒsəˌlɒt/, also known as the dwarf leopard or McKenney's wildcat is a wild cat distributed over South and Central America and Mexico, but has been reported as far north as Texas and in Trinidad, in the Caribbean...

 merges with the shadowy brush. A pair of Northern Caracaras glides above the river. A Mexican Bluewing Butterfly (Myscelia ethusa

Myscelia ethusa

The Mexican Bluewing or simple Blue Wing is a species of butterfly of the Nymphalidae family. It is found from Colombia north through Central America to Mexico. Strays can be found up to the lower Rio Grande Valley of Texas in the United States.The wingspan is . There are many generations per...

) flutters into view, while Great Kiskadee

Great Kiskadee

The Great Kiskadee, Pitangus sulphuratus, is a passerine bird. It is a large tyrant flycatcher; sometimes its genus Pitangus is considered monotypic, with the Lesser Kiskadee The Great Kiskadee, Pitangus sulphuratus, is a passerine bird. It is a large tyrant flycatcher; sometimes its genus Pitangus...

s cry an insistent "kis-ka-dee, kis-ka-dee".

The refuge is designated as part of the Great Texas Coastal Birding Trail

Great Texas Coastal Birding Trail

The Great Texas Coastal Birding Trail is a state-designated system of trails, bird sanctuaries, and nature preserves along the entire length of the Texas Gulf Coast in the United States. As the state of Texas hosts more bird species than any other in the U.S. the trail system offers some of the...

, a network of wildlife viewing sites throughout the Texas coastal regions.