Potential Impacts 

of Natural Disasters 

on South Texas Refuges

Bryan R. Winton, Refuge Manager

Lower Rio Grande Valley National Wildlife Refuge

South Texas Refuge Complex

July 24, 2007

Good Neighbor Environmental Board Meeting

Brownsville, Texas
“To administer a national network of lands

and waters for the conservation and

management of the fish, wildlife, and plant

resources and their habitats of the United

States for the benefit of present and future

generations ”

U.S. Fish & Wildlife Service

Mission of the 

National Wildlife Refuge System
National Wildlife Refuge System

South Texas Refuge Complex
1981 Satellite Image of the Valley

Santa Ana NWR
South Texas Refuge Complex Priorities

Land Acquisition

Habitat Restoration

(Tamaulipan Brushland; 11 Biotic Communities)

Wetland Management

Public Use 

Including wildlife watching, hunting, fishing, photography, 

interpretation and education

Fish & Wildlife Management/Research
Santa Ana NWR

Tropical Influence

Gulf Coast Influence

Great Plains

Influence

 Desert Influence
Chihuahuan Thorn Forest

Loma Tidal Flats

Sabal Palm

Coastal Habitat

Riparian Woodlands

La Sal Del Ray

Woodland Pothole
Santa Ana 

National Wildlife Refuge

 Established in 

1943 as a 

migratory bird 

sanctuary

 2,088 acres;

150,000 visitors 

a year

 The “Jewel” of 

the Refuge 

System
Santa Ana NWR
Plain

Chachalaca
Green Jay
Altamira Oriole
Laguna Atascosa 

National Wildlife Refuge

 Established in 1946

 130,000 visitors per 

year

 Endangered species 

monitoring

 Wetland and waterfowl 

management

 Currently 95,000 acres 

of 150,000

Redhead Duck
Kemp’s Ridley Sea Turtle

Green Sea Turtle

Loggerhead Sea Turtle
Aplomado Falcon
Lower Rio Grande Valley 

National Wildlife Refuge

 Established in 1979

 Protects habitat between 

Falcon Dam and Boca 

Chica (4 counties)

 Provides for protection of 

endangered species and 

migratory birds

 Currently 88,000 acres 

(132,500 approved)
South Texas Refuge Complex

White-tailed

Deer
Kemp’s Ridley Sea Turtle
Texas Tortoise
Hooded Warbler
Texas Horned Lizard
13-Lined Ground Squirrel
Insects:

Dragonflies, Butterflies, Moths
Natural Disasters

 Flood

 Fire

 Hurricane

 Tornado

 Disease
Flooding

 Refuge habitats along the Rio Grande 

River evolved under dynamic 

circumstances. Much more stable now. 

 Periodic inundation is important to 

maintain specific plant associations (i.e., 

Riparian Flood Forest at Santa Ana 

NWR) important to certain wildlife 

species.

 Can be detrimental/devastating now.
Flood-adapted Forests

need periodic inundation which

now, unfortunately comes only in 

the form of a Hurricane
New Arroyo near Rio Grande City


Fire Management

 Prescribed Fire and Wildfire

 Wildfires are suppressed immediately.

 Prescribed Fires are carefully planned 

intentionally-lit fires with a purpose of 

promoting plant succession, discouraging 

non-native plants, preparing the soil for a 

habitat restoration project.

 RGV is not necessarily a fire-adapted 

ecosystem. Recent grass introductions and 

subsequent infestations can increase the 

impacts of fire to native plants.
Prescribed Fire for

Marsh Management

 BEFORE
Prescribed Fire for

Marsh Management

 AFTER (During)
Prescribed Fires remove dead 

and dying plant matter, set back 

succession, and benefit natural 

systems by promoting

Regeneration -- by removing 

weak, sick, and unproductive 

individuals within a species 

(plants and animals). 
Wildfires Threaten Life, Property, and Resources

The Refuge Complex maintains Mutual Aid Agreements:

Authorizes USFWS to support as needed/requested.
Hurricane Preparedness

 Refuge Property (Data, Files, Fuel, 

Vehicles, Computers) stored at 

Moore Airfield.

 Fire Management Program to assist 

EOC (Emergency Operations 

Center) with mandatory evacuation 

(4-county).

 Agency to detail assistance poststorm as done w/Katrina & Rita.
Tornado Preparedness

 Mandatory evacuation (too little notice 

to proceed as we would with 

Hurricane warning)

 Safeguard people and property as 

best as possible considering the time 

element (typically little/no notice)

 Agency would assist local 

communities as needed/requested 

following a tornado event.
OTHER ISSUES CONCERNING 

THE REFUGE
Other Potential Disasters could occur on the refuge from

resource contamination and habitat/wildlife loss related 

to the petroleum industry.
Disease represents a form of “disaster” that concerns ranchers, wildlife 

managers, and government officials involved in fever tick eradication.

USDA Tick Eradication Program

OTHERS:

West Nile Virus

Avian Influenza

Mad Cow Disease
Human Encroachment

Development Pressure

Illegal Trespass

Dumping

..... All represent a form of Disaster 

for the Wildlife on the Refuge
Water Quality

Water Quantity
End

U.S. Fish & Wildlife Service 

 

South Texas Refuge Complex 

Rt. 2 Box 202 A 

Alamo, Texas 78516 

Phone (956)784-7500