Content by Wildernet
On the Big Slough Auto Tour, over 7 miles of gravel roads and ten interpretive stops are provided in a variety of wildlife habitats. These provide opportunities to observe wildlife and learn marsh ecology. Facilities available on the tour include observation platforms, exhibits, birding trails, picnic shelter, photo blind, and a restroom. Wildlife viewing is best in the early morning and late evening during both the winter waterfowl concentrations and spring and fall migrations of songbirds and shorebirds.

Stop #1: Big Slough: A Freshwater Lifeline Through the Marsh

The body of water on the left is Big Slough. You will come across it several times during the tour. A slough is a muddy body of water that normally does not flow. This ancient sandy stream bed provides an excellent habitat for herons, wading birds, and migratory waterfowl. Two of the most common birds seen in the slough are the American coot (white bill) and common moorhen (red bill).

Stop #2: Gator Nest Pond

Openings in bulrushes are "gator holes." Alligators 'dig' with tail and snout to create dens and deepen the pools. When it is very dry these gator holes may be the only remaining water in the parched wetland. The fish, insects, and crustaceans that collect in these gator holes repopulate the marsh when the rain comes again. Wading birds gather at these oases to feed on the concentration of organisms.

Stop #3: Water Wonders: Olney Pond

You are driving on a complex system of dikes that impound and release water. The water level is lowered in the summer to encourage the growth of different types of plants. These plants support a wide variety of waterfowl that arrive in the fall after the impoundment is reflooded.

Watch for eyes in the water; there may be an alligator under them. The ditches along the auto tour at first seem like lifeless pools of rainwater; however, if you were to scoop up a cup of water and put some under a microscope, you would discover a world of miniature life. The thousands of tiny aquatic organisms are a basic step in the food chain, providing large quantities of protein, essential in the diet of ducks and shorebirds.

Stop #4: Nature's Nursery: A Salt Marsh

Nearly all marine organisms owe their existence directly to marsh areas. Fed by both salt and freshwater, salt marshes are among the most fertile areas on earth; twice as productive as the best farmland! The marshes are nurseries for the young of many species of shrimp, crabs, crustaceans, and fish. Stands of smooth cordgrass are a prominent feature in this great expanse. The cordgrass is home to snails, clams, and crabs, which in turn feed other species such as mice, raccoon, and terrapin. Bird species characteristic of this marsh include rails, sparrows, marsh wren, mottled ducks, blue-winged teal, bitterns, herons, and red-winged blackbirds.

The large open areas are called mud flats. When the water is high, herons, spoonbills, and cormorants are common.When the tide is out, the mudflats are exposed, providing feeding habitat for probing shorebirds such as willets, curlews, and dowitchers. Their feast includes worms, shrimp, and crabs.

Stop #5: A Fly-in Cafe and Motel: Rodgers Pond

Rodgers Pond offers a place for wintering waterfowl to rest and feed, away from predators and human disturbance. Ducks, egrets, and ibis eagerly feed upon and among the submerged plants. With plentiful food and water only a bill's length away, the need for shelter is comfortably met by cattails and bulrush.

Waterfowl, like all living things, have certain requirements that must be met or they will not survive. You have the same basic requirements: water, food, and cover. This is called habitat. It is the job of wildlife managers to know the habitat needs of animals and to provide and maintain a variety of quality habitats.

Look for tugboats moving barges in the distance. They are moving up and down the Intracoastal Waterway just beyond the far side of the pond. East of the waterway is Christmas Bay Coastal Preserve, one of the last pristine bays on the Texas coast and the northernmost range of the sea grass beds. Sea grass beds are extremely endangered and vulnerable on the upper coast of Texas. They are an important source of food for redhead ducks and provide food and cover to many marine organisms.

Stop #6: Nature's Recyclers

Fire is nature's way of returning many nutrients to the soil. Although lightning-caused wildfires do occur, most often fires are set by refuge staff to change the vegetation type, reduce or remove unwanted plant species, improve quantity and quality of food for wildlife, and remove large accumulations of fuel.

Grazing cattle maintain stages of vegetation that are productive for wildlife. On Brazoria, grazing reduces vegetation heights so geese and sandhill cranes can more easily forage on the plant roots. Limited grazing creates a diversified habitat.

Stop #7: Cox Lake

Look for alligators on the banks or in the water. This part of Big Slough is one of the last areas to dry up in a drought and therefore it often attracts alligators. The large body of saltwater beyond the slough, Cox Lake, is state-owned and not part of the Refuge. Fishing by boat is permitted in Cox, Alligator, Nicks, Salt, and Lost Lakes. The structures you see are privately owned fishing cabins.

Stop #8: Teal Pond - Wildlife Viewing Platform

The Texas gulf coast is the primary wintering area for most of the Central Flyway waterfowl. The coastal salt marshes are the ancestral wintering grounds of the lesser snow geese. These geese, along with smaller populations of Canada and white-fronted geese, usually reach peak numbers of 50,000 on the refuge during December and January. Toward Teal Pond you may notice large concentrations of geese gathering in the early morning and late evening during the winter. The geese are taking grit (gravel) to aid in digestion. Hawk, harriers, kestrels and white-tailed kites are frequently seen here.

Stop #9: Munching in the Marsh

Notice the variety of birds using the slough and their different ways of feeding. Shovelers use their large bills to strain the water for aquatic organisms, while the gadwalls and pintails tip forward to feed on the bottom of shallow ponds. Ruddy ducks dive into the deep water to feed on bottom vegetation. The long, curved bill of the ibis aids in sweeping and probing the mud for crustaceans.

Stop #10: Discover Big Slough Trail

Hike this trail to learn more about a freshwater marsh and get an up-close view of birds and alligators. This birding trail, which follows the slough, leads past openings in the bulrush. Allow a minimum of 45 minutes. Be prepared for the salt marsh mosquitoes! These annoying but important critters are part of the marsh food chain. Mosquito larvae provide valuable food for birds and fish. Look closer at the plants around you! Cattails are emergent plants (they grow sticking up out of the water). Cattails can be used for food, torches, mattresses, and flower arrangements.

Stop #11: Salty Prairie Search

Look for evidence of a number of creatures who live here: crayfish chimneys; tracks and droppings of bobcats, coyotes, raccoons, and mice. The land on both the north and south sides of the access road is salty prairie. The dominant vegetation in this area is gulf cordgrass, which is important for mottled ducks nesting habitat.

Since wildlife and people must share the same environment, our goal is to manage Brazoria National Wildlife Refuge so that you may observe and study wildlife without disturbing it or its habitat.

Please stay on the designated tour route. Your vehicle makes an excellent blind. You are welcome to explore the foot trails, but be aware that alligators and poisonous snakes live here; please keep your distance. You will find binoculars, spotting scope, camera, field guides, and mosquito spray helpful.

Directions: From Angleton, TX, From the intersection of State Highway 35 and FM 523. Take FM 523 for 4 miles to Highway 2004 intersection. Continue on 523 for 5.5 miles to County Road 227. Turn left and proceed 1.7 miles to refuge entrance.

  • Be the first to Review
Your rating for Big Slough Auto Tour
Tell others why (optional):
You have 850 characters left.

Brazoria National Wildlife Refuge

Visitor Information

Telephone Number: 979-233-5338
The details, dates, and prices mentioned here were accurate at the time of publication.

Review by Wildernet Copyright © 2010 all rights reserved.