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Adaptations for Texas Ecology

Biomes in Texas vary, from the deserts in the Basin and Range region, to grasslands, to subtropical forests, to the aquatic biome of the Gulf of Mexico. Like the flora, the fauna of the state of Texas are adapted to these diverse ecological environments.

Many animals avoid the extreme daytime temperatures of the desert biome and are active only at night. Many snakes, lizards, and salamanders increase their activities at night when temperatures are relatively cool and humidity is at its lowest. Animals that are active during the day rely on rocks and shrubs for shade. Some animals have adaptations that eliminate heat and excess salt from their bodies.

The climate in the grassland biome is usually hot and dry. Precipitation is very irregular. Many small animals, such as the prairie dog, burrow in to the soft soil of the grassland to stay cool. These animals often obtain much of the water they need from their food.

Large numbers of insect species are found in the subtropical biomes. Insects and other invertebrates are highly adapted to living in wet areas. Mosquitoes and dragonflies, for example, live underwater in their larval stages. During this phase of metamorphosis, mosquitoes use tubes that extend above the water level for breathing. Dragonflies breathe through gills during their larval stages. The water boatman has one pair of legs that is modified into paddles.

These paddles allow the insect to catch underwater prey. The water boatman also is adapted to swim to the surface of the water to trap needed air behind its wings. Water striders have legs adapted to allow them to stay afloat on the surface of the water.

The saltwater biome of the Gulf of Mexico supports many forms of life. Among these are sponges, mollusks, arthropods, and chordates. All these animals are adapted to the aquatic biome. For example, bony fish, which belong to the Osteichthyes class of the Phylum Chordata, use gills to obtain oxygen from the water in which they live. Their fins and a back and forth movement of the body enable them to swim. A mucous covering protects them from diffusion of water into their bodies. Fish common in the waters off the coast of Texas include red snapper, flounder, red drum and sea trout.

In addition to adaptations that enable them to withstand physical changes in their environments, animals have adaptations that protect them from predators. Specialized body parts and certain behaviors are animal adaptations for protection. For example, the nine-banded armadillo, an animal common in Texas, isprotected from most of its predators by the hard, protective armor that covers its upper body. In addition to its toughness, the armor is hinged so that the animal can curl up into a ball to protect its soft parts from an attacker.

Camouflage is an adaptation that allows an animal to blend into its surroundings. The bittern is a bird that uses camouflage to resemble the cattails among which it lives. Countershading is a type of camouflage in which the underside of an animal is lighter in color than the upper side. Many birds of Texas use countershading to avoid predators.

The Texas pronghorn antelope and deer, among others, have long legs that are adapted for speedy escape from predators. These animals generally graze in open fields and can avoid attackers by their ability to run fast. Other animals, including the peccary and the skunk, will fight back when attacked by a predator. The peccary, similar to the domestic pig, will attack a predator to save itself or its young. Such an attack often frightens away a predator. Skunks, as you might imagine, are rarely attacked more than once by the same predator! The scent emitted by the skunk is so powerful that predators are reluctant to attack any skunk again.

Certain behaviors are also adaptations used by animals as protection from harm. The killdeer and the opossum, for example, feign injury and death to avoid attacks. The killdeer is a bird that fakes a damaged wing or leg when a predator approaches its nest. Once the predator has been lured far enough away from the nest, the killdeer quickly

“heals” and flies away. The opossum, on the other hand, plays dead to ward off an attacker. When a predator such as a dog or coyote comes upon the “dead” animal, it walks away, allowing time for the opossum to escape up a tree.

1.

How are animals that live in the deserts of Texas adapted to their environments?

2.

How is the Texas prairie dog adapted to the grassland biome?

3.

How are insects adapted to wet environments?

4.

How are chrysalises adapted for dry regions?

5.

How does the armadillo protect itself from predators?

6.

How might countershading protect a bird perched in a tree from predators below?

7.

What is meant by the phrase “playing opossum”?

8.

Prairie dogs live in groups called colonies. Underground tunnels in the colony are interconnected. How might this behavioral adaptation enable them to avoid predators?

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