Animals

Birds

Amistad National Recreation Area has documented over 200 different species of birds, both native and migratory. The Natural Resources Division has been participating in yearly banding projects spanning five years in order to document bird species, breeding patterns, and migration routes. The information obtained by these banding sessions allows the park staff to monitor birds and offer insight to the average birder. Educational opportunities for birders are provided with Bird Walks among the riparian zones. Many different species utilize the resources at Amistad Lake during migration and breeding seasons, which makes this program interesting to young and old alike. Interior Least Terns use Amistad Lake as a breeding ground during late spring. The Interior Least Tern has been listed on the Endangered and Threatened list for several years. The Natural Resources Division monitors the Least Terns to help ensure that the species has a future

Amphibians

 
Though the hot, dry climate of the Trans-Pecos region may not seem the ideal environment for amphibians, nine species have been identified within the park’s boundaries. Among these are the Couch’s Spadefoot Toad, Rio Grande Leopard Frog and the Great Plains Narrowmouth Toad.
Because amphibians lack the ability to generate body heat, they must rely on the environment to regulate their body temperature. During the day many amphibians will attempt to escape the heat by hiding in rock crevices, under plants or by burrowing into the soil. The Great Plains Narrowmouth Toad has even been known to use rodent and tarantulas burrows to escape the heat.

Frogs and toads are the most commonly found amphibians within the park. Though very similar in appearance, frogs generally have smooth skin, long legs, and bulging eyes while toads are characterized by bumpy skin and short legs. Neither frogs nor toads have fur, feathers or scales of any kind.

Primarily nocturnal, amphibians can be difficult to spot, and are most easily seen at twilight or at night with the help of a flashlight. Each species has a distinctive call, or voice, that can be used to identify it from other species. The guttural trill of the Rio Grande Leopard Frog is easily distinguishable from the bird-like call of the Red-spotted Toad.

Remember, all amphibians are protected against harassment, killing or collecting within park boundaries. Visitors are not permitted to handle or disturb amphibians in any way.

Animals

Mammals are common, but since most animals are secretive, visitors usually see white-tail deer, cottontail rabbits, jackrabbits, and perhaps an occasional skunk or porcupine.

Like the flora, Amistad's fauna also represents an area of transition. Many tropical species, especially birds, are at or near their northern limits. Great kiskadees (a flycatcher), olive sparrows, and two tropical kingfishers, the ringed and green, can be seen in the Amistad area. Tropical butterflies, like the white peacock, ruddy daggerwing, common mestra, and the polydamas swallowtail may be found.

Perhaps Amistad NRA's greatest wildlife phenomenon is the fall migration of Monarch butterflies. Around October, just after the first major autumn cold front, thousands of Monarchs pass through this part of Texas on the way to their wintering grounds in the mountains of central Mexico. They roost in trees in the hundreds, waiting for favorable winds from the north to help them on their journey south.

Reptiles

Unlike many birds and insects, which appear in the park only seasonally or cyclically, reptiles can be seen at Amistad National Recreation Area nearly year round. Of the four main orders of reptiles, three can be found in the park.
  Thirty-seven individual species of reptile have been sighted and verified within the boundaries of Amistad NRA; 18 more species are known to live in the area but sightings within the park have not been confirmed. Three reptiles currently found within park boundaries, the Texas indigo snake, the Trans-Pecos black-headed snake and the Texas horned lizard, are listed on the state protected or threatened species list.
  Though reptiles may have descended from amphibians some 315 million years ago, modern reptiles and amphibians differ in several crucial anatomical and behavioral ways. Most importantly, reptiles are far less dependant on water for survival. While the thin, moist skin of amphibians dehydrates easily, a reptiles scaly skin helps it to retain moisture longer allowing it more freedom of range. The hard, protective cover on reptile eggs means that they do not need to reproduce in water as amphibians do. Also, reptile young generally resemble their parents while the offspring of amphibians more closely resemble fish.
  Because reptiles are ectotherms (cold-blooded) they are unable to generate enough body heat to maintain a constant, internal temperature. In order to regulate their body temperature they must gather heat from the environment to stay warm and seek out shady places to cool down. This the main reason why you will see turtles and lizards “basking” on rocks in the sun. It is also the reason why many snakes can be found under rocks or low vegetation during the day.
  Of the 37 reptile species known to be living in Amistad National Recreation Area, 12 are species of snake, 13 are lizard species and three are species of turtle. Though snakes have something of a bad reputation, they will generally only bite in self-defense. Take care when walking through densely vegetated areas or over loose rock and always wear protective footwear.
  Remember, all reptiles are protected against harassment, killing or collecting within park boundaries. Visitors are not permitted to handle or disturb reptiles in any way.

Insects, Spiders, Centipedes, Millipedes

A big attraction for nature lovers at Amistad is the fall Monarch butterfly migration. Year after year, thousands of Monarchs roost in the same few trees as they head to their wintering grounds in Mexico.