Nature's Neighbors ~ Rio Grande Leopard Frog

Native from central Texas, to New Mexico (where it is listed as vulnerable), south through Mexico to Vera Cruz, this frog of arid regions is highly aquatic and typically a stream dweller. However, it will utilize a variety of permanent water sources such as rivers, artificial ponds, cattle tanks, and agricultural irrigation ditches. Though seldom found away from water, they can survive short periods of dryness under rocks and by burrowing.

Adults can be 2-4 inches in length, and can be seen out during the day, but more likely at night. Active all year long except in periods of low temperature, Rio Grande Leopard Frogs shelter under rocks and in streamside vegetation. They are insectivorous, but like most frogs, will eat almost anything they can overpower and swallow.  Tadpoles feed on algae, inorganic particles, and diatoms and are strong and adapted to swimming in streams against a current.

The males make a rattling call which is loud enough to be heard a quarter mile or more away.   Mating occurs during the rainy periods of the spring and fall.  Egg masses are attached to submerged vegetation. Tadpoles have been observed over-wintering in warmer parts of their range.

Like all amphibians, they absorb much through their skin, making them extremely vulnerable to any toxin (such as herbicides and pesticides) introduced into the habitat in which they live, and are an indicator of problems with the environment.  Their greatest threats are all from humans, namely pollution, habitat destruction, and over-collection.

They are beneficial because they eat many of the insect pests that live among us and carry diseases, and in turn are preyed upon by larger animals in the food chain. We must not abuse these animals but allow them to live freely within their habitat, and appreciate the benefits they afford us.

Nature's Neighbors ~ Tarantula Hawk

This neighbor is neither a tarantula, nor a hawk, but is a very interesting insect. Both genera Hemipepsis and Pepsis are called "Tarantula Hawks".  They are indistinguishable in the field and have very similar life histories.  Four species of Hemipepsis and 15 of Pepsis are found in North America.  At least nine different species of the wasp inhabit the desert lands of the southwest. Pepsis formosa, and Pepsis thisbe, the most northern ranging, are probably the two most common.  

Tarantula Hawks occur wherever tarantulas are found and females give these wasps their common name.  Like all members of this genus, they require a spider to serve as food host for their larvae.  Male wasps engage in a behavior called "hill-topping," where they perch on taller vegetation or high points. They are strongly territorial at these sites because of the good view of the surrounding area and in particular, of females which may be receptive to mating.

Body length measures up to two inches, and are metallic blue-black with wings that are rust or mahogany, or occasionally black, in color.  This is another group of insects which have aposematic coloring – that is, conspicuous bright coloring – which warns potential predators that this is a meal that might be more painful than it is worth.  Only a few animals, Greater Roadrunners being one, eat tarantula hawks.

A female wasp finds a tarantula by running across the ground to locate a burrow to draw a spider out of, or she may also encounter a male tarantula in the open during his search for a mate.  Once stung, the tarantula is paralyzed (not killed) within seconds, and the condition will last for the remainder of its life.   If the wasp found her victim underground, she will drag it back into its own burrow and lay a single egg on the spider’s abdomen, then seal the chamber. If the wasp succeeds in stinging a male tarantula on a mating hunt, she will excavate a burrow, drag the paralyzed spider inside, lay her single egg, and seal the chamber.  After going through metamorphosis, the new adult wasp will emerge from the burrow the following season.

Tarantula hawks are most active in the summer during the day, although they avoid the highest temperatures.  The wasps consume nectar and other sugars, and they have been known to become "drunk" and unable to fly after consuming fermented fruit.  Their stings are considered to be the most painful of any North American insect, but they will ignore you and your pets, and may be observed at a very close range if they are left unmolested.  

Nature’s Neighbors ~ Western Scrub Jay/ Texas Scrub Jay

The Western Scrub Jay is a member of the Corvidae family to which various crows, ravens, and jays belong. Like its fellow corvids, they are extremely vocal, having more than 20 separate types of calls.  A year-round resident throughout West and Central Texas, this jay inhabits scrub oak and juniper woodlands as well as wooded suburban areas.  While many refer to scrub-jays as "blue jays", the Blue Jay is an entirely different species of bird not generally found in the scrub jay’s range.

Western Scrub Jays enjoy an extremely varied diet of insects, seeds, carrion, and fruit.  They also have a mischievous streak, and are skilled thieves. They’ve been seen stealing acorns from Acorn Woodpecker caches, and from others of their own species.  When these birds go to hide their own acorns, they check first that no other jays are watching.  Never one to pass up an easy meal, they will willingly come to the yard for unshelled peanuts, cracked corn and sunflower seeds.  They also enjoy birdbaths and water features.

Western Scrub-Jays are great to watch because they’re so animated.  Often found in flocks during winter, these birds are vocal and playful. During the breeding season they staunchly defend territories from other scrub-jays by flying at them, calling, and occasionally pecking or grappling. Pairs stay together throughout the year.

Recent research has suggested that Western Scrub-Jays, along with several other corvids, are among the most intelligent of animals. The brain-to-body mass ratio of adult Scrub Jays rivals that of chimpanzees and cetaceans, and is dwarfed only by that of humans. Scrub Jays are also the only non-primate shown to plan ahead for the future, which was previously thought of as a uniquely human trait.  Other studies have shown that they can remember locations of over 200 food caches, as well as the food item in each cache and its rate of decay.

Nature's Neighbors ~ Western Cottonmouth

Agkistrodon piscivorus leucostoma  is the subspecies of Cottonmouth found in the south central United States. It is the smallest of the three subspecies and tends to be darker in color.  It ranges from southern Alabama along the coast of the Gulf of Mexico, including many offshore islands, to southeastern and central Texas and north to Oklahoma, Missouri, Illinois and Indiana.  This species most well known name is Water Moccasin, but it best to not use it to avoid confusion, as there are also terrestrial moccasin species, such as the Copperhead.

Although they are found into West Texas, Western Cottonmouths are more numerous in the eastern third of the state, preferring lowland swamps, lakes, rivers, sloughs, irrigation ditches, rice fields and salt marshes, but they are not confined to living in moist habitats. Frogs, fish, smaller snakes (including other cottonmouths), small water birds, small mammals, carrion, and sometimes fish on stringers make up the cottonmouth's diet. 

Despite its formidable appearance and nasty reputation, it often chooses to flee or freeze open mouthed in threat, rather than to coil and strike. The snake's threatening gesture of exposing the white tissue of the inside of its mouth has earned its popular name. When startled, they have been known to vibrate their tails against vegetation, making you aware of their presence, they can also secrete a foul smelling musk.  As with all snakes, they avoid contact with humans or any other possible predator. But like any animal, when threatened, cottonmouths will attack to protect themselves.  Only seven percent of all Texas snakebite cases involve cottonmouths. Throughout the United States, less than one percent of all deaths by snakebite have been caused by cottonmouths.  Almost all bites by cottonmouths involve snakes purposely touched or molested in some way.

They are generally active from March through December and have also been seen on warm days in January and February. They hibernate along hillsides and upland areas above streams, usually under large roots, in burrows, or in rock crevices. In spring and fall, snakes are most active during the warmer part of the day, whereas in summer they are most active at dusk or at night. 

Nature's Neighbors ~ Honey Mesquite

Honey Mesquite is a common shrub/ small tree of the Southwest. Some specimens can grow to larger size, especially if growing in moist bottomlands.  Like many other members of the legume family, mesquite beneficially restores nitrogen to the soil.

Mesquites are deciduous and have characteristic bean pods which have long been used by humans, wildlife and livestock as a food source. It is estimated that over 75% of a Coyote's diet in late summer is mesquite beans. It is an extremely hardy, drought-tolerant plant because it can draw moisture from the water table through its long taproot, one of which was found in an underground copper mine 190 feet below ground!  It can also use water in the upper part of the ground through it’s shallow subsurface roots, depending upon availability. The tree can easily and rapidly switch from using one water source to the other. 

small specimen in arid cimate

Cattlemen regard mesquite as range weeds and eradicate them. But much of the invasion of mesquite into former grasslands where it did not grow a century ago, is ironically, due to the overgrazing of domestic cattle.  By contrast, this versatile tree has long been a welcome presence in the larders, livestock feed bins, workshops, gardens and medicine cabinets of many desert residents. 

During the inevitable droughts and deprivations of desert frontier days, the mesquite trees served up the primary food source for caravans and settlers.  During the Civil War, when groceries often ran short, mesquite beans served as passable coffee. The beans were also durable enough for years of storage and became the livestock feed of choice when pastureland grasses failed due to drought or overgrazing.  Native Americans relied on the mesquite pod as a dietary staple from which they made tea, syrup and a ground meal called pinole. They also used the bark for basketry, fabrics and medicine. Mesquite blooms, pollinated by bees, yield a very tasty honey (hence the name Honey Mesquite) and feed adult butterflies.  The leaves serve as food for butterfly larvae.

large tree near a waterway

Although often crooked in shape, mesquite tree branches, stable and durable, filled needs for wood during the construction of Spanish missions, colonial haciendas, ranch houses and fencing.  Artisans use it in the crafting of furniture, flooring, paneling and sculptures, and in some areas mesquites provide a bountiful harvest of wood for use in fireplaces and barbecue grills.

So weather you see them as an uninvited interloper or welcome neighbor, the mesquites have proven that they belong in the Southwest.

Nature's Neighbors ~ Mexican Free-tailed Bat

Mexican free-tailed bats are a medium-sized bat with short, velvety, reddish to black-colored fur, broad ears, large feet, and the end of its tail extending beyond the edge of it’s tail membrane, hence the name “free-tailed”.  They occupy a wide variety of habitats, ranging from desert communities through pinion-juniper woodland and pine-oak forests, at elevations from sea level to 9,000 feet or more. The largest U.S. populations of free-tailed bats live in the West.  The densest concentrations are found in Texas where they form maternity colonies which are found in limestone caves, abandoned mines, under bridges, and in buildings, but smaller colonies also have been found in hollow trees. It is estimated that 100-million Mexican free-tailed bats come to Central Texas each year to raise their young, the largest colony is currently found living in Bracken Cave near San Antonio, Texas, totaling over 20 million.  Nursing females require large quantities of insects that are high in fat, which they obtain by consuming egg-laden moths.

The 100 million free-tailed bats living in Central Texas caves consume approximately 1,000 TONS of insects each night.  Researchers use Doppler weather radar to watch emerging bats ascend to altitudes of 1,000-10,000 feet to feed on migrating cotton boll worm moths, army cut-worm moths, and other costly agricultural pests that migrate north from Mexico. These migratory moths hopscotch across the country each year, reaching rich agricultural land as far north as the Canadian border. The cotton boll-worm moth (a.k.a. corn ear-worm moth) alone, costs American farmers a billion dollars annually.   Although the ecological and economic impacts of large colonies are most obvious, even small colonies of bats can significantly impact local insect populations. Mexican free-tailed bats also consume enormous quantities of insects over woodlands and forests, likely including many additional pests.  

The impact of second hand pesticide poisoning of free-tails and other bats should not be underestimated, but it seems certain that this is probably not the major stress responsible for the decline of free-tailed bat populations. In a recent review of the effects of environmental contaminants on bat populations, it seems quite evident that much of the decline in free-tailed bat populations is directly due to human disturbance and roost site destruction.  It is important to preserve those colonies which still thrive. The apparent good condition of several large roosts is clearly due almost entirely to the fact that access to them is restricted by land owners who appreciate the unique resource with which they are entrusted.

Current initiatives by Bat Conservation International, The Nature Conservancy, and the Marbach family to ensure continued protection of the site of the largest known roost in Bracken Cave are to be applauded.

So the next time that you bite into that juicy ear of corn or ripe apple, remember a bat probably  played a part in bringing it to you!

Nature's Neighbors ~ June Beetle

Ever seen a hairy beetle before?  You probably have, but don’t realize it!

The "June Bug" (or May Beetles as some call them) is a member of the scarab beetle family which has approximately 1375 species in North America.  On warm spring and summer nights, these beetles are famous for bumping into your porch lights, or you if you get in the way of their clumsy flying.

They are nocturnal, but during the day they hide in the shade of leaf litter, in cracks or under things on the ground around your home to stay cool and out of sight of lizards and birds, their main predators.  The adults are  ½ to 5/8 inches long, reddish brown in color and feed on the foliage of trees and shrubs.  White "C"-shaped larvae (grubs), are up to 1 inch long, with cream-colored bodies and brown head capsules and feed on the roots of grasses and other plants.

The insects pupate (change from grub to beetle) underground in the fall.  There is one generation per year, but in colder climates, development may take two years. Adults begin to emerge in spring. During adult flights large numbers of beetles can be attracted to lights. Peak flights occur in mid to late June in central Texas, but if the weather is warm, you will start to see them as early as March.  They may cause significant plant damage if they emerge in large numbers.    

Humans who go to great pains to have “perfect” lawns may consider them a pest species, as the larvae can damage turf grasses, but as far as their natural predators in the food chain are concerned, they are irreplaceable as a food source!