September 8, 2011

A weekly homage to endangered species, large and small.

(Based on research by Ben Ikenson)

Houston toads are an endangered species native to the midlands of Texas. Masters of disguise, they can range in color from bluish- grey to speckled red, or even dark brown and black. These little guys don’t have powerful hind legs like frogs so they rely heavily on camouflage and their poisonous skin secretions to protect them from predators. Adult females grow up to four inches long (males are slightly smaller). During scorching hot summers and bitter winters, the toads bury their tiny bodies under loose sand and hibernate to protect themselves from the extreme weather.

Unfortunately, one threat these miniature marvels can’t seem to outwit is industrialization. Rapid development in Houston, Texas and the surrounding areas has destroyed much of the toad’s habitat. Wetlands were replaced by roads, and forests were replaced by shopping centers as cities grew. By the 1960s, the toads had seemingly vanished. Once thought to number in the tens of thousands, some researchers estimated that there were as few as 3,000 Houston toads remaining. In 1970, they were federally listed as an endangered species with habitat loss cited as the primary cause of decline. Some isolated populations of the toad in and around Houston had been completely wiped out. And although the toads are now protected under the Endangered Species Act, the largest remaining population in Bastrop County is still under intense threat from urban development according to reports from the U.S. Fish and Wildlife Service.


Cartoon by Bruce PlanteYou’ll probably never hear a doctor say “lick two toads and call me in the morning,” but toads are known to carry toxins that are pharmaceutically important. Many modern medicines contain active ingredients derived from these chemicals. The Houston toad in particular, secretes valtrex online serotonin—an essential chemical in our brains—and alkaloids used to treat heart and neurological disease. The alkaloids are thought to have analgesic properties quite possibly more powerful than morphine.

Of course, their chemical cures aren’t their only talent. Houston toads help manage the ecosystem by keeping the insect population down. And despite their many defense mechanisms, spiders, raccoons, turtles, snakes, owls, and even fire ants have been known to prey on the amphibians. However with so few toads to study, it’s hard for scientists to accurately estimate the Houston toad’s impact on the environment. Often toads provide key linkages in nutrient cycles because they carry substances from the water to land during metamorphosis from the tadpole stage to being fully terrestrial adults.

As studies continue, Houston toads might prove valuable in other ways to the environment and for practical uses like medicine.

Still despite their helpfulness, urbanization and even agricultural development continue to intrude on the toad’s habitat. Recently more and more forests have been turned into fields or pastures for farming. Unfortunately, livestock often overgraze these areas and leave the toads with little resources for food and shelter. But there are ways that people can help. Replanting native bunchgrasses instead of sod-forming plants and limiting livestock numbers can help the toad’s populations grow in these areas. The Texas Parks and Wildlife Department and USFWS jointly prepared a brochure for private landowners who wish to implement their agricultural practices in ways that are compatible with the needs of the Houston toad. With the assistance and involvement of a dedicated community, perhaps these little amphibians will be able to make the leap from brink of disaster to the threshold of recovery.

Recently, wildfires have raged throughout Bastrop State Park–considered the last remaining stronghold for the Houston toad. Read the  full article here.


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