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Houston Toads Released into the Wild
Endangered Houston Toads Get a Head Start This Fall - With Help From the Houston Zoo
September 18, 2009
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Recent rains in Central Texas not only watered residential lawns and filled ranch cattle tanks, but also brought much needed relief to one of the most imperiled species in Texas - the endangered and elusive Houston toad, Bufo houstonensis. Ironically named the Houston toad, it disappeared from Harris County by the 1970’s. Historic prolonged droughts, rapid urbanization and habitat loss are among the reasons for the toad’s decline.
A true Texas native, the Houston toad is found nowhere else in the world, only in the deep sandy soils and the pine and oak forests of a few counties in east central Texas. Bastrop County is the species’ final stronghold, but studies suggest its population is in decline. Sadly, trends indicate we are silently losing this part of our natural heritage and once it is gone, it is gone forever. However, a recovery team of government agencies, nongovernmental organizations, Texas State University, the Houston Zoo and private landowners is working to return the Houston toad to its historic range.
On Sep. 21, toads were released into the wild at Bastrop State Park. The head start program to hatch wild eggs and then rear juvenile toads in captivity and release them in the wild is just one component of a broader recovery effort for the species. A key point is this: no matter how many toads are raised and released, the species will not survive without good habitat.
In the spring of 2007, the Houston Zoo began receiving egg strands from the Bastrop County Houston toad population, collected by Texas State University. The eggs were hatched at the zoo, transported back to Bastrop County and released at the exact same location. Researchers are careful to keep toad eggs separated, so they can return adult toads back to the same breeding pond where the egg strands were collected. A series of toad releases into the wild has since taken place in 2007, 2008 and earlier this year. This type of conservation program is known as Head Starting. The plan is to give the toads a fortunate beginning – a “head start” - helping them survive through the most hazardous stage of their existence, allowing them to mature and create more Houston toads.
Houston toads are known to be “explosive breeders,” appearing in large numbers at breeding ponds where males chorus to attract females over a few nights during the breeding season. This season usually peaks in March and April. Breeding activities are believed to be triggered by rainfall, warm night time temperatures and high humidity. A good rain can create temporary ponds and fill existing ponds allowing the toads to breed and deposit eggs. Eggs are deposited in strings in the water, and hatch into tadpoles that develop into juvenile toadlets about 60 days after being deposited. Large numbers of eggs are produced, but each egg has less than a one percent probability of survival.
Houston toads are known to be “explosive breeders,” appearing in large numbers at breeding ponds where males chorus to attract females over a few nights during the breeding season. This season usually peaks in March and April. Breeding activities are believed to be triggered by rainfall, warm night time temperatures and high humidity. A good rain can create temporary ponds and fill existing ponds allowing the toads to breed and deposit eggs. Eggs are deposited in strings in the water, and hatch into tadpoles that develop into juvenile toadlets about 60 days after being deposited. Large numbers of eggs are produced, but each egg has less than a one percent probability of survival.
The toad’s continued existence depends on partnerships between the Houston Zoo, United States Fish and Wildlife Service (USFWS), Texas Parks and Wildlife Department (TPWD), Texas State University, Environmental Defense Fund, Lost Pines Habitat Conservation Plan and especially the private landowners that manage their land in the best interest of the toad and its habitat.
Bastrop State Park has steadily expanded in recent decades, recently adding land through grants and donations in areas specifically acquired to provide Houston toad habitat. The park has expanded from almost 3,500 acres in 1979 to close to 6,000 acres today. Also, project partners have assembled a half dozen or more private landowners with more than 7,500 acres of occupied toad habitat in Bastrop County into an overall strategy of habitat improvement using prescribed burns and other actions, with plans to release headstarted toads into the improved habitat.
TPWD awarded a Landowner Incentive Program (LIP) grant to fund Houston toad recovery in 2007 totaling about $230,000, about 43 percent of which was government funding and the remainder was matching contributions from landowners, Environmental Defense Fund and the Houston Zoo. This year, private landowners submitted four new LIP grant applications for Houston toad recovery, applications now being reviewed for grant awards that will be made later this fall.
Proud Texas landowners are making a difference by actively working toward watershed restoration, forest management and improving pond quality by modifying grazing and access regimes for livestock. For example, Jim Small of Bastrop and his family have been stewards of the toad since the 1980s, when the first efforts to breed the species began. Since then, out of an awareness of the toad and a strong stewardship ethic, Jim and his family have improved habitat quality by prescribed fire, selective tree thinning and excluding cattle from active Houston toad breeding areas.
After obtaining a safe harbor agreement with the USFWS, Jim and his family now seek to increase their efforts on behalf of the toad and are implementing strong wildlife research and stewardship programs to benefit the toads. To make good land management feasible, financial support and incentives are available through state, federal, local government and private programs so property owners do not have to shoulder the financial burden alone. Landowners like the Small’s have taken ownership of the restoration of the toad and will be the key to bringing this species back from the brink of extinction.
The Bob Long family, owner of Round Bottom Ranch in Bastrop County, has also been part of the private landowner partnership working to protect the toad since 2002. The Longs received a LIP grant in 2004 for toad habitat restoration, and this April they received a TPWD Lone Star Land Steward award in the Pineywoods ecoregion category to recognize their longstanding contributions.
