RIO GRANDE VALLEY, Texas (ValleyCentral) — This year marks the 50th anniversary of perhaps the nation’s most important wildlife conservation law protecting species at risk, such as the rare and elusive ocelot prowling the brush country of southernmost Texas.

Since Congress passed the Endangered Species Act or ESA in 1973, 1,678 species in the United States have been listed as threatened or endangered with 105 of those, like the Aplomado Falcon, currently receiving protection in Texas.

The ESA, which is administered thru the Interior Department’s U.S. Fish and Wildlife Service, provides special provisions that protect critical habitats of species at risk while also prohibiting harm to them.

While not only safeguarding threatened wildlife on federal lands, the U.S. Fish and Wildlife Service also works with private landowners in South Texas, like rancher Frank Yturria who created a vital ocelot preserve on family property.

The Endangered Species Act has been extremely successful in saving 99% of species under its protection from extinction, and 55 species have recovered sufficiently to be delisted and taken off the endangered species list.

Perhaps, the most notable success is the restoration of America’s National Bird the Bald Eagle which was delisted in 2007. Since then, the remarkable recovery of the Brown Pelican was achieved in 2009, and the Peregrine Falcon was delisted in 1999 thanks in great part to the banning of the harmful pesticide DDT.

And, just this month, the Wood Stork, which migrates through the Rio Grande Valley, has been proposed for delisting.

These prehistoric-looking birds, with long legs and baldheads, were first listed as endangered in 1984 after their numbers declined by 75 percent.

Thanks to wetland restoration efforts and enhanced protection, they now nest throughout the coastal plains of Florida, Georgia, and the Carolinas, and their numbers have swelled to 11,000 nesting pairs.