When rains pushed the Rio Grande River to flood stage in 2010, an existing border wall acted as a flood barrier, protecting some lowlands but also trapping some animals. A 2011 U.S. Fish and Wildlife Service report obtained through a Freedom of Information Act request by the Sierra Club noted the discovery after the flooding of shells from “hundreds” of Texas tortoise, which that state lists as a threatened species.
“Animals caught between the river and the flood wall that could not escape around the edges of the floodwalls likely perished,” said the report. Endangered species like the ocelot and jaguarundi, both small wildcats, also might have died, according to the report.