The changes primarily alter two of the main sections of the ESA: Section 4, which deals in large part with adding species to or removing species from the act's protection; and Section 7, which covers consultations with other federal agencies.
Conservation groups reacted in dismay, saying the rollbacks would pave the way for the gradual destruction of a listed species' habitat as long as each individual step was sufficiently modest. That animal depends on spring snowpack for mating.
The administration's rollbacks, which sparked a torrent of public opposition, come just months after a dire United Nations report warned that human activity has pushed a million plant and animal species to the brink of extinction.
The Department of Interior says its aim is to increase clarity, consistency and efficiency.
"The best way to uphold the Endangered Species Act is to do everything we can to ensure it remains effective in achieving its ultimate goal - recovery of our rarest species", Bernhardt said.
The new rule has drawn criticism from the country's conservationists and environmentalists.
Numerous environmental groups and state attorneys general vow to sue the administration over the changes, alleging they are illegal because they're not grounded in scientific evidence.
The new regulations, which were discussed in what little detail the press conference would allow, include changes to the way critical habitat is determined, limitations on protecting species based on "speculative" future threats (e.g., climate change), consideration for some economic interests when considering species protections, and changes in the way threatened species (those likely to become endangered) are managed.
Kim Thorburn, state Fish and Wildlife commissioner, said the decision could have dire consequences, though she noted species listed by the state would continue to be protected.
Alaska Republican Rep. Don Young said he is the only now serving member of Congress who voted for the original Endangered Species Act of 1973 and that the courts since then "have turned it into a bureaucratic nightmare that could not have been anticipated".
"We are in the midst of an unprecedented extinction crisis, yet the Trump Administration is steamrolling our most effective wildlife protection law", said Rebecca Riley, legal director of the nature program at the Natural Resources Defense Council. Other changes address designation of critical habitat with the goal of reducing "the potential for additional regulatory burden that results from a designation when a species is not present in an area". This disregards the cumulative "death-by-a-thousand-cuts" process that is the most common way wildlife declines toward extinction.
The Endangered Species Act, which Republican President Richard Nixon signed into law in 1973, protects more than 1,600 plant and animals species today, and is credited with saving the California condor, the Florida manatee, the gray whale and grizzly bear among others.
"We'll see the Trump administration in court", said Caputo.
The groups says that lifting the regulations will help "encourage states and landowners to recover [threatened species] before they reach endangered status". "According to the Center for Biological Diversity", she wrote, "there have been at least 419 "legislative attacks" - that is, actions meant to weaken federal protection of endangered species - against the Endangered Species Act since 1996, 116 of which occurred during the current 115th Congress".