Species Recovery

The  Endangered Species Act of 1973 was passed to protect plants and animals that are considered at risk of extinction. The ultimate goal is to recover populations to a sustainable level. How is this achieved?
The first step is to study the situation. Without knowing why a species is in decline, it may be difficult to figure out how to save it. The end result of studying would be a recovery plan.
Recovery plans outline what needs to be done and how to go about doing it. One key component is identifying and protecting critical habitat. Without having adequate habitat there is no way to protect the species.

Rare California condor, flying in the wild again since 1996
(NPS)

There are a few ways to recover a species. The most obvious is to prohibit killing it. Putting a stop to human-caused deaths is the first step in halting population decline.
Captive breeding programs allow for populations to increase in a controlled environment, free of the hazards found in the wild. The trick is not letting the critters you're raising become accustomed to humans. In the case of whooping cranes.

A human disguised as a whooping crane teaching actual
whooping cranes raised in captivity how to be cranes
(Reedsburg Times)

Sometimes removing the entire species from the wild is necessary. This happened with California condors and black-footed ferrets, which have both since been reintroduced to the wild, and mountain caribou and red wolves, which are nearly all currently in captivity while populations recover.
Mountain caribou were rounded up last year and placed in a great outdoor holding own where they are safe from wolf attacks. Red wolves have been reintroduced a few times, but those populations failed to survive. The majority of them are living in captivity while biologists figure out what went wrong.

Red wolf (https://www.fws.gov/southeast/wildlife/mammals/red-wolf/)

Another method is translocation, where members of one population are moved to another location to establish a population there. This usually happens to reintroduce reintroduce a species to an area where it has been wiped out. Wolves at Yellowstone, and a current project bringing fishers back to the Cascades, are two examples.
Once you've started on the path to recovery, monitoring is necessary to make sure targets are being met. Is habitat adequate? Are populations increasing? If not, what needs to be done to ensure success?
Many species have been listed as threatened or endangered for decades, leading some people to believe that the Endangered Species Act doesn't work. However, populations don't increase overnight, especially to a sustainable level.  Several species have been delisted, so while recovery is a long and winding road, in the end it has proven to be successful for the most part.
This week's information comes from USFWS, another USFWS page, and the Reedsburg Times of Wisconsin.