In the 1940s you could have counted every Hawaiian stilt alive and stopped at about 200 [2].
Decades of hunting, the draining of wetlands for agriculture and development, and predators that arrived with people had taken a bird once abundant across the islands down to a number a person could hold in their head.
On July 20 the US Fish and Wildlife Service published a final rule moving the ae'o from endangered to threatened, effective August 19 [1].
The number underneath the decision is 1,511 - the five-year minimum average abundance for 2016 through 2023, drawn from the biannual waterbird counts the Hawaii Department of Land and Natural Resources has run for forty years [1].
The population generally sits between 1,500 and 2,000.
Here is the detail that makes this a recovery rather than a rounding error: the statewide carrying-capacity estimate is about 1,500 birds [1].
The ae'o is not merely up from its low. It is at roughly what the remaining wetlands can hold.
The Service's finding is careful, and worth quoting as written. The Hawaiian stilt 'is no longer in danger of extinction throughout all or a significant portion of its range but is likely to become so within the foreseeable future' [1].
That second clause is why the bird is threatened rather than delisted. It is honest. The recovery is real, and it is held in place by work that has to continue.
The 4(d) rule published alongside is the practical half. It permits take for conservation activities - predator control, habitat management - and lets authorised agency employees aid an injured bird or handle a dead one [1].
Rules like that exist because a change in listing status can accidentally outlaw the very work that produced the change. Somebody thought about that.
Forty years of counting birds twice a year, in wetlands, by people whose names are not in the rule.
That is what a recovery looks like from the inside.
