“Nostalgia for the good old days when everything was abundant is almost universal among conservationists…We lament the lost thunder of galloping buffalo, the sky-darkening clouds of pigeons and waterfowl, the flowing sea of the prairies, the velvet silence of the virgin woods…There are two possible explanations. Appreciation may have been enhanced by the intervening gains in education, or we may be incapable of appreciating anything until it has grown scarce.”
— Aldo Leopold, “Scarcity Values in Conservation” (1946)
Shakespeare provided us with the cautionary tale of Romeo and Juliet. Romeo mistakenly thought the unconscious Juliet was dead and abandoned hope, with tragic consequences. By analogy, if a species is mistakenly declared extinct, conservationists may give up on it. If the species, in fact, still survives, that could have tragic consequences that hasten the species’ eventual demise, such as no longer protecting its critical habitat.
So, how do we decide if a species is really extinct? The International Union for the Conservation of Nature (IUCN) manages the global Red List and provides the most definitive criteria: “Extinct” means there is no reasonable doubt that the last individual has died. “Presumed Extinct” means exhaustive surveys in known and/or expected habitat, at appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to record an individual. By that standard there was never any risk in declaring the Passenger Pigeon to be extinct since we knew to the hour when the last individual, Martha, died in her cage at the Cincinnati Zoo in 1914. But for most other species the death of the last individual goes undocumented, so “presumed extinct” is the safer call.
Last September, after a 5-year review, the US Fish and Wildlife Service (USFWS) made a bureaucratic decision to declare 11 bird species currently listed as “endangered” in the US to be extinct and no longer requiring the legal status afforded by the Endangered Species Act. Here are the birds now presumed to be lost:
But just as Juliet’s demise was premature, some birds that have been widely regarded as extinct are rediscovered, often long after their presumed demise.
To learn more about the author, Stanley Temple, click here.Curious about the Leopold-Pine Island Important Bird Area? Learn more here.