Not everyone, however, is quite ready to pronounce the missing butterflies dead — at least not yet.
The Fish and Wildlife Service, which received Minno’s extinction recommendations late last year, is pondering its next steps.
Butterflies in the past have vanished for years only to make surprise reappearances. The Miami blue, for instance, was considered unofficially extinct after Hurricane Andrew in 1992 until the discovery of a colony of 50 in Bahia Honda State Park seven years later. Those disappeared in 2001 but more were later found in the Marquesas.
The Meske’s also once before went missing for a decade, Salvato said. “It’s a very indistinct butterfly. It’s not hard to overlook.’’
Daniels agreed it’s too soon to make a pronouncement. Many of the butterflies have brief life spans and live in areas difficult to fully survey. “That’s the inherent challenge, having enough data to verify that something is gone,’’ he said.
The service’s Warren said the butterflies Minno believes are gone also fall in a bureaucratic “gray area.” None of them were yet in the official pipeline for listing. Only two, the Schaus and Miami blue, have endangered status. Two others, the Florida leafwing and Bartram’s scrub-hairstreak, have been elevated to “candidates.” The agency won’t add something just to turn around and stamp it extinct.
“There is no requirement for us to do anything as far as a formal announcement that it’s gone,’’ Warren said. “At this point, I would say the smart thing for us is to take the recommendation under consideration and give it a little time to see what happens.’’
Minno argues something is wrong when butterflies vanish before the agency charged with protecting them even begins its process of declaring them in trouble. Environmental groups have expressed similar frustrations. In 2011, the Arizona-based Center of Biological Diversity sued the Fish and Wildlife Service over a backlog of 757 species awaiting listing.
Federal wildlife managers blame the sluggish action on shortages of money and resources, estimating the cost at simply listing a species as endangered or threatened at $150,000 to $300,000. In many states, there also has been strong political resistance to additional listings from landowners and developers.
Minno is persuaded the Zestos and Meske’s skippers are gone forever. His survey was supposed to take two years, he said, but he spent six on it, logging thousands of hours in the field. Other experts also did the same. No one has spotted any of them, in any stage of life, from larvae to butterfly.
“I thought I was going to find some at some point so I just took a lot more time,’’ Minno said. “They’re just not there.’’