Sometimes Goodbye is a Second Chance… for Research
With the bright blue upper surface of their wings back in sight, researchers like Erica Henry are taking advantage of their second chance with the Miami blue butterfly. Henry first started studying rare butterflies 12 years ago. Today, she’s a postdoctoral researcher at North Carolina State University.
Her preliminary research about the Miami blue focused on finding suitable ways to count and estimate the butterfly’s population numbers. But the better she became at counting them, the sooner she recognized a pattern: Rainfall seems to affect the Miami blue’s reproductive cycle.
When clouds over the Key West National Wildlife Refuge get dark and the water no longer reflects blue skies, the rain that descends upon the islands fuels plant growth. In turn, this spurs a greener habitat, Henry said, revitalizing the plants Miami blue caterpillars depend on.
“So, the pattern is that it will rain a bunch, and then there’s a little bit of a lag — there’s a little bit of time after that rain where you don’t see a whole lot of adult butterflies,” she said. “And then we get this flush of butterflies.”
Postdoctoral researcher Erica Henry grins at the camera during a Miami blue populations assessment. (Photo courtesy Erica Henry)
But even when there are spurts of higher butterfly densities, this population has nowhere to go — and even if it did, the Miami blue’s half-inch wings can’t support a long journey. That’s why Steele Cabrera said it’s important to establish several populations in different habitat patches to bolster what researchers call a “metapopulation.”
She likened a metapopulation to several dots on a map, where each dot is its own Miami blue population in a different location. If they’re close enough, some butterflies might be able to travel between dots occasionally. This connection allows each individual population to be strengthened by the numbers in their surrounding communities.
“What can happen when you have a good, healthy metapopulation system is that if, say, something happened to one of those populations, one of those dots on the map… well, butterflies from those other populations can come in and recolonize that area,” she said.
Right now, there’s only one dot, Steele Cabrera said: the Key West National Wildlife Refuge. Without a metapopulation to reinforce it, that dot could be wiped from the map from just one cold snap, drought or massive hurricane. And that’s why she said the ultimate goal of her research is to cultivate more supporting populations and available habitat for this species by reintroducing adult butterflies into the wild.
Researchers from the Daniels Lab prepare adult butterfly specimen for reintroduction into the wild. (Photo courtesy Geena M. Hill)
These reintroduction efforts don’t start when the tiny creatures get released; they start in the lab. Like the age-old school projects where a child would raise a monarch from egg to caterpillar to pupae to butterfly, it’s a similar process for staff in the Daniels Lab within the McGuire Center for Lepidoptera & Biodiversity, where Steele Cabrera has worked the last five years.
Except multiply that one caterpillar by a couple hundred or thousand.
“It’s very hard work that is constant. It’s like having hundreds or thousands of little pets that need daily care,” she said.
Using the adult butterflies they've nurtured, the Daniels Lab has already began reintroducing the Miami blue to alternate locations around the Keys, she said. One of their more successful reintroductions took place at Bahia Honda State Park, the very area the species was rediscovered while on the brink of extinction.
From being laid as an egg to “dying of butterfly old age,” the Miami blue lives for about a month. Steele Cabrera said that the reintroduced population in Bahia Honda persisted for at least five to six generations, or around six months, without researcher interference. Unfortunately, it didn’t survive the winter and dry seasons — but that long-term survival is the researchers’ ultimate goal.
“It’s not like Jurassic Park where life finds a way — you put them there, and they’ll be fine,” she said. “It’s a whole lot more complicated than that.”