The first in-person meeting of the EMIGRA research team took place last week at Biosphere 2. The project aims to quantify the benefits provided by three species – Mexican free-tailed bats, monarch butterflies, and pintail ducks – and use the information gleaned to guide future species-specific conservation efforts for animals whose migratory ranges cross international boundaries.
Just as the sun is beginning to set at Carlsbad Caverns National Park in New Mexico, a bevy of tourists gather in an amphitheater in front of the cave’s natural entrance to witness a spectacle unique to just a handful of locations in the southwestern United States.
Almost every evening between the months of May and October, hundreds of thousands of Mexican free-tailed bats – most of them female – leave the comfort and safety of their roosts within the cave to dine on high-caloric nocturnal insects. It’s a nightly feast that is not only crucial to the survival of the individual animals, but that also ensures the survival of the population at large by supporting the nutritional demands of birth and lactation that are hallmarks of the season for the flying mammals.
The result is breathtaking. A seemingly endless stream of bats exits the mouth of the cave together, forming a sort of living cloud that spirals counterclockwise before it ultimately disintegrates on the horizon. At Carlsbad National Park, they’ve given this experience a name. It’s called the “Bat Flight Program” and, each night, it can take several hours for the show to end.
Many of the Park’s tourists in late summer and early autumn come to Carlsbad specifically to see the bats. In fact, the value of ecotourism associated with Mexican free-tailed bats – a phenomenon that is more or less limited to the United States – has been valued at $6 million per year. And, though it may not seem obvious on the surface, that’s a price tag that may be subsidized by rural and Indigenous communities in Mexico.
A research project led by Udall Center Associate Research Professor of Environmental Policy and Professor at the UArizona School of Natural Resources and the Environment Laura Lopez-Hoffman is looking to not only quantify the value of certain migratory species in terms of the “ecosystem services” they provide to human beings across their migratory ranges, but to ensure that the costs associated with protecting those species aren’t disproportionately shouldered by communities that won’t reap the lion’s share of the benefits those species provide.
The project is called “Especies Migratorias y Gobernanza de sus Ambientes” – shortened to EMIGRA – which translates to “Equitable Governance of Migratory Species and their Habitats.” It examines three migratory species – Mexican free-tailed bats, monarch butterflies, and pintail ducks – in an effort to examine the so-called “telecoupling” effect through the lens of “spatial subsidies.”
“Telecoupling” refers to an impact experienced on one area as a result of something that happens far away; “spatial subsidies” are a means of quantifying the degree to which habitat in one location subsidizes the benefits provided to humans by a species (i.e., “ecosystem services”) in another location.
So, rather than studying each species in a portion of its migratory range, EMIGRA’s team of roughly 20 international researchers and 20 undergraduate research assistants is trying to understand how environmental change at any point along each species’ migratory routes might affect human well-being elsewhere.
For instance, Mexican free-tailed bats provide a “cultural service” to tourists in the southwestern United States who are willing to pay to see the animals in their natural habitat. They also provide a “regulating service” for the agricultural producers near roosting sites who benefit from a reduction in pests consumed by hungry bats and, subsequently, a reduction in the amount of pesticides needed to protect their crops – a benefit that itself has been valued at about $12.4 million annually in Texas and New Mexico alone.
Contrast the value of those benefits with the costs associated with providing over-wintering habitat for the bats in central and southern Mexico – a concession that does not produce an economic benefit to the people in the region – and you’re looking at a roughly $9.7 million-dollar subsidy provided by Mexico to support ecotourism and agriculture north of the national border.
Jonathan Derbridge is a Research Scientist at the University of Arizona’s School of Natural Resources and the Environment. He is also the research director for the López-Hoffman Lab and an investigator for the EMIGRA project.
According to Derbridge, when looking to develop equitable conservation policies to support migratory species – especially species that migrate across governing jurisdictions such as international borders – it’s important to consider the species’ entire range.
“This abstract human idea of borders doesn’t really fit in the natural world,” says Derbridge. “So, if we really care about wildlife populations and the things they provide humans…we need to have policies that actually take account of that,” he says.
Where work conducted through the team’s previous NSF grant built on the telecoupling concept to develop the spatial subsidies approach, Derbridge says that the next phase of the EMIGRA project “is going much more into the broad social science (and) figuring out the governance system questions.”
This will involve going out into the field to speak with stakeholders about their interactions with migratory species and the governance involved with protecting those species. “What we’re really interested in finding is what factors have led to the state of governance that’s in place right now,” Derbridge explains, “because what we want to do ultimately is find our way to proposing really current ideas of governance which actually recognize that species that cross boundaries need transboundary conservation and policy.”
But, before that next round of work on the social-science side of the equation begins, the EMIGRA team first plans to drastically expand its list of target species.
Now that they’ve managed to demonstrate the spatial subsidies approach to examining the value of ecosystem benefits provided by their three species of focus, the goal is to expand that list to other species of interest.
In service of that goal, EMIGRA’s undergraduate research team from the University of Arizona, Brandeis University, and Mount St. Vincent University in Nova Scotia, Canada has been combing through a list of roughly 1000 North American migratory species since May 2022 in an effort to find a few dozen that have been studied in enough depth to provide the team with the information they need to start analyzing the ecosystem benefits they provide, as well as the potential telecoupling relationships of those species.
Finalizing that list was on the itinerary for the team’s week-long, in-person meeting at Biosphere 2 last week. Other items on the agenda included a professional science communication workshop for the undergraduate researchers and communications training for the entire team to help them get the word out about their work in a way that resonates with the general population.
But, perhaps even more important than the items they managed to check off their to-do list during the gathering is what Derbridge calls the “intellectual synergy” of being able to work together in the same place. “We are a social species,” says Derbridge. “We didn’t gather for the point of socializing, but the benefits of socializing while we talk about work are great.”