Sparrows' Backpacks Help Tell a Salt Marsh's Story
Scientists track the solar-powered transmitters carried by the birds to learn about the health of salt marshes at risk of rising sea levels.
"It's surprising how much overlap there is between crafts and bird science," says Dr. Talia Kuras as she uses a small crochet hook to loop a fishing line loop around a salt marsh sparrow's body and over its leg. Talia is one of the researchers fitting salt marsh sparrows at Lubberland Creek Preserve with tiny, solar-powered transmitters attached to harnesses that resemble tiny backpacks. Why? First, some context.
The Lubberland Creek Preserve in Newmarket is one of two of the largest salt marshes on Great Bay, which itself is the second-largest inland estuary in North America. Salt marshes support estuarine plants and animals, as well as help shield shorelines from flooding. Salt marshes were also one of the first natural resources that colonial settlers tapped into upon their arrival in New England in the 1600’s, digging trenches to convert the marshes into agricultural land. You can still see these trenches at many marshlands across New England.
Salt marshes are used to getting wet—they naturally flood as the tides ebb and flow. But rising sea levels mean that the low marsh areas, which are usually just covered for a bit, are now staying underwater much longer—or even all the time. When the low marsh is flooded too often, it simply can’t survive. For the salt marsh and all its wild residents to hang on, these habitats need to be able to move, or “migrate,” upland to higher ground. Without space to shift, the low marsh could disappear, taking vital homes for birds like the salt marsh sparrow and other species with it.
Salt marsh sparrows nest exclusively in these landscapes, including Lubberland Creek Preserve, making it a prime location to study these enigmatic birds. Among many unique traits, female salt marsh sparrows build their nests just inches above the marsh to avoid predators, but this leaves them prone to flooding during full moon high tides. This risk means chicks must fledge quickly—within 10 to 12 days—making their nesting cycle a finely tuned adaptation to the marsh’s rhythms. Scientists estimate that at the current rate of sea level rise, salt marsh sparrows will be gone by 2050. This perilous position has given this already vulnerable bird the unenviable moniker of being a “living extinct” species.
Salt marsh sparrows are important indicators of marsh health—which is where the solar-powered backpacks come in. By tracking the birds’ movements, scientists can get the information they need to better protect and restore these threatened habitats.
Dr. Kuras and her crew of researchers fasten the solar-powered tags onto adult salt marsh sparrows (with the help of, you guessed it: crochet hooks) by hooking a “leg-loop harness” around their legs and over their wings, resting the pack along their backs where they won’t restrict movement. “This effort is part science, part arts and crafts project,” says Dr. Kuras. “We use jewelry string, crochet hooks, crimp beads, and super glue together with high-tech solar-powered radio tags. It’s a pretty clever and effective combination.” These crafty solar tag “backpacks” have tiny transmitters that ping a grid of receptors across Lubberland Creek’s salt marsh. “The grid pattern means we can get multiple nodes detecting each bird's location at each time stamp,” notes Dr. Kuras. “We can pinpoint each bird's location with a relatively high level of accuracy as a result.”
A saltmarsh sparrow is tagged with a tiny solar transmitter that allows scientists to track its movements throughout the Lubberland Creek Preserve in Newmarket, New Hampshire.
Thanks to Dr. Kuras’ research, The Nature Conservancy can use real, on-the-ground information from these tiny “backpacks” to make smart decisions about how we restore the marsh to help it and its wild residents. The data will help inform the kinds of restoration techniques—like how we manage water flow or where we plant new marsh grasses—that actually make a difference for the salt marsh sparrow and other species that need these habitats to survive.
But it doesn’t stop there. As the seasons pass and more data comes in, we’ll be able to see how the sparrows react to the changes we make. Are they nesting in new spots? Are chicks surviving better? Do the birds return year after year? By watching the sparrows and seeing how they adapt (or don’t) to our restoration work, we can keep adjusting our approach and give them the best possible shot at thriving—even as the world around them keeps changing.
The lessons learned here will also help inform salt marsh restoration efforts all along the East Coast. By restoring these tidal habitats, we’re doing more than protecting the vulnerable salt marsh sparrow—we’re strengthening our coastline and our communities against the growing threats of storms and flooding brought by climate change. In this way, what we learn from these solar-powered sparrows is helping to shape the future of the salt marsh, one tiny data point at a time.
A salt marsh sparrow, a mix of white and brown with a yellow/orange eye stripe, perches delicately on the fingertip of a researcher's hand.
Dive deeper into our coastal conservation efforts
Learn more about our coastal restoration efforts, including salt marsh restoration and oyster reef restoration.
We Can't Save Nature Without You!
Sign up to receive monthly news, updates and local events from New Hampshire.
Stories in New Hampshire
Lubberland Creek Preserve
Discover Great Bay’s wild side! From salt marsh to oak forest, this 400-acre preserve offers rich habitats and quiet trails for exploration.
The Freedom of Flow
One tiny creature spurs big change in reconnecting our rivers to the sea (and making travel safer for people too!)
What Happens at a New Hampshire Nature Preserve?
As countries race to protect at least 30% of Earth’s remaining intact ecosystems, see three ways local stewards manage New Hampshire's existing protected areas.