Chasing saltmarsh sparrows
Jumping across channels and squishing through mud at Rachel Carson National Wildlife Refuge, we advanced. Spread in a long arc, we all stepped forward in a circle, walking deliberately towards a series of mist nets stretched across the marsh. Someone began to clap.
A flash of movement drew our attention to the channel. A small brown bird fluttered out of the grasses and darted away across the marsh. We clapped louder, pushing it towards the net. Running forward, we herded the small bird closer until at last it encountered the woven fabric of the net. A member of the banding crew rushed to remove it, gently detangling the fine holes of the net from around the sparrow. The bird was placed in a soft drawstring pouch and carried to our banding station: a yoga mat in the shade of an umbrella strewn with measuring devices, pliers, and tiny metal bands.
Bri Benvenuti, a graduate student at the University of New Hampshire, carefully removed the bird from the pouch. There were no bands on the birds’ legs. This was one Bri and her colleagues had not caught before. It was quickly fitted with a uniquely numbered metal band on its left leg and a plastic red band on its right leg. Bri’s analysis was quick and methodical, collecting data on the bird’s size and health and calling out her findings to Dr. Adrienne Kovach, her advisor and data-recorder. Since the rest of us were not trained to handle it, we watched quietly, squatting in the grass as Bri explained what was so special about these birds.
Saltmarsh sparrows are elusive, bold-faced birds that barely sing to define themselves. Their entire lives are spent within the confines of salt marsh grasses and on the schedule of the tides. They nest in rapid cycles, trying to fledge their nestlings between high tides associated with the new moon. The nestlings grow quickly and are capable of flight 15 days after hatching. This leaves Bri a very short window to examine nests and gather data on breeding success for her thesis.
Bri works with the Saltmarsh Habitat & Avian Research Program (SHARP), a collaborative effort between governmental, academic, and non-profit organizations to advise management options for the conservation of birds like the Saltmarsh Sparrow that rely on tidal salt marshes for habitat. USFWS has provided much of the funding for SHARP, either from State Wildlife Grants or Hurricane Sandy funds. The first modern surveys for this species occurred as part of a partnership with USFWS, U. of Maine, the refuge, and the Maine Department of Inland Fisheries and Wildlife in 1997.
Between sea-level rise and the loss and degradation of habitat, these birds are vulnerable. For her thesis, Bri is investigating the sparrow’s nesting adaptations as well as testing the effectiveness of floating habitat islands for providing flood-free nesting habitat in the face of sea-level rise.
Bri was very excited to catch this bird, a fledgling, in her mist nets. This means a new generation of chicks successfully beat the double handicap of short breeding periods and climate change to fly safely across the patches of salt marsh they call home. Hopefully, the band Bri attached to this nestling will be one she reads next season as well. She gently removed her hands from around the bird and it dashed away, flying back to the obscurity of the channel.