If you spend any time around saltmarshes here on the Cape, there’s a special but underappreciated bird I bet you haven’t noticed. For one thing, it’s a sparrow – the birds everybody loves to ignore. They’re “little brown jobs”, too hard to identify, not pretty enough – they’ve heard it all, but they haven’t let it get them down. But one mighty force is starting to get to this particular sparrow, and it’s the reason they are the latest addition to the Massachusetts endangered species list. It’s the Saltmarsh Sparrow, and that bully climate change has them on the ropes.
If you have a dusty, old bird book, you might see the Sharp-tailed Sparrow in there – that was before they split this species from the very similar but weirdly complicated Nelson’s Sparrow that breeds both in coastal Maine and interior freshwater marshes in places like Manitoba. Figure that one out. Saltmarsh Sparrows are actually pretty handsome if you get a good look with bright ochre faces and breasts in fall and winter, fading paler by summer. But getting a good look is ambitious – they are small, furtive, and, they’re quiet singers. While most male songbirds sing from the diaphragm, Broadway-style, these guys sing like they’re in a restaurant whispering something gossipy about someone at the next table.
They breed from Maine to Maryland and winter from Cape Cod to Cape Canaveral. Whatever the time of year, if you want to see one, you need to be in a saltmarsh. Saltmarsh Sparrows are inextricably tied to that thin ribbon of saltmarsh hugging the east coast - they literally can’t live anywhere else. In ornithology-speak, they’re an obligate saltmarsh specialist. And if one thing is true in species conservation, it’s that you don’t want to be a specialist. Generalists like Song Sparrows and chickadees are not picky about where they nest or what they eat, so they are common and secure. Specialists are picky, so they end up on endangered species lists.
Saltmarsh Sparrows aren’t just picky, in that they only nest in saltmarshes, they’re also compulsive gamblers – every nest is a sketchy, all-or-nothing bet on the tides. If they’re lucky, they build their nest and fledge their chicks between the biggest flood tides. In unlucky years, thanks to sea level rise and increased storm activity, entire marsh systems may not fledge any chicks at all. Plus, to add another vice to their portfolio, they’re swingers – mating is promiscuous and most broods of chicks will be of mixed paternity.
Saltmarsh Sparrows are well studied, with a number of both long and short-term studies across their range documenting their breeding success. And the scientists who know them best say the species has declined 75% since the 1990s, and project that they could be extinct by mid-century. Like with Piping Plovers, Massachusetts hosts a significant chunk of the global breeding population of this species, so we have a chance to help these guys by really focusing on saltmarsh conservation, as if there weren’t already a thousand other reasons to do so.
But for now, they are still relatively common around here in most good-sized tidal marshes. So next time you’re in a saltmarsh, try to ignore that obnoxious Willet screaming at you because you’re too close to the chicks, and try to tune your ear to that far-away, whispery song of the swinger of the saltmarsh, the Saltmarsh Sparrow.