NEWTOWN, Conn.— The Center for Biological Diversity filed a formal petition today with the U.S. Fish and Wildlife Service seeking protection for the saltmarsh sparrow under the Endangered Species Act.

This is the only native bird species that breeds solely in the salt marshes of the Northeast. But rising sea levels, climate change and human development have destroyed much of the bird’s habitat along the eastern seaboard.

Saltmarsh sparrows are known for their whisper-like song and promiscuous mating behavior, with males and females breeding with multiple partners, frequently resulting in every egg in a nest having a different father.

“The fate of these frisky little songbirds is inextricably tied to our ability to protect the tidal marshes they call home,” said Stephanie Kurose, deputy director of government affairs at the Center for Biological Diversity. “Saltmarsh sparrows are creeping dangerously close to extinction and could disappear within the next 50 years. On this Earth Day, we’re asking the Fish and Wildlife Service to take immediate action to protect these beautiful marsh-dwelling birds.”

Saltmarsh sparrows spend their entire lives in the thin ribbon of coastal salt marshes along the Atlantic and Florida Gulf coasts. The sparrow has undergone steep declines in the last quarter century with more than four out of every five birds having disappeared since 1998 — an estimated population decline of 87%. The Fish and Wildlife Service identified the sparrow as needing protection in 2019, but has yet to take action.

Sea-level rise, as well as historic losses and degradation of salt marsh habitat, are the primary threats to the saltmarsh sparrow. High tides and storm surges are increasingly flooding sparrow nests and their high marsh habitat. When nests flood, chicks may drown or eggs may float away. Low reproductive success is the primary reason the saltmarsh sparrow population continues to drop.

Roads, buildings, beachside homes and other development have contributed to the loss of natural habitat that saltmarsh sparrows rely on to survive.

“It would be devastating to lose these sweet, soft-spoken birds I call neighbors,” said Kurose. “If the Service acts fast to protect the saltmarsh sparrow and its habitat, it can also help protect many other species that depend on our coastal wetlands for survival.”

The Fish and Wildlife Service has been reviewing the status of the saltmarsh sparrow since 2019. The agency previously said it would make a decision about whether to protect the sparrow by September 2023. It then delayed its decision again to September 2024. It is unknown whether the agency plans to meet its latest deadline.