indicator

Shorebirds: Saltmarsh Sparrows

Adult saltmarsh sparrow at the Barn Island Wildlife Management Area in Stonington, Connecticut. Handling of all wildlife was done with approval through appropriate, federal and state permits and site permissions. Credit: Sam Apgar

Focus Question

Are Long Island Sound beaches and marshes supporting the shorebirds that depend on them?

Answer: The Partnership is making progress toward improving beach and marsh health so these habitats can sustain shorebird populations. Shorebird nesting sites are disrupted by predators, human disturbances, and tidal flooding. The Partnership’s work to conserve critical habitat and educate the public on protecting these birds has contributed to the least tern population becoming more stable, and the piping plover population increasing. The saltmarsh sparrow is gaining attention as a species who would benefit from habitat restoration efforts.

What Was Measured

Counts; Saltmarsh Sparrow is from University of Connecticut (Dr. Elphick’s Lab), Connecticut Department of Environmental Conservation’s Wildlife Division, and US Fish and Wildlife Service.

Status and Trends

Poor

Uncertain

Shorebird populations can indicate if the Partnership is making progress to achieve the Coastal Habitat Objective of protecting, enhancing, and assessing the extent and health of coastal habitats and their associated wildlife.

The health of least terns, piping plovers, and saltmarsh sparrows gives insight on the health of their habitats – are there healthy beach and marsh habitats? Do the habitats have food for shorebirds, like fish, worms, and other small creatures? These birds help tell the story of how healthy and vibrant Long Island Sound’s beaches and marshes are, and what other threats Long Island Sound’s wildlife face.

Saltmarsh sparrow numbers have declined considerably since the 1990s, but the population size has stabilized over the period from 2011 to 2022 (Gigliotti et al. 2025). Interpreting this stabilization is complicated because it was predicted by population models, which also predicted a continuation of the long-term decline would follow the stabilization (Field et al. 2017). It is possible that the stabilization arose simply because the multi-decadal cycles that determine peak tide heights have been favorable over the last decade and have dampened down the adverse effects of sea-level rise. If this is the case, then we should expect a return to a declining trend over the next decade.

Considerable work has been implemented to restore high-elevation saltmarsh habitat, which provides critical nesting sites for saltmarsh sparrows. This work has happened too recently, and over too small a proportion of Connecticut’s marshes, to account for the improvements seen in the saltmarsh sparrow’s population trend. Nonetheless, initial studies suggest that this work may be providing benefits (Gigliotti 2026), and expansion of these efforts has potential to mitigate the predicted future losses.

Data Notes

The New York dataset for this indicator includes monitored sites on the North Shore of Long Island (Long Island Sound) and additional sites in Peconic Bay and Shelter Island in the North Fork of Long Island (outside of the Long Island Sound watershed). Long Island Sound Partnership assesses this entire sub-region of Long Island for the least tern indicator because the birds frequently re-nest and might move from a Peconic Bay or Shelter Island beach to a Long Island Sound beach and back over the course of a year. The Partnership also maintains the same dataset for its other beach-nesting indicator, piping plovers.
New York data from 1990 to 2001 is currently not available.
Due to restrictions related to Covid-19, surveys were limited in 2020.

Sources

Field, CR, T Bayard, C Gjerdrum, JM Hill, S Meiman, and CS Elphick. 2017. High-resolution tide projections reveal extinction threshold in response to sea-level rise. Global Change Biology 35:2058-2070.
Gigliotti, FN, WA Beisler, JB Cohen, M Conway, MD Correll, AI Kovach, BJ Olsen, KJ Ruskin, WG Shriver, EL Tymkiw, and CS Elphick. 2025. Importance of phenomena expected to modify population trends of a threatened saltmarsh breeding bird community. Conservation Biology e70139.
Gigliotti FN. 2026. Population status and implications of salt marsh restoration for a threatened breeding bird community. PhD Dissertation, University of Connecticut, Storrs, CT.