In both name and appearance, Saltmarsh Sparrows evoke their palustrine home. The gray and orange on their face recall an early morning sun peeking over a marshy horizon, banishing an ashen pre-dawn. Emanating from that orange center, buff brightens a background of brown while black streaks shadow their way forward, retreating from the incoming daybreak.
Top Tips
- Locate likely habitat, with watercraft if possible
- Patiently watch and listen; be confident in the identification
- Provide comments and make an extra effort to Confirm breeding
Tightly bound to their chosen habitat, Saltmarsh Sparrows in Maryland are restricted to the southern Chesapeake coast. In the mid-20th century, they could be found on the Eastern Shore as far north as Kent Narrows and were uncommon breeders on the Western Shore north to Sandy Point and west to Cobb Island. However, their numbers have plummeted range-wide; since 1998, over 87% of their population has vanished. Extinction is a grave and genuine threat to this bird. Alongside this population decline has been a considerable range retraction. In BBA2, they were found in a single Western Shore block and only as far north as Dorchester County on the Eastern Shore.
Saltmarsh Sparrow breeding distribution map from the Maryland & DC Breeding Bird Atlas 2 (2002–2006) and Atlas 3 (2020–2022). Green fill indicates a BBA2 Saltmarsh Sparrow breeding observation in that block, while black dots represent coded BBA3 observations.
Habitat
Saltmarsh Sparrows breed in elevated portions of saltmarsh (measured on a scale of inches) known as “high marsh” that are typically only flooded infrequently. The sparrows prefer nesting in high marsh vegetation that is taller and denser, preferably with a robust thatch layer. This microhabitat often occurs near edges or water. High marsh tends to have a vegetation community composed of saltmeadow cordgrass (Sporobolus pumilus) as well as saltgrass (Distichlis spicata), saltmarsh rush (Juncus gerardii), and black needlerush (J. roemerianus). Low marsh, which sits below the mean high-water level, is typified by smooth cordgrass (Sporobolus alterniflorus).
Saltmeadow and smooth cordgrass can be differentiated by height and by their flowering spikes. Smooth cordgrass grows 3–6 feet tall and has spikes that stand erect at the top of the stem while saltmeadow cordgrass grows 2–2.5 feet tall and has spikes that angle out from the stem.
Identification
Confidently identifying Saltmarsh Sparrows sometimes requires patience, as views can be brief and distant. Look for an orange triangle on their face that contrasts with a buffy breast. Black streaks cover the breast and sides, and, with a close view, fine black markings can be seen in the post-ocular orange streak. Seaside Sparrows are regularly found nearby, but are darker, larger-billed, and have yellow rather than orange on their face. Nelson’s Sparrows are quite similar; they were considered the same species as Saltmarsh Sparrow until 1995 (Sharp-tailed Sparrow) and the two will even hybridize. Nelson’s have less contrast between face and breast and largely lack any post-ocular streaking—and are essentially absent from Maryland during the breeding season.
Behavior and Phenology
Saltmarsh Sparrows have a fascinating and unusual breeding strategy. They are promiscuous, meaning they do not form pair bonds. The males do not defend territories or help with any part of the breeding process beyond copulation. Males search for females throughout the breeding season and appear to forcibly copulate with the females they find, but there’s no evidence that any sperm is transferred during these aggressive interactions. Instead, it is hypothesized that these are ritualized copulations that allow females to assess male dominance, and females then use these cues to solicit copulations from dominant males.
Saltmarsh Sparrows begin nesting one to three weeks after their return to Maryland in late April or early May. Their nesting season is often protracted because flooding from “spring” tides—higher than normal tides that occur twice a month—can cause nest failure and force the birds to renest. Eggs have been recorded in Maryland nests from May 14 to August 21. The female lays 3–6 eggs in a simple cup woven from dried grass stems, then incubates the full clutch for twelve days. The young fledge at ten days, although by five days they can crawl out of the nest to escape flooding. The female continues to feed her fledglings for another two to three weeks before they reach independence.
Breeding Codes
Saltmarsh Sparrows are somewhat hard to detect and don’t have many of the breeding behaviors other songbirds have. Females carrying food is probably the best way to confirm them, but their low reproductive productivity makes confirmations a challenge.
Habitat. Their breeding habitat is very specific, so code H (habitat) is straightforward to apply.
Singing. Their song is quiet, but singing (S and S7) may continue quite late in the year. Code M (multiple males singing) should not be used without considerable support, given this species’ dwindling population.
Pairs. No pairs are formed, so this code should not be used for Saltmarsh Sparrows.
Territorial. No territories are maintained, and intraspecific aggression appears to be courtship-oriented.
Courtship. Males aggressively attempt to mount females who resist equally aggressively, apparently as a form of courtship. Flight songs are also given as part of the courtship ritual.
Agitation. Females may chase away males that get too close to their nest and will chip repeatedly if intruders are too close.
Distraction Display. Saltmarsh Sparrows do not perform distraction displays.
Maryland is home to a quarter of the global breeding Saltmarsh Sparrow population—more than anywhere but New Jersey—and Maryland will play a critical role in conserving this species. To read more about the details of the conservation strategy in Maryland, go to page 101 of the Atlantic Coast Joint Venture’s Saltmarsh Sparrow conservation plan. Maryland has designated Saltmarsh Sparrows as a Species of Greatest Conservation Need, and they are a priority species for the Atlas. Any observations should be accompanied by comments and additional effort to Confirm breeding. If possible, watercraft should be used to access habitat away from roads; canoes were successfully used in BBA1 to search for breeding evidence.
References
Greenlaw, J.S. C.S. Elphick, W. Post, and J.D. Rising. 2020. Saltmarsh Sparrow (Ammospiza caudacta), version 1.0. In Birds of the World (P.G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.sstspa.01
Robbins, C.S. 1996. Atlas of the Breeding Birds of Maryland and the District of Columbia. University of Pittsburgh Press. Pittsburgh. 479 p.
Stewart, R.E. and C.S. Robbins. 1958. Birds of Maryland and the District of Columbia. United States Government Printing Office, Washington, DC.