SALTMARSH SPARROW ( caudacuta)

Photo: Saltmarsh sparrow, credit: Eric Lipton The saltmarsh sparrow is a tidal marsh obligate songbird of Conservation Concern that occurs exclusively in saltmarshes along the Atlantic and Gulf Coasts of the United States. Its breeding range extends from Maine to Virginia including portions of 10 states. Across its range, the saltmarsh sparrow is experiencing low reproductive success, due primarily to nest flooding and predation, resulting in rapid population declines. Although it has not been quantified, there is strong evidence for range contraction at both the northern and southern limits of the breeding range. Furthermore, breeding individuals are not evenly distributed across the entire range, with approximately 78 percent of the breeding population breeding in marshes of the Mid-Atlantic States. While the species still occupies the majority of its historical range, the number of individuals within the breeding range has significantly declined since 1998. Based on surveys in 2012 the population was estimated at 60,000 individuals, having declined at an average of 9 percent per year across the range since 1998. Projecting those declines through 2018, we estimate that current populations would be approximately 34,072 individuals. This represents a decline of 84 percent from the 212,000 individuals estimated in 1998. Numerous threats have been identified as impacting the saltmarsh sparrow and/or its habitat. These include: habitat loss, fragmentation, or degradation; climate change; hybridization; predation; contaminants; and other factors such as disease and altered food webs. However, the overwhelming principal threat is excessive tidal flooding and habitat change due to climate- driven . Tidal marshes across the Atlantic Coast are being lost or degraded at a rapid rate due to a combination of historic and on-going direct anthropogenic impacts (e.g., development, ditching, shoreline hardening, etc.) and the impacts of sea level rise. Range-wide loss and degradation of tidal marsh habitat has resulted in smaller, more fragmented habitat patches, as well as a disproportionate loss in suitable nesting habitat for the saltmarsh sparrow. Site-specific rates of habitat loss have been correlated with multiple localized factors, including nutrient input from agricultural and urban runoff, shoreline hardening, geomorphic setting, tidal range, and presence of invasive plants or . Although our understanding of how these variables interact, exacerbate, or ameliorate habitat loss is less understood, we have concluded that these factors do influence how resilient a marsh is or will be to the impacts of sea level rise.

LIFE HISTORY Saltmarsh sparrows forage in a range of marsh habitats but nest exclusively in the high marsh where flooding happens only during peak spring tides. Saltmarsh sparrow diet consists of insects, amphipods, and spiders during the breeding season. Nestlings feed only on insects. Immediately following the breeding season, the seeds of smooth cordgrass (Spartina alterniflora) are added to the diet. Their diet during winter is unknown, but is thought to consist mostly of seeds. Nesting typically occurs from May through early September. Saltmarsh sparrows breed from Maine to Virginia and winter from North Carolina to Florida. Hatching takes place 12 days after egg-laying concludes, and the entire nesting cycle from first egg to fledging is from between 23 and 27 days. Fledging can occur as early as 8 days after hatching. Records show that male saltmarsh sparrows live up to 10 years and females live up to 6 years. Individuals breed for the first time during the following summer after fledging. Saltmarsh sparrows exhibit high site fidelity to both their breeding and wintering habitats. Adults are non- territorial and the males and females do not practice mate fidelity. Females mate with multiple males and they are the sole nest builder and fledgling caregiver following mating. When nests fail due to flooding, predation, or other causes, females re-nest up to three times per breeding season. Nests are constructed in the high marsh where inundation occurs monthly during spring tides. They are placed just several inches above the marsh surface in saltmeadow cordgrass (), black rush (), or smooth cordgrass (S. alterniflora). Nests are typically situated under thatch, have woven grasses above the nest, or a combination of the two. Females time their egg-laying to the new moon when the high tides are at their lowest level and the flooding risk is lower. They typically lay four eggs and young sparrows hatch featherless and blind and require parental care. After 9 to 10 days, they are feathered, vision is enabled, and they are mobile. The fledglings apparently do not stay together after fledging and the females range up to 2.6 acres searching for food and then return to multiple locations to feed the young. Flooding is the main cause of nest failure. Nests that are constructed higher in the marsh are less susceptible to flooding but more vulnerable to predation. The woven grass or thatch canopy aids with egg retention during flooding and provides cover from predators. Successful nests tend to have more canopy cover than unsuccessful nests. Older hatchlings can survive flooding by climbing plant stalks or even remaining in the nest with their head above water if they are old enough to survive exposure to cold water. Suspected nest predators include snakes, ducks, wading , hawks, gulls, corvids (Corvus spp.), blackbirds, coyote (Canis latrans), raccoon (Procyon lotor), domestic cats, and rodents.

HABITAT Saltmarsh sparrows are habitat specialists that only live in the tidal saltmarshes of the Eastern Coast of the United States. Nesting occurs in the high marsh, where Spartina grasses dominate and create a low-statured meadow. Adults and fledglings forage in the low marsh and the fringes of channels and pannes. Adults seek cover on the upland edge in shrubs or common reed ( australis) during storm events and floods. In their wintering range, they are primarily found in Spartina marshes.

HABITAT RESTORATION RECOMMENDATIONS Ongoing tidal marsh restoration is focused on four primary strategies that are not mutually exclusive and depend on site-specific conditions. These consist of: protection and management of land where marsh migration can be allowed and/or facilitated; marsh restoration focused on building elevation; marsh restoration focused on restoring or improving hydrology; and removal of invasive species. In recent years, all of these strategies have been explored to varying extents in the Chesapeake Bay region. Anticipating how marshes will respond to targeted restoration actions will require an understanding of the primary stresses acting on the specific marsh. Having this understanding can also lead to the development of appropriate restoration strategies that are site specific. Priority Areas in Maryland and Delaware According to the Atlantic Coast Joint Venture’s Saltmarsh Sparrow Habitat Prioritization Tool SALS Prioritization Tool, priority nesting areas in the Chesapeake Bay portion of Maryland occur in the Nanticoke River mainstem tidal marshes, downstream of Marshyhope Creek, tidal marshes in and around Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area, the islands in Tangier Sound, and downstream portions of the major Tangier Sound tributaries, including the Wicomico River, Monie Bay, Manokin River, Big and Little Annemessex Rivers, and Pocomoke Sound. On the Atlantic Coast, the narrow band of tidal saltmarshes that ring Chincoteague Bay on the mainland and Assateague Island support significant populations of breeding saltmarsh sparrows. The Maryland breeding population occurs in coastal areas of four counties: Dorchester, Wicomico, Somerset, and Worcester. Priority breeding habitat in Delaware occurs primarily on the Delaware Bay and tidal tributaries from just below the Chesapeake and Delaware Canal almost to Cape Henlopen. Habitat Types and Target Plant Species Saltmarsh sparrows occur and nest exclusively in tidal saltmarsh. Nesting takes place in the high marsh, which is tidally inundated monthly and is dominated by saltmeadow cordgrass (S. patens) and saltgrass (Distichilis spicata). Foraging occurs in the low marsh, which is inundated daily and is dominated by S. alterniflora. During storms and flooding events adults seek shelter in shrubs such as marsh elder (Iva frutescens) and groundsel bush (Baccharis halmifolia) on the higher ground, as well Phragmites. Restoration Approaches Successful nests require a minimum of 23 days where the tides do not reach a height that causes nest failure. Researchers have found the saltmarsh sparrow is experiencing low reproductive success across its entire breeding range, due primarily to nest flooding and predation, resulting in rapid population declines. Species experts anticipate range contraction and population decline will continue due to sea level rise and the associated flooding and loss of suitable breeding habitat. The saltmarsh sparrow urgently requires more high quality breeding habitat, defined as high marsh areas (S. patens, D. spicata, J. gerardii) at sufficient elevation with acceptable flooding regimes and predation levels such that the sparrow can reproduce successfully. Protect additional land surrounding saltmarsh (fee or easement) One strategy for ensuring the saltmarsh sparrow has adequate habitat is to protect uplands and other areas adjacent to existing saltmarsh to allow for habitat migration and avoid negative effects related to development, such as increased freshwater runoff, nutrients, contaminants, and predation by domestic animals. Biologists anticipate these protection measures may help reduce predation and provide future management options for saltmarsh habitats. Habitat protection efforts should focus on areas that are projected to become saltmarsh in the future and prioritize parcels with the greatest conservation value. The Saltmarsh Sparrow Habitat Prioritization Tool can assist in identifying priority sites to focus this effort (SALS Prioritization Tool).

Phragmites control in the saltmarsh to upland transition zone Habitat management of existing saltmarshes will play an important role in the conservation of the saltmarsh sparrow. One measure to improve habitat is management of the transition zone (area lying between existing saltmarsh and upland habitats); especially those areas that are currently dominated by stands of invasive Phragmites, which cannot be used by saltmarsh sparrows for nesting. Reducing or eliminating Phragmites facilitates the establishment of native high marsh vegetation and increases use by breeding saltmarsh sparrows. Herbicide application followed by mowing is generally the most effective management approach. However, repeated treatments are often necessary if the underlying hydrologic impairments of the marsh are not also addressed. Ditch remediation/runnels/ditch plug removal Throughout the saltmarsh sparrow’s breeding range, saltmarsh habitats have been extensively manipulated for agricultural purposes and ditched for controlling mosquitoes. Restoration of natural hydrological regimes benefits the long-term health of saltmarshes. Although the benefits of hydrological restoration and the associated improvement of saltmarsh habitat has not been fully evaluated to assess impacts to the saltmarsh sparrow, experts believe there may be benefits to the species through improved habitat condition and reduced flooding of nests when restoration activities are appropriately designed. Some techniques, such as cutting/raking salt hay into ditches, are relatively inexpensive and require only labor. Others, such as filling ditches with sediment from the upland edge, can be expensive due to costs for labor, equipment, and materials. In Maryland and Delaware, extreme caution should be used when restoring ditched tidal marsh so that the impacts of sea level rise and land subsidence are not inadvertently exacerbated.

Install and actively manage self-regulated tide gates Throughout the saltmarsh sparrow’s breeding range, dikes, roadbeds, and other structures that include tidal restrictions that alter the exchange of seawater, such as culverts and narrow bridges, have impacted many saltmarsh habitats. Although most tidal restrictions can have a negative effect on tidal saltmarsh ecosystems, the complete removal of restrictions is not always possible when they are associated with existing infrastructure or provide other benefits, such as reducing inland flooding. Where possible, habitat managers should consider the installation of self- regulated tide gates, which are designed to close when the tide reaches a predetermined height. To meet multiple objectives, self-regulating tide gates can be managed to allow normal tidal flow throughout most of the year, be deployed to reduce nest flooding during the breeding season, and improve egg and chick survival. Additionally, managers should consider self- regulating tide gates at sites undergoing tidal restriction work (e.g., culvert and bridge replacements). Note: This would apply only for sites where we know nest flooding is a problem and infrastructure (e.g., berms, dikes, and other water control structures) can be modified. This approach will need to be highly targeted and balanced with a separate strategy of removing tidal restrictions to increase marsh resiliency. We do not recommend installing tide gates in natural, unrestricted systems that do not already have infrastructure in place. Self-regulated tide gates will need dedicated management and periodic maintenance to be functional.

Apply thin layer deposition (TLD) of sediment to increase overall marsh elevation This technique involves the addition of sediments to marsh sites to raise surface elevation and reduce flooding associated with sea level rise and marsh subsidence. When carefully designed and implemented (i.e., there is direct contractor oversight to ensure proper composition and amounts of material are applied), the establishment of high marsh habitat is possible. A nearby or known dredging site as a source of sediment is normally required. TLD has the potential to fail to create marsh, if done improperly. The level of effectiveness for saltmarsh sparrows is uncertain at this time. Although TLD has been used to raise marsh surface elevation, direct benefits to saltmarsh sparrow via creation of high marsh with the correct elevation for successful nesting have not been demonstrated. Research is ongoing.

Evaluate the potential for creating nesting microtopography/mounds Although untested, research managers should consider the application of small areas of sediment to provide higher elevation nesting areas that are less prone to flooding . Because this is not a proven technique for improving habitat and reproductive success, habitat managers should work closely with researchers to design experimental studies for testing approaches for creating and determining the effectiveness of microtopography in an adaptive management framework.

Evaluate predator management to improve nesting productivity Nest predation is known to be a limiting factor in parts of the saltmarsh sparrow breeding range. If predation appears to be limiting breeding success, managers should identify the nest predator community and develop effective predator control measures. Furthermore, managers should employ the principles of adaptive management to evaluate improvements in saltmarsh sparrow nest success to inform future management actions. It is unclear at this time whether predation is playing a major role in decreasing breeding success in Maryland and Delaware.

LITERATURE CITED

Curson, D. 2020. Personal communication with Audubon MD/DC Biologist.

U.S. Fish and Wildlife Service. 2019. Report on the current conditions for the saltmarsh sparrow. May 2019. U.S. Fish and Wildlife Service, Northeast Region, Charlestown, RI, 107 pp.