New York Natural Heritage Program
Gull-billed Tern
Gelochelidon nilotica (Gmelin, 1789)

Habitat [-]
Historical habitat in New York is unclear due to lack of historical nesting descriptions in the state. Bent (1921) called this species the "marsh tern" because it nested along marshes and fed over them (Molina et al. 2009). However, most colonies along both the Atlantic and Gulf coasts nest on sandy beaches, barrier islands, or dredge spoils and often occur near ocean inlets (Portnoy 1977, Chaney et al. 1978, Schreiber and Schreiber 1978, Parnell and Soots 1979, Molina et al. 2009). In New York, Gull-billed Tern nests have been found on dredge spoil islands within bays and marshes and on barrier beaches (McGowan and Corwin 2008). The one barrier beach location previously known from New York has been abandoned and all currently known breeding locations are on bay islands consisting of marsh.

Associated Ecological Communities [-]
  • Brackish interdunal swales
    Temporarily tidally flooded temperate marshes in interdunal swales dominated by salt-tolerant graminoids. Individual swales occur as small patches positioned between fore-, primary and secondary dunes in a maritime dunes system, typically on barrier islands.
  • High salt marsh
    A coastal marsh community that occurs in sheltered areas of the seacoast, in a zone extending from mean high tide up to the limit of spring tides. It is periodically flooded by spring tides and flood tides. High salt marshes typically consist of a mosaic of patches that are mostly dominated by a single graminoid species.
  • Low salt marsh
    A coastal marsh community that occurs in sheltered areas of the seacoast, in a zone extending from mean high tide down to mean sea level or to about 2 m (6 ft) below mean high tide. It is regularly flooded by semidiurnal tides. The mean tidal range of low salt marshes on Long Island is about 80 cm, and they often form in basins with a depth of 1.6 m or greater.
  • Maritime beach*
    A community with extremely sparse vegetation that occurs on unstable sand, gravel, or cobble ocean shores above mean high tide, where the shore is modified by storm waves and wind erosion.

    * probable association but not confirmed
  • Maritime dunes*
    A community dominated by grasses and low shrubs that occurs on active and stabilized dunes along the Atlantic coast. The composition and structure of the vegetation is variable depending on stability of the dunes, amounts of sand deposition and erosion, and distance from the ocean.

    * probable association but not confirmed
  • Salt panne
    A shallow depression in a salt marsh where the marsh is poorly drained. Pannes occur in both low and high salt marshes. Pannes in low salt marshes usually lack vegetation, and the substrate is a soft, silty mud. Pannes in a high salt marsh are irregularly flooded by spring tides or flood tides, but the water does not drain into tidal creeks. After a panne has been flooded the standing water evaporates and the salinity of the soil water is raised well above the salinity of sea-water.

Associated Species [-]
  • Black Skimmer (Rynchops niger)
  • Caspian Tern (Sterna caspia)
  • Common Tern (Sterna hirundo)