Black Skimmer
New York Status: Special Concern
Federal Status: Not Listed
Management Plan
The Black Skimmer Conservation Management Plan (PDF) provides a full ecological perspective covering the major issues influencing successful breeding in the state. The overarching goal is to maintain a self-sustaining population that is secure in perpetuity. This can be ensured by maintaining a five year annual mean minimum number of ten (10) colonies and a five year annual mean minimum population of 550 breeding pairs.
Description
Black skimmers are a medium-sized, sexually-dimorphic species with size differences between males and females easily noticeable. Adults range in size from approximately 15.5-19.5 inches in length with a wingspan of approximately 14-15 inches. Adult skimmers weigh between 8-12.8 ounces. Black skimmers are easily identifiable with predominant black markings on the top half of their bodies and white below. Skimmers have bright reddish orange colored webbed feet. Juvenile skimmers by contrast are mottled brown and black on top and off-white underneath.
Perhaps the most noticeable feature of the black skimmer is its uniquely shaped bill. The skimmer bill is approximately 2-2.5 inches long with the lower mandible obviously longer than the upper, often by as much as an inch. However, during early juvenile development both upper and lower mandibles are the same length. Colored bright reddish orange at the base and black at the tip, the bill is compressed laterally and is reminiscent of a knife blade. This unique feature of black skimmer is an evolutionary adaptation to its feeding and foraging behavior. Black skimmer calls are often described as a bark.
Life History
Black skimmers are a migratory species. During the early spring black skimmers leave their southern wintering habitat and begin to migrate northward along the eastern coast. Black skimmer arrival in New York State begins during the last week of April and into early May. After nesting and breeding during the summer months, juveniles and adults will often stay and loaf along New York's coast into the fall. Migration back to wintering grounds usually occurs during October and into November however, skimmer have been known to stay in New York as late as December.
Black skimmers prefer to nest upon beaches, salt marsh islands, dredge spoil islands, and sand bars and nest primarily along the southern coast of Long Island. Black skimmer nests are simply a small scrape or depression on the beach or within a wrack deposit. Initial egg laying for skimmer usually occurs between mid-May and early June, however late arrivals or re-nesting skimmers may be outside of that window. Eggs are usually laid on successive or every other day intervals and a typical nest contains three to four (3-4) eggs with two and five egg nests being rare. Incubation of the eggs requires between 21 - 26 days and both parents share the responsibility.
Black skimmers forage in shallow tidal waters often found in the back of bays and tidal inlets. Foraging usually occurs during low tide or at night. Black skimmers do exactly that when they forage, they literally skim the surface of the water with their bill partially submerged. Upon coming into contact with a potential food item the skimmer reflexively snaps its bill closed capturing the object.
In New York skimmer are most likely to feed on:
- silversides
- killifish
- menhaden
- bluefish
- sand lance
- needlefish
Distribution and Habitat
The North American race of black skimmer (Rynchops niger niger) relies almost entirely upon marine resources for both nesting habitat as well as for forage. Located primarily within the Caribbean and Gulf of Mexico during the winter months black skimmer migrate northward beginning in early Spring to breed. The species migrates along both the east and west coasts. Migrants along the east coast arrive in New York in early April and select barrier beaches, salt marsh, and dredge spoil islands as nesting habitat. Except for a small group that continues on into Massachusetts, New York often represents the northern breeding limit of this species.
In New York black skimmer almost always form mixed species colonies with either least or common terns. The two largest colonies in New York are located only 17 miles apart and are found in Breezy Point, Queens and on Nickerson Beach in Nassau County.
Status
Currently, the U.S. Fish and Wildlife Service does not list black skimmer as threatened or endangered. However, it is protected as a Species of Special Concern in New York State. The primary reason for the Special Concern ranking is the limited number of breeding colonies in New York. The annual number of black skimmer colonies is approximately ten. However, the majority of successfully nesting birds are located at only two sites. The annual population of black skimmer is highly variable, but typically averages 490 adult pairs in New York.
Primary concerns for this species center around conflicting or competing use of limited coastal resources with human development and recreation, predation to adults, eggs, and hatchlings by both wild and domestic animals, and changing climatic variables.
Management and Research Needs
Symbolic fencing, beach maintenance, and other endangered species management actions designed to benefit the piping plover often encapsulate black skimmer nesting habitat as well.
Black skimmers are currently surveyed annually as part of the Long Island Colonial Waterbird and Piping Plover (LICWPP) survey. While this survey provides a reference for annual abundance and distribution it does not provide any measure of breeding productivity. The recently developed species conservation guide for the black skimmer calls for increasing the number of annual breeding locations coupled with a larger geographic range of stable colonies, while at least maintaining the number of breeding adults annually.
Research needs are centered on understanding marsh loss occurring along New York's coast and the potential for providing alternate breeding locations such as rooftop nesting which has shown to be beneficial to terns in southern states.