Cape Hatteras National Seashore
Description: Cape Hatteras National Seashore encompasses more than 70 miles of barrier islands including much of the area often referred to as the "Outer Banks." It is a diverse landscape and one of the best examples of a mid-Atlantic barrier island system. The Seashore is relatively low, with average elevation approximately 6 feet above sea level. The site varies in width from about 200 feet to nearly 3 miles. The island system consists of Holocene sand ridges sitting on Pleistocene mounts that slowly migrate westward due to rising sea levels. The western boundary extends 150 feet into Pamlico Sound. Habitats include sand flats, barrier beach/dune and salt marsh.
Cape Hatteras National Seashore has substantial numbers of spring and fall migrating PIPL (16-24), WILL (3,000), Red Knot (4,700), Sanderling (35-40,000) and other shorebirds (20,000). Data is from NC Audubon IBA. Park biologists are currently conducting some ISS surveys on the seashore. With additional personnel and/or funding, this effort could be expanded to include Ocracoke Island, Clam Shoals and Oregon Inlet.
Selection Bias: Much of the sound side of the Seashore is difficult to access and may contain Type 1 shorebird habitat.
Measurement Error: Unknown.
Measurement Bias: Unknown.
Pilot Studies: Aerial surveys of the Park may be needed to determine additional staging areas and Type 1 and 2 habitat.
Local Contacts: Marcia Lyons, Cape Hatteras National Seashore.
Site 1: South Point of Ocracoke Island
Description: At the south tip of Ocracoke Island, extensive sand flats reach into Pamlico Sound. This is the southernmost point of Cape Hatteras National Seashore. From NC Route 12, there is a sand road (known as South Point road or Ramp 72) leading out to the beach (~2.5 miles). It can be approached with a 2-wheel drive vehicle, but a 4x4 or legs are needed to get from the beach to the flats (~1.0 mile to the furthest point). The site includes beach and extensive sand/mud flats and backs up to a Spartina/Juncus marsh.
Approximately 450 acres are closed to the public from late March to early September for breeding Piping Plovers, American Oystercatchers and colonial waterbirds. From early September through October, the closure is modified to include a much smaller area for migrating shorebirds. This may extend into the winter next year for wintering shorebirds. Solitary Sandpipers, Spotted Sandpipers and yellowlegs are often seen along the ditches, running along the side of the sand road leading to the beach, more so than out at South Point proper.
Low tide is best for surveys along the beach, though good numbers of birds may be seen at low and high tides. Vehicles are allowed on the beach outside the closures, so early in the morning before people are out is also a good time. The breeding season closure could hamper viewing due to its size, but many of the good shorebird sections could be seen with a scope. Binoculars and a scope can also be used in other seasons.
The entire length of Ocracoke Island is great for shorebirds feeding along the surf at low tide. Species observed include: Sanderling, Willet, Ruddy Turnstone and Black-bellied Plover. This is also one of the best sites for Red Knots.
Survey Method: Ground survey. The surveyor should use a scope and walk the sand flats on the Pamlico Sound side of the island tip at mid or high tide. Note: the tides in Pamlico Sound are often driven by wind and the site should not be surveyed on a low wind tide, as birds may be too distant. Spring surveys will be restricted by beach closures, but surveyors may be able to arrange limited access into closed areas if necessary.
Selection Bias: Area closings could introduce a selection bias. Any bias would be small as the majority of the Type 1 habitat is still visible from the spring survey point.
Measurement Error: Unknown
Measurement Bias: Unknown
Pilot Studies: None
Local Contacts: Marcia Lyons, Biologist, Cape Hatteras National Seashore
Site 2: Clam Shoal
Description: Clam Shoals are located six miles North of Hatteras, North Carolina out in Pamlico Sound. The shoals are very flat and frequently submerged by wind-driven tides. Water levels at this site may be highly variable from day to day. At low water and with Easterly winds, the shoals are exposed and may be up to five miles long. Westerly winds will put the shoals under water. Species present include 8,000 DUNL and 800 BBPL. The site is primarily a feeding spot, but it can support upwards of 5,000 birds as a roost site when the weather conditions are right.
Survey Method: Access to the site is by boat or plane only. According to Dave Allen, boat access should ideally be handled with a seaworthy V-hull, 20 foot boat. There are at least two boat launches on Hatteras Island: “Teaches Lair” and “Hatteras Marina” that provide access. Due to the size of this site and its remoteness, surveys will take most of a day. Winds can be very strong in the sound, so boat access may not always be possible. This is primarily a feeding site, so surveys should be done at mid or falling tide.
Selection Bias: None
Measurement Error: Unknown.
Measurement Bias: Unknown.
Pilot Studies: None needed.
Local Contacts: Dave H. Allen, North Carolina Wildlife Resources Commission.
Site 3: Oregon Inlet Shoals
Description: The Oregon Inlet shoals, also known as Green Island, are located immediately west of Oregon Inlet in Dare County. They are 50 - 75 acres of exposed sand shoal/island in the Cape Hatteras National Seashore, within NPS boundary 35.76437 N, 75.5321 W. These shoals change shape and even location every year, depending on storms. The site is posted for breeding birds and patrolled by the NC Wildlife Resources Commission. Part of the site may be closed off for migration. Access is by boat from nearby Oregon Inlet Marina. Surveyors will need to supply their own boat since Cape Hatteras NS has none available.
According to Sidney Maddock, vegetation was growing on the highest parts of Green Island by the late 90’s, and now it has advanced considerably. At high tide, 70% of the exposed areas are covered in vegetation. As a result, there has been a decrease in available roosting habitat for wintering Piping Plovers at the site. Other shorebird species observed include: SAND, BBPL, LESA, DUNL, DOSP, GOSP, SEPL and AMOY.
There are no mammalian predators on Oregon Inlet shoals, but disturbance to shorebirds is high due to the presence of off-road-vehicles, especially on weekends. Meanwhile, Oregon Inlet is an important shorebird migration site, as well as a wintering site.
Survey Method: Ground surveys should be conducted at this site. A scope is recommended. Access to migration closures may be possible if a permit can be obtained from NPS. Sidney Maddock, who carries out annual Piping Plover recovery work at this site, has a boat and a permit to access the site and may be able to assist with surveys.
Selection Bias: This could be a factor if access to Oregon Inlet cannot be arranged and surveys are prevented.
Measurement Error: The continuing advance of vegetation at this site may result in measurement error.
Measurement Bias: Unknown
Pilot Studies: None needed.
Local Contacts: Marcia Lyons, Biologist, Cape Hatteras N.S.; Sidney Maddock, possible ISS Cooperator for the site.