Black-bellied Plover Habitat Model
go to: USFWS Gulf of Maine Watershed Habitat Analysis
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Draft Date:
June 2001

Species:
Black-bellied plover, Pluvialis squatarola

Use of Study Area Resources:
Migration. Black-bellied plovers breed in the high Arctic of North American and Eurasia. Their winter range in the New World extends from British Columbia east to Massachusetts, and south along both coasts through Central and South America. (Paulson 1995). Within the study area black-bellied plovers forage and roost primarily at coastal sites during northward migration (Pierson et al. 1996), returning southward via more interior routes.

Habitat Requirements:
On the coast black-bellied plovers typically forage on sandy and muddy intertidal flats for polychaetes, bivalves, snails, amphipods, and crustaceans (Paulson 1995).  In the interior they may use uplands adjacent to water bodies, shallow freshwater wetlands, flooded pastures or agricultural fields, and even dry grasslands where the vegetation is short and sparse (Helmers 1992).   Pierson et al. (1996) identified a number of Maine lakes regularly used by black-bellied plovers during drawdowns  Prey at inland sites includes insects, invertebrates, and freshwater crustaceans (Paulson 1996).  

McCollough (1981) observed the highest rates of foraging and capture on exposed, well-drained coastal mud flats, higher above the water's edge than the areas used by other shorebirds. Thus, they typically feed over the upper and mid portions of the intertidal zone. Feeding on tidal flats is more regulated by tidal cycles than daylight, and nocturnal foraging is as common as diurnal (Paulson 1992, Burger et al. 1977). Roosting habitats include sandbars, spits, or flats above the high tide line (Helmers 1992), and high salt marshes (Maisonneuve et al.1990, Paulson 1995).

Model:
The habitat model relied on abundance/occurrence information from a Maine Department of Inland Fisheries and Wildlife (MDIFW) shorebird coverage, the Manomet Bird Observatory's International Shorebird Survey (ISS) database for Massachusetts and New Hampshire, and Pierson et al. (1996) for additional inland sites used by black-bellied plovers in Maine. This occurrence information was used to select the general localities (polygons or buffers around observation points) used by the species. Environmental data sets (bathymetry and wetland cover type) were used to identify areas within those localities likely to have been used. The ISS data specified the observation locations only to the nearest geographic minute, and Pierson's observations also were somewhat general. Therefore, all suitable cover types (see table, below) within the MDIFW polygons or within a 1 km radius of the point data were regarded as having the respective levels of use for that observation.  Areas having appropriate cover types but without observation data were given a reduced score (see below).

NWI Designations (wetlands only)	Cover Types	Cover Suitability (0 - 1 scale)
	Upland deciduous forest
	Upland coniferous forest
	Upland mixed forest
	Grassland
	Upland scrub/shrub
	Cultivated
	Developed
	Bare ground
PEM, L2EM	Lake/pond, emergent vegetation	0.5*
PFOcon	Palustrine forest, conifer
PFOdec	Palustrine forest, deciduous
PSSdec	Palustrine scrub shrub, deciduous
PSScon	Palustrine scrub shrub, conifer
PAB, L2AB	Lake/pond, aquatic vegetation
L1UB, PUB	Lake/pond, unconsolidated bottom	0.5*
L2US	Lake, unconsolidated shore	1.0
L2RS	Lake, rocky shore
R1UB	Riverine subtidal unconsolidated
Rper	Riverine perennial
E1AB	Estuarine subtidal vegetated
E1UB	Estuarine subtidal unconsolidated bottom
E2AB	Estuarine intertidal algae
E2EM	Estuarine intertidal emergent	0.5
E2RS, R1RS	Estuarine, tidal river rocky shore
E2SS	Estuarine intertidal shrub
E2US, R1US	Estuarine, riverine intertidal unconsolidated shore	1.0**
M1AB	Marine subtidal vegetated
M1UB	Marine subtidal unconsolidated bottom
M2AB	Marine intertidal algae
M2RS	Marine intertidal rocky shore
M2US	Marine intertidal unconsolidated shore	1.0**
NOTES	*included only if within 1 km of known site with regular draw-downs **upper and mid intertidal only

Habitat Suitability Scoring: Sites with black-bellied plover occurrences and having any of the suitable landcover types (see table) first were scored according to level of use. If a site had 5 or more birds observed at any time, the suitability index = 1.0; else, if any birds were present, or use was expressed as a narrative (Pierson et al. 1996) the suitability index = 0.5. This value was then multiplied by the landcover score.

Suitable unconsolidated coastal and lake shore cover types outside of the observation/occurrence polygons were scored 0.2, and tidal marsh scored 0.1 as potential foraging habitats.  All tidal (coastal) areas were filtered to include only wetlands above the lower intertidal zone.

Sources:

Burger, J., M. Howe, D. Hahn and J. Chase. 1977. Effects of tide cycles on habitat selection and habitat partitioning by migrating shorebirds. The Auk 94:743-758.

Helmers, D.L. 1992. Shorebird Management Manual. Western Hemisphere Shorebird Reserve Network, Manomet, MA. 58 pp.

Maisonneuve, C., P. Brousseau and D. Lehoux. 1990. Critical Fall staging sites for shorebirds migrating through the St. Lawrence System, Quebec. Canadian Field-Naturalist 104:372-378.

McCollough, M.A. 1981 The feeding ecology of migratory semipalmated sandpipers, short-billed dowitchers, semipalmated plovers, and black-bellied plovers on staging areas in eastern Maine. M.S. thesis. University of Maine at Orono. December 1981.

Paulson, D.R. 1995. Black-bellied plover (Pluvialis squatarola). In A. Poole and F. Gill (eds.) The Birds of North America, No. 186. The Birds of North America, Inc. Philadelphia, PA.

Pierson, E.C., J E. Pierson and P.D. Vickery. 1996. A Birders Guide to Maine. Down East Books, Camden, ME.