44 
Sarah S. Robinson and David S. Lee 
some areas. However, neither author had new records for the region east 
of the Chesapeake Bay. Allen (1950) reported that the species had in- 
vaded the Delmarva in the previous 50 years, noting that it first appeared 
near Galena, Kent County, Maryland, around 1900. This is apparently 
the only published report of its occurrence east of Chesapeake Bay. 
Casual interviews with residents of the area confirmed to us that 
groundhogs had recently appeared there, although agreement on the 
length of time they had been established was lacking. 
It is interesting that we have few records from south of Talbot and 
Caroline counties, Maryland, and Kent County, Delaware, despite inten- 
sive field work. This may reflect the change in soil composition which 
occurs in this general area. The well-to-poorly drained sandy loam and 
sandy clay loam soils (Sassafras and Sassafras-Fallsington associations), 
which are nearly continuous in the northern portion of the Delmarva, 
become fragmented here. The 75- to 125-cm deep loamy soils are mostly 
replaced by more sandy soil associations, and much of the area is dis- 
sected by extensive Spartina marshes which would further limit dispersal 
of Marmota. 
The southern limits of the groundhog on the Delmarva appear to 
terminate at the northern limits of pure stands of Loblolly Pine, Pinus 
taeda (Conant 1945). This change in community character appears to 
have effectively limited the natural dispersal of several vertebrate species: 
the Whip-poor-will, Caprimulgus vociferus, and Scarlet Tanager, Piranga 
olivacea (Stewart and Robbins 1958); and the Red-spotted Newt, 
Notophthalmus viridescens viridescens, Spotted Salamander, Ambystoma 
maculatum, Northern Red Salamander, Pseudotriton ruber ruber, and 
Northern Two-lined Salamander, Eurycea bislineata bislineata (Harris 
1975). Also, disjunct populations of at least six species of upland plants 
occurring in communities of Coastal Plain hardwoods on the peninsula 
are excluded from areas which support extensive stands of P. taeda 
(Franz and Lee 1976). 
Delaware Records 
Coastal Plain: New Castle County. —Road shoulders/fields, 3 mi. 
(4.8 km) s of Middletown on SR 896; 1973 (Matapeake-Sassafras soil 
type). Road shoulders/hardwood forest, 8 mi. (12.9 km) n of Smyrna on 
US 13; 1973 (Matapeake-Sassafras). Fields, Lums Pond State Park; 1974. 
US 301 between Summit and Middletown; 1972. Kent County.— 
Dikes/fields, Bombay Hook National Wildlife Refuge; 1974-1976. 
Fields, 7 mi. (1 1.3 km) s of Leipsic on SR 9; 1976 (NCSM 2933). Sussex 
County.— Fields, Prime Hook Wildlife Refuge; 1974 (sandy loam). 
Maryland Records 
Piedmont Plateau: Cecil County. — Riv er floodplain, Conowingo 
and Rt. 222, 5 mi. (8.1 km) s of Conowingo; 1968-73. Rising Sun; 1969. 
