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Migratory Stopovers . Many places, especially along the eastern shore, 

 are utilized by shorebirds, birds of prey, and passerines passing 

 north or south. The birds pause to feed and rest for a few days before 

 resuming their migratory flights. Wherever possible such areas have 

 been located. 



MARINE INVERTEBRATES 



Clam and oyster beds do not exist iii vacuo but are quite intimately 

 related both to the bay or estuary where they are located and the nearby 

 marshes which provide the production which the shellfish, in part, harvest. 

 Since shellfish are sessile as adults some especially oysters 

 (Crassostrea virginica ) which lack the siphon that permits clams ( Mya 

 arcnaria , Mercenaria) to be buried by silt, are quite sensitive to siltation, 

 Clams are also dependent on detritus from marshes for food, especially 

 in the younger stages. Adult crabs ( Callinectes sapidus ) may feed in turn 

 on smaller detritus feeders. Although crabs are quite mobile and migrate 

 during the winter into deeper water near the mouth of the Bay, their 

 attraction to certain areas in the summer reflects the high productivity 

 of those areas. These places have been identified wherever possible along 

 with oyster bars and clam beds. 



RANGE PHENOMENA 

 Since both plants and animals are closely tied to their habitats as 

 well as their niches, their ranges can usually be rather closely plotted. 

 This is certainly true for the larger animals and woody plants. Because 

 of its position halfway up the Atlantic Coastal Plain, the Bay region 

 includes many edns of range or outlying populations. 



