MAMMALS OF MARYLAND 



109 



of burrows are shallow, descending to a depth of only 3 or 4 inches. 

 In orchards it tunnels its way to fallen apples, and then burrows up 

 from underneath to feed on the fruit. These mice seldom leave their 

 subterranean burrows. 



The nest of the pine vole is globular in shape, and composed of 

 almost any material the animal can procure, generally dead leaves 

 and grasses. The nest may be just below the ground surface, or, oc- 

 casionally under some shallow-rooted stump. Usually there are three 

 or four exits. 



This species feeds largely on roots and tubers, bulbs, and the bark 

 of trees and shrubs. It seldom eats green vegetation, seeds, or most 

 kinds of fruit, although it does relish apples and pears. Generally, 

 considerable quantities of roots and tubers, which presumably are 

 utilized as the bulk of the winter food, are stored in its burrows. Pine 

 voles often are responsible for depredations in orchards, where they 

 frequently girdle apple trees severely. 



This species is cyclic, and according to Hamilton (1938, p. 166) its 

 reproductive behavior undoubtedly varies from year to year as does 

 that of MicTotus. The breeding season is from early March to mid- 

 November, and small litters of from two to four young are produced. 

 The gestation period in all probability approximates the 21 days of 

 M icrotus. 



Specimens examined. — Allegany County: Oldtown, 9 miles E, 4. 

 Awne Artmdel Ootmty: Annapolis, 3 miles NW, 2; Lake Shore area, 

 2. Cahert County; Plum Point, 2 miles W, 1; Solomons Island, 3% 

 miles N, 1. Carroll County: Hampstead, 1. Charles County: Newport, 

 3; Port Tobacco, 3 miles SW, 1. Dorchester County: Cambridge, 3. 

 Garrett County: Grantsville, 1. Howard Comity: Long Comer, 1. 

 Montgomery County: Chevy Chase, 1; Kensington, 2; Montgomery 

 Knolls, 1 ; Plummers Island, 5 ; Poolesville, 1 mile NE, 1 ; Eockville, 

 2.3 miles NE, 10; Seneca, 1.3 miles W, 1; Seneca, 1% miles NW, 1; 

 Silver Spring, 1; Takoma Park, 1; Woodside, 5. Prince Georges 

 County: Bladensburg, 1; Laurel, 9; Oxon Hill, 1. District of Columi- 

 hia: 61. 



Other records and reports, — Allegany County : Green Ridge (Coll. 

 U. Md.). Baltimore Comity: Bare Hills-Lake Roland area (Bures, 

 1948: 68) ; Patapsco State Park (Hampe, 1939: 7). Prirwe Georges 

 County: Patuxent Research Center, along Patuxent River (Stickel, 

 Lucille F., 1948 : 506). 



MUSKRAT 

 Ondatra zibethicus macrodon (Merriam) 



Fiber macrodon Merriam, Proc. Biol. Soc. Washington, 11: 143, 

 13 May 1897. 



336-897 O — 69 8 



