MAMMALS OF MARYLAN1> 



113 



larger fluctuations in population level in Maryland. With this in mind, 

 Harris (1952, p. 13) lists the muskrat catch on approximately 600 acres 

 of marsh on the Nanticoke River, Dorchester County. In 1937, the 

 total catch of muskrat on this marsh was 2,417 animals (4.0 animals 

 per acre). By 1950 the catch on this same marsh had dropped to 150 

 animals, or 0.2 animals per acre. On a Statewide level, the total catch 

 of muskrat was estimated at 2 million in 1938. In 1949, when Maryland 

 first began to keep accurate records of the muskrat catch, only 228,548 

 animals were reported trapped throughout the State. By 1957 this 

 figure had dropped to a low of 112,348 muskrats. The 1967-68 catch was 

 reported as 139,000. 



These figures show that the muskrat population has been experi- 

 encing a decline over the past 25 years, and since the muskrat is an 

 economically important animal, there has been considerable specula- 

 tion and research devoted to the reason, or reasons, for this decline. 

 Hardy (1950, pp. 8-9, 27) records the opinions of the trappers them- 

 selves regarding this decline, which includes such ideas as there being 

 a definite ecological relationship between muskrats and domestic hogs. 

 These trappers stated that with the fencing in of property in Dor- 

 chester County the hogs were no longer able to root in the marshes 

 and, hence, the ecological relationship of the two species was destroyed 

 and the muskrat population declined. Another theory maintained by 

 some of the trappers is that owing to various causes there has been a 

 great increase in the number of eels in Dorchester County waters and 

 that eels enter the muskrat houses and consume young. Other ideas are 

 that the muskrat decline is due to increased predation by raccoons 

 and foxes ; a "dreadful disease" ; floristic changes ; "trapping under" 

 (placing the tra^p in underground leads) ; and high water. Hardy 

 (1950, p. 27) notes that some of these factors may have been operative, 

 but that it can safely be assumed that the diminishing population of 

 the muskrat in Dorchester County has been brought about by a com- 

 bination of ecological and environmental changes rather than by any 

 single factor. Harris (1952, p. 36) points out that his study on Dor- 

 chester County muskrats did not answer the question why there has 

 been a decline in their numbers, but it did show that the combination 

 of ipredation and a reduced capacity of the marsh to support muskrats 

 may prevent a rapid increase in the muskrat population. 



Specimens examined. — Anne Arundel County: Broadwater, 1. Dor- 

 chester County : Blackwater National Wildlife Refuge, 8. Frederick 

 County: Jefferson, 1. Montgomery County: Forest Glen, 1; Kensing- 

 ton, 1 ; Sligo Branch, 1. Prince Georges County : Beaverdam Creek, 1 ; 

 Beltsville, 1; Branch ville, 3; Lanham, 2; Laurel, 147. District of 

 Columbia: 6. 



