Few mice foraged in the sparse cover of the highest dune zone eleva- 

 tions. Peromyscus leucopus occupied the tfiicket and woodland habitat 

 of the more protected dune areas, while Microtus pensylvanicus domi- 

 nated those hydric bayshore habitats containing dense herbaceous 

 cover. Both habitat orientation and interspecific interactions may 

 be involved in the distributional pattern of M. pensylvanicus and 

 P. leucopus . Succession in dune zone locations results in an 

 Increased abundance of P. leucopus as shrub cover increased during 

 serai stages. Recapture distance of P. leucopus were inversely 

 related to both population size and density of shrub cover. Zapus 

 hudsonius , which was associated with moist habitats of the barrier 

 beach, had either large or unstable home ranges. (A. A. modified) 



Keywords: mammals, barrier beach habitat, ecological relationships, 

 New Jersey 



V-C-9 



Sharp, H.F., Jr. 1967. Food ecology of the rice rat, Oryzomys 



palustris (Harlan), in a Georgia salt marsh. Journal of Mammalogy 



48:557-563. 



Examination of 22 stomachs of rice rats taken in summer and fall 

 indicated a predominance of animal food, chiefly insects and small 

 crabs, although plant remains were present in several stomachs. 

 Predation on eggs and young of marsh wrens was known to occur. 

 Individuals reared in the laboratory from nestlings taken from a 

 Georgia salt marsh preferred foods of an animal source and made 

 greater weight gains when animal material constituted all or part 

 of the diet. While captives were able to assimilate both plant and 

 animal food efficiently 



(ingested energy - fecal energy ^ ^qq ^ 88-95 percent), 

 ingested energy 

 they ingested more calories when animal food was offered. A daily 

 intake level of 0.15 kcal/kcal body tissue was required to maintain 

 body weight in the laboratory; ingestion rates above this level 

 resulted in weight gains. It is concluded that during the summer 

 months the trophic niche of the rice rat in the salt marsh ecosystem 

 is that of a carnivore. (A. A.) 



Keywords: rice rat, salt marshes, food ecology, Georgia 



V-C-10 



Fisler, G.F. 1961. Behavior of salt-marsh Microtus during winter high 

 tides. Journal of Mammalogy 42:37-43. 



The populations of Microtus californicus inhabiting the salt marshes 

 of the San Francisco Bay region are subjected to daily high tides, but 



245 



