Occasional Papers of the Museum of Zoology 5 



The work was supported by the Michigan Geological and 

 Biological Survey. Dr. Alexander G. Ruthven directed the work 

 and gave much assistance in securing the needed collecting equip- 

 ment. Much help was given by George R. Fox, Director of the 

 Warren Foundation, not only in getting to and from the camp 

 at the Woods and in numerous other courtesies, but also in infor- 

 mation about the Woods and about the mammals there. The 

 plant identifications were made by ^Ir. C. Billington. 



The figures following the specific names in the lists of mam- 

 mals from each habitat indicate the number of individuals trapped, 

 shot, or seen and positively identified in that habitat. 



Natural Habitats 

 Aquatic habitat: 



Musiela vison mink. Mink. Reported. 



Fiber zibethicus zibethicus. Muskrat. Reported. 



Mink and muskrat are reported by residents to occur in the 

 Galien River in and near Warren Woods, but I was unable to 

 secure any specimens though traps were set for them; neither 

 did I see any signs of their presence. 



Buttonbush-swamp habitat: 



Peromyscus leucopus noveboracensis. Northern white-footed mouse. 8. 

 Mus musculus musculus. House mouse. 2. 



A large buttonbush swamp occurs in the preserve just south 

 of the Galien River, but around this the native trees have been 

 cut away and over its accessible edges it has been heavily pas- 

 tured, so that it is not at all in its natural conditions, and it was 

 not trapped. In the unpastured flood-plain north of the river 

 there is another buttonbush swamp of several hundred yards 

 extent. This latter area was the one selected for study. 



In this t^-pical swamp the buttonbush, Cephalanthus occi- 

 dentalis, is practically the only plant present. It thickly covers 

 the area with its tangled branches, which grow to heights of four 



