HAMILTON: MAMMALOGY IN NORTH AMERICA 



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siderable monetary loss or a threatened human pandemic appears miminent. 

 When the 1924 outbreak of hoof-and-mouth disease occurred in California, more 

 than 22,000 deer were poisoned on the Stanislaus National Forest of California. 

 The disease was checked, and the deer soon regained their former abundance. 



Mammalian Eesearch 



It was inevitable that research studies should emphasize the species which are 

 of economic significance. Following the early trend of systematic mammalogy, 

 when species were described, their distribution plotted, and their practical sig- 

 nificance determined, emphasis was directed toward the acquisition of detailed 

 knowledge concerning individual species. With the essential features of the dis- 

 tribution of most of our commoner species mapped, the main categories in the 

 life histories have been catalogued, if only in a brief, superficial manner. To be 

 sure, this advance in our knowledge of the rich North American mammalian 

 fauna has not kept pace with the more numerous bird species, but the reason is 

 quite apparent. 



In the early years of field investigation, emphasis was placed on regional lists, 

 annotated with brief accounts of the habits of the included species. These reports 

 followed the pattern of some of the early North American Fauna series. In these 



Figure 2. By their numbers alone, the teeming hordes of ground squirrels in west- 

 ern North America provide an unparalleled opportunity for research. Behavior, activity 

 and population studies, to cite a few, are indicated by the abundance of these little 

 mammals. The golden-mantled ground squirrel, Citellus lateralis, was photographed in 

 Estes Park, Colorado, on July 1, 1941. 



