

MAMMALIAN LIFE-HISTORIES. 3 



suffice for ordinary work. A bump of resourcefulness on the part of 

 the investigator is perhaps the most important item of initial equip- 

 ment. Some of the problems in the life histories of birds and mam- 

 mals are full of difficulty, and require special equipment in particu- 

 lar cases. Many methods remain to be devised, and instruments to be 

 invented. 



Less refined modes of inquiry should give way to intensive inves- 

 tigations of a quantitative character as rapidly as practicable. There 

 is great need for the development of the ecologic method of approach 

 in the study of the animal and its environment. Field plot or 

 quadrat methods should be combined with observations on the 

 behavior of animals under confinement, the whole based on a 

 thorough knowledge of normal field conditions over wide areas. Xo 

 attempt is here made more than to refer to the development of this 

 important side of the work, with the permanent field stations, spe- 

 cially trained personnel, and comparatively elaborate equipment 

 which it implies. 



The increasing employment of the camera in the study of habits 

 is peculiarly desirable. Dr. Frank M, Chapman (1900, p. 1) states 

 the case for the scientific value of bird photography in the following 

 words: 



There are certain matters, such as a bird's song, its time of migration, etc., 

 which must be set forth with the pen ; there are others, such as its haunts, nest- 

 ing site, nest, eggs, the appearance and development of its young, where the 

 camera is so far superior in its power of graphic representation that it is a 

 waste of time to use the former when circumstances permit the utilization of 

 the latter. 



Though much less used in connection with mammal study, due per- 

 haps to the nocturnal habits of these animals and the lesser accessi- 

 bility of their haunts and homes, the value of the camera in this 

 province can scarcely be overestimated. Photographs should be 

 secured .of living animals in characteristic attitudes, of specimens, 

 especially those freshly killed, of animals in traps, of characteristic 

 food plants or other vegetation, and of noteworthy features of 

 topography or environment. Photographic record is desirable also of 

 tracks of animals, their systems of runways, beds or shelters, nests, 

 piles of stored food or "hay," feces, claw marks on trees, cropped 

 vegetation, and general habitat. The animal-portrait work of the 

 day is of such high character that ordinarily it will not be possible 

 for the biologist in the field to attempt to equal it ; but it is of such 

 importance that wherever possible a professional animal-photog- 

 rapher should be a member of a field party. 



