U. ». r - 





United States Department of Agriculture "~ 

 Bureau of Eiolo.'-ical Survey 



Vrildlife P.osoarch ajid Management Leaflet BS-132 



'./ashin-ton, D. C. 



At)ril 1C39 



SOME CALI?0.?aHA !-:iLDLIF3-F0HZST R2LATI01TSHIPS l/ 



Bv E. E. Horn, Biologist, Section of '.'ildlife Surveys 

 Division of ^'ildlife Hcscarch 



Contents 



Pago 

 Effects of forest -wildlife inter- 

 actions 1 



Type of forest affects \^ldlife 2 



Wildlife affects tj-pe of forest. 3 

 Results on California study 



areas . , 3 



EFFECTS or FOREST -'7ILDLIEE INTERACT I OiTS 



Forests, with their diversity of conditions, are the homes of nu- 

 merous forms of v/ildlife. The^'- are, indeed, communities of interrelated 

 living organisms. The lives of the forest plants and animals are so close- 

 ly inter-Joven that it is impossiolo for one of them to function without 

 influoncing others. These interactions largely determine the nature of 

 the hiotic comrmznity. 



The animals in any connunity depend, directly or indirectly, u'oon 

 plant n for food and, in man;"- instances, for shelter. The type of vegeta- 

 tion availalile for food and cover determines, in part, the species of a:i- 

 imals that can exist on an area. All animals display preferences, in these 

 respects, that may or may not prevail to an exclusive extent. The results 

 are tv/ofold: (l) If an animal is unadaptable to a given environment and re- 

 quires a definite type of food or cover, plants may "be an important factor 

 in determining its abundance and distri^oution. In such circumstances there 

 will be a someviiat constant ratio between the abundance of host plants and 

 that of gi^est animals, though over a long period of time the numbers of both 

 may fluctuate greatly, (2) If the aaiimal is highly adaptable, changing 

 readily from one food to another and maintaining its numbers, it is likely 

 to exert a marked influence upon the plant community. 



1/ Revised from paper presented at the Third North American 'iildlifc 

 Conference, Baltimore, Md, , Fcbruiiry, 1933 (Trans., pp. 376-380, 193S) . 



