WILD LIFE PROTECTION — WALKER 



333 



Presentations of the cash values of wnld life produced on given 

 areas well stocked as compared with the revenue from the same 

 areas or similar tracts poorly stocked or producini; farm crops of 

 limited value often can he usetl with convincing effect. Tiiis can be 

 strikingly shown by assembling such figures as are available of game 

 manmials, birds, fur bearers, frogs, turtles, or fish that have been 

 taken from known areas such as islands, lakes, counties, or States an<l 

 nmltiplying the number by the present values of such animals. In 

 many cases it will sliow that the wild stock that can be produced on 

 the area is far more valuable than the <l(»mestic products now being 

 raised. 



Fxfihcf'i'on point^ 



PROGRESSIVE UTILIZATION AND EXTERMINATION OF A SPECIES 



FlOURI 1 



In an effort to show diagrammatically or graphically the progres- 

 sive utilization and extermination of a species,- the design shown 

 in Figure 1 has been developed. It is an attempt to enable one to 

 visualize what to-day is probably the greatest problem with which 

 the wilddife a<lministrator is confronted. It is based upon the fact 

 that a given area of land or water or both can continuously support 

 only a certain maximum number of breeding animals and their prog- 

 eny until tlie repi-odiictive stage of such progeny is reached. There 

 are, of course, innumerable factors that affect this condition, but the 



•This and certain otlior diaKianiH and pxtracts hiTPln are taken from the autbor'.s 

 paper Getting Public Support for .MnnimnI Prot«>ctl«n published in the Journal of 

 Mammalogy, vol. 9, No. 3, pp. 195-200, August, 1928. 



