R~U.S.N. 2/26/32 



Then there is the pocket gopher. Is the daniase it does "by its 

 burrowina activities offset by the good it does in stirring up and 

 working; the soil and opening it up so the water can get dovm? That, you 

 may guess, depends on where the burrowing is done, on the use made of 

 the land, and on how many pocket gophers aro at work. This last considera- 

 tion brings up a question tr^t hasn't been answered yet: What are the 

 main causes of differences in numbers of different kinds of animals or 

 plants at different times? 



Woodpeckers are generally helpful to trees by destroying injurious 

 insects. However, woodpeckers have been suspected at times of performing 

 anything but sanitary tree surgery, for if one sticks his bill into a 

 diseased tree, and then flies off to attack another tree, it may be 

 responsible for spreading that disease. 



On the Kaibab National Forest the mule deer became so numerous for 

 a time that they overgrazed the range and threatened to destroy both the 

 range and themselves in doing it, while other animals under the same sort 

 of protection hardly increased in numbers at all. 



Of course, all these relationships which I have merely brought to 

 your attention have been studied for many years by scientists and scientific 

 organizations here and there. But not enoiigh and not fast enough to meet 

 the need for information. It is to help out in these needed studies that 

 the Biological Survey, under the provisions of the McIIary-McSweeney Act, 

 has recently mapped out a comprehensive program of research to find the 

 facts about these coniplex relationships between many plants and animals. 



Game management probler-is, for instance, have become prominent. Dr. 

 Boll explains that it is becoming very evident that gaine management must 

 play an important part in the future developnent and use of our gaaie and 

 wild life resources. But in order to manage properly we must know what 

 we are doing. The first thing is to learn just vhat the conditions are, 

 and wl-;at we have to deal with, in the various parts of the country. To 

 that end, the Biological Survey now has several men in the field, making 

 surveys to find out what wild life is actually here and v;hat the animals 

 are doing. 



Don't get the idea that this is to be just a sort of still picture 

 of what is on hand at any particular time; there are few still pictures 

 in nature. The plan of the bureau is to keep constant track of the ever- 

 shifting forces in nature and the varying changes that they cause. The 

 prograa in its general features is a permajient prograra of research into 

 the relationships of plants and animals in forest, field, and stream. 



Consider beasts of prey, for instance. Tnat are their good points 

 and what their bad? What is their real value in keeping down the 

 numbers of other animals from the standpoint of the health of those 

 other species? Wh-t is the value of these predatory animals for fur? 

 On the other hand, how about the harm they do? Are they unduly destructive 

 to game, or livestock, or other forms of life? Then, too, there is the 

 problem of disease among wild life, as well as among domestic animals 

 and human beings. Furtherraore, there is a serious possibility of diseases 



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