122 Game Survey of the North Central States 



INTERPRETATION OF PLANTING EXPERIENCE 



This discussion has been deferred in order to first present a rough picture 

 of how established populations behave. We are now ready to attempt to decipher 

 something about the reasons why some plantings have been a success and others 

 a failure. 



Summary of Experience. While Hungarian plantings have survived in 

 a narrower belt of more irregular outline than that marking the survival of pheas- 

 ants plantings, it seems clear that both species are alike in exhibiting the following 

 characteristic behavior when planted in the north central region: 



(1) Plants usually breed normally for at least one year, regardless of where 

 made. 



(2) In suitable portions of the northern zone, this continues indefinitely. 

 The plants spread and become established as wild populations. 



(3) In the southern zone they do not become established. Usually within 

 three years after planting the stock has either disappeared, or has been reduced 

 to a few straggling and apparently non-breeding adults. Sometimes the stock 

 disperses at the end of the first breeding season. 



(4) In both northern and southern zones, captive pheasants on game farms 

 are successfully bred for long periods. This captive stock is of identical origin 

 with the planted stock. Hungarians are not successfully bred on game farms 

 in either zone, but this is due to their reluctance to produce eggs in captivity, and 

 probably has no bearing on the survival of plants. 



These are the facts. Behind them must lie some cause or reason. What is 

 it? 



Popular Interpretations. When sportsmen, game wardens, farmers, or 

 even ornithologists are asked why pheasants and Hungarians have failed to es- 

 tablish themselves, they almost invariably allege one or more of the following 

 reasons. 



(a) The plant was shot out by law violators. 



(b) The plant was destroyed by "vermin." 



(c) The plants were of insufficient volume or duration. 



(d) The planting stock was improperly released and did not become located. 



These popular interpretations will be considered in the following analysis. 



Kinds of Causes. The causes of success or failure of plants are of three 

 possible kinds: 



(1) The character or condition of the stock planted. 



(2) The character of the environment in which planted. 



(3) The method of planting, and the protection and care given the plant. 



The character of the pheasant stock planted in the north central region is 

 known to this extent: It consists of the hybrid birds characteristic of north 



