j4~v 
 
I          19/ 
winter about the sm number of quaIl am they 4id a dad ao. 
On the basis of tese three comarieon we feol eure that some cl 
has occurred In the predation threshld sc period B. Zther the t1 
has been lwered, or the threshold mechanism has been suprseded by 
other mode of popuatin behavior. 
We lean to      the pinin  that the 300 threshold has suffered a 
reuction during the studty period., The beginning of such a redaction 
already visible In 1933,34when a ae~byi~nI  operation by L.W.A. seem 
to       u  the         irn   from about 330to about 25 qui         p 
 
If the carryg cpaity has sufferedt depression, It is         sp    n 
that It shoud be so large. Presumbly the change has been in food and 
 
co  r, for there bave been 4    nown cha    s in the kind or nuber of 
 
If in food and cover it mt represeat the fablative effect of g          and

cutting of woodlots, debrahing of roadsides, loee of *oil fertility, and

intensification of famin operations.