12 THE CONDOR Vol. XXIII 
had been done. Such a case readily suggests that the hole-drilling habit may 
have been connected originally with the habit of probing cracks and other 
natural cavities in dead trees while searching for insects. But since there were 
probably more holes in this tree not connected with cracks than were so con- 
nected, but were in the solid wood, we may suppose the crack-probing instinct 
being a generalized one, easily over-flowed as one might say, first to produce 
the hole-drilling habit in solid wood of the same dead tree, and afterward to 
the bark of live trees containing no cracks. 
And by a parallel development the present acorn storing habit may have 
heen perfected. At the beginning this may have operated only in using cracks 
and decay cavities, in dead trees for storing, but later extended to the drilled 
holes of the same trees, and later still to those drilled in the bark of living trees. 
Conclusive evidence that nut-eating rodents (squirrels, rats) prey upon 
the acorns stored by the woodpeckers was first obtained on the present visit. 
Two trees were found on which the bark immediately around acorn holes had 
been gnawed by rodents, as unmistakably proved by the tooth marks. The 
acorns were gone from some of these holes, but not from all, thus showing that 
the marauders had failed in some of their efforts. 
Squirrels (the Anthony Gray Squirrel) and rats (Southern Brush Rat) 
are both common hereabouts, and one or the other of these was in all proba- 
bility the culprit. This observation clearly indicates an advantage in counter- 
sinking the nuts, as one may say, in the holes, and also in ‘‘hammering them in 
tight’’. With a little care and extra work the nuts could be so stored as to 
protect them pretty effectually against rodent pillage. And to a great extent, 
though by no means wholly so, as we shall see later, the storing realizes this 
protection quite well. 
The next trip to the locality was planned with reference to the harvest 
time for the acorn crop of 1920. October 18-19 was the date on which it was 
made. The crop seemed to have been only moderately good this year. This 
was indicated by the fact that almost no nuts still remained on the trees, that 
very few were on the ground under some trees, though under many others a 
fairly generous number were present, and finally that while a goodly number 
of the storage trees had been moderately stored with fresh nuts, several of 
those most richly stored last year had received none or only a few this year— 
though, of course, the season was not far enough gone to make it impossible 
that more garnering would yet be done. 
Attention was again given to the two trees having many holes but no 
nuts, mentioned in connection with previous visits. As before, neither of these 
contained a single nut or any other signs of having been recently worked at 
by the birds. Since this makes the third consecutive season in which these 
trees have been observed to be unused, it looks as though they are wholly 
abandoned. The general appearance of desertedness of one of them especially 
favors this conjecture. 
The group of trees of which storage-tree A is one, presented the most in- 
teresting facts this time. These were now quite as heavily stored as when first 
seen, July, 1919, but not more than one-half of the nuts were of the 1920 erop, 
and very many of them were clearly the same as those seen on the first and all 
the intervening visits. The state of weathering of nuts, previously mentioned, 
was the decisive pointer to this conclusion. The darkened condition of the 
sound meats of the old nuts, referred to in connection with the visit of June, 
