8 THE CONDOR Vol. XSi 
were opening some grubless acorns, they were really after the grubby ones. 
For instance a few cases were noticed where sound nuts had been opened, but 
where the meat was still in place—as though the bird had opened the nut in 
the expectation of getting a grub, had recognized its mistake, and had then 
discarded the nut. But systematic, quantitative study of nut remains through 
a winter would be necessary to prove such a selective process of food con- 
sumption as is here indicated. 
On this visit some attention was given to the hole-drilling itself. One tree 
in particular contained a considerable number of perfectly fresh acornless 
holes, some of which were completed while others were in various stages of 
advancement. That these had really been only recently made seemed highly 
probable. But if so, wherefore had this been done, the storing period for the 
season having ended some four months ago? I have seen no indication that 
acorns are garnered at any other time than in early fall when the crop 1s freshly 
ripe. 
Another observation at this time was suggestive of an answer to the ques- 
tion just asked, this observation tending to confirm the occasionally expressed 
surmise that the hole-drilling is not primarily for acorn storing but is an inel- 
dent to the bird’s pursuit of insects in the bark itself. An instance was found 
of a dead pine, the bark of which showed many small holes made by an insect, 
probably. Some woodpeckers, presumably the California, had been prodding 
the bark of this tree almost certainly after the insects responsible for these 
minute holes. Although in some cases the woodpecker work was rather dif- 
fuse, and quite unlike the clear-cut acorn storage holes, in other cases the per- 
forations were quite similar to those made for acorns. 
Assuming, now, that this bark puncturing was done by the California 
Woodpecker (which, however, is not quite certain), an instance is furnished 
which might be interpreted as reminiscent, so to speak, of the bird’s original 
purpose of hole drilling. Though very fragmentary, this observation was suf- 
ficiently suggestive to warrant considerable effort at extension. But the cir- 
cumstances under which this mid-winter visit was made were such as to pre- 
clude the possibility of following the point farther then. On later visits a few 
additional facts were observed bearing on the general question of hole drilling. 
These will be presented in due course. 
My next visit was on June 7-9, 1920. Several of the trees from which the 
acorns had been partly used in February, were now almost entirely acornless, 
not even empty shells being left in the holes, excepting here and there. Exam- 
ination of shell fragments in the litter furnished evidence that the meats of 
sound nuts had now been used as well as grubs from ‘‘wormy’’ ones, this evi- 
dence consisting in applying the criteria already mentioned as to shell remains 
of sound and wormy nuts. Many shell pieces, some of them half shells or even 
more, were seen containing no remnants of meats, but likewise no tracts of 
worm leavings. The meats had surely been removed, in all likelihood, by the 
woodpeckers, and for food. But certainty, on the last two points, was impos- 
sible since my efforts to catch the birds in the act were as little successful on 
this as on previous visits. It is, of course, possible that sound nuts opened by 
woodpeckers and cast aside when found to contain no erubs, may have been 
deprived of their meats by other animals. as mice or rats. However, ample in- 
direct evidence of the sort here indicated, coupled with the direct evidence 
afforded by examination of stomach contents (Grinnell and Storer, Yosemite 
