July, 1922 ACTIVITIES OF THE CALIFORNIA WOODPECKER 113 
goes wrong to the extent of storing pebbles instead of acorns, thus defeating en- 
tirely the purpose of the instinct.’ 
On this point I have no observations of my own. But two more undoubted 
cases are reported by other persons. One of these is by Mr. A. B. Howell of 
Pasadena, California; the other by Mr. Henshaw in the article mentioned above. 
Besides Te four depinitely: known eases of this blunder now on record, several 
others have been reported to me, but not with sufficient positiveness to warrant 
regarding them as evidence. It seems, consequently, that it is a maladaptation 
that is not so very rare. 
In connection with the case observed by Henshaw the author makes a com- 
ment so interesting that it deserves quoting almost in full. We read: 
This apparently nonsensical departure from the acorn storing habit is by no 
means entirely devoid of significance, and forms an interesting example of a useful 
habit gone wrong. . . . California is remarkably well supplied with oaks, and the 
valleys, foothills, and mountains each have their own species. Nevertheless, not every 
year is an acorn year, and some seasons the supply of mast is very small indeed, or alto- 
gether wanting. It chanced that there was a very poor crop that year about Los Ala- 
mos, and, acorns being for the most part wanting, the birds took the readiest substitute. 
The storage habit, developed through thousands of years, has now become imperative, 
and, as the birds have to store something in the holes already suggestively prepared, 
they take the most convenient substitute, quite oblivious of the fact that the stones 
have no food value nor, indeed, any value whatever to the storer, except that arising 
from the pleasure of storing them. 
To say all that aches to be said of these remarks by Henshaw as a starter 
would require some long chapters in a large book. Indeed a book having as title 
‘‘The Natural History of Intelligence’’ has occupied nearly all my writing time 
for a year and bids fair to consume another year. This book might be character- 
ized as rotating upon an axis around the chief matters touched in the remarks. 
Obviously, then, discussion here of the points raised is out of the question. 
All I wish to do with reference to the subject is to make sure of not passing it by 
and thus giving the impression of being unconscious of its importance; and to 
eall attention to one difficulty presented by Henshaw’s very plausible, and, i 
believe, largely correct, explanation of the abortive performance by the wood: 
peckers. 
He assumes, you notice, that the pebbles are accepted as a substitute for 
acorns, their uselessness not being perceived at the time of storing. Now the 
question naturally arises as to why the birds should not discover the uselessness 
of the stones at the time of gathering them. Perhaps Henshaw’s idea is that the 
mistake is never discovered; but he is not explicit on this point. Surely, how- 
ever, the discovery would be made some time, for instance when, the next win- 
ter, the stored acorns or starvation should be the only alternatives before the 
birds. And that such a narrowing of alternatives may happen is made highly 
probable by the events of the very winter just passed. Snow to the depth of 
many inches, even feet, fell on three separate occasions over all home territories 
of these woodpeckers in southern California during the winter. And this snow 
remained on the ground for days on one of these occasions at Cuyamaca and 
was there accompanied by a layer of ice on much of the surface of the lake. 
To my very keen regret I was unable to visit Cuyamaca during the snow 
periods to see how it was faring with my birds. But there is little doubt that 
if the group I saw storing acorns last fall, or some other group, were there 
through the times of snow and ice, their lives depended largely if not wholly 
