110 THE CONDOR Vol. XXIII 
toil. The majority of them, indeed, lead a ‘‘hand to mouth’’ existence and 
spend most of their waking hours in the never ending quest for sustenance 
for themselves and their offspring. In the cold and temperate zones, when the 
food supply begins to fail, most of them depart for regions where food is 
plenty and never failing. In their constant struggle for life their wings confer 
upon birds a great advantage over their less mobile cousins, and it is of inter- 
est to note that the bats, the only family of mammals that has developed the 
power of flight to the point that vies with birds, has also adopted the habit of 
migration, and, with rare exceptions, the several species leave the colder re- 
gions for more tropical ones. 
The most conspicuous example among birds of a food storer is the Cali- 
fornia Woodpecker, under which name for the purposes of this paper are in- 
cluded the ‘‘ Ant-eating Woodpecker’’ of our southern border and Mexico, and 
the ‘‘Narrow-fronted Woodpecker’’ of Lower California. All these are but 
subspecies of Melanerpes formicworus. 
In early November of 1884, while conducting linguistic researches among 
the California Indians, I visited the town of Los Alamos, having found there 
an old Indian who formerly lived on Santa Rosa Island, and who was one of 
the last survivors of his tribe, if not the last. My daily walks morning and 
afternoon to where he lived on the outskirts of the town carried me through 
a grove of scattered oaks, and here I had an excellent, though brief, oppor- 
tunity to observe a colony of woodpeckers storing away acorns in holes already 
drilled in the dead branches of the oaks. 
Here for the first and only time I saw the birds pick up pebbles from the 
eround, and insert them in the holes as a substitute for acorns. This appar- 
ently nonsensical departure from the acorn storing habit is by no means en- 
tirely devoid of significance, and forms an interesting example of a useful 
habit gone wrong. The explanation of the substitution of pebbles for acorns 
seemed to me at the time to be simple enough; nor do I see any present reascn 
to change my view. 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 altogether wanting. It chanced that there was a very poor 
crop that year about Los Alamos, and, acorns being for the most part want- 
ing, 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, which will be adverted-to later. Probably 
not many stones are thus laid away as compared to the number of acorns, but, 
as the birds have no further interest in them, they remain where placed tili 
in the lapse of years they weather out and fall to the ground. 
The practice of storing stones in the holes dug for the reception of acorns 
is by no means a local one. Other observers, as quoted by Dr. Ritter, have 
noted the habit in widely separated localities, both in our own territory and 
Mexico. Thus C. R. Oreutt contributed to Science of March 14, 1884, a note 
stating that 75 miles south of the boundary, in Mexico, at an altitude of 6000 
feet, he observed ‘‘the bark of pines perforated with holes’’ in about one-third 
