354 The Acorn-storing Habit of the California Woodpecker. [May, 



brush, as to escape detection. The length was not less than 175 

 feet, the diameter of the butt just above the ground, five feet ten 

 inches. At ninety feet the diameter was three feet eight inches. 

 Above the ninety foot line the holes continued, but were so scat- 

 tering that they are not included in the reckoning. Neither are 

 those in the first ten feet of the trunk, as between the ten foot 

 line and the ground they were comparatively few. 



Between the ten foot line and the ninety foot line the number 



: square 1 



ification, 



was from sixty to twelve. A piece of the bark, sawed from the 

 tree by my own hands, which measures exactly twelve inches by 

 twelve inches, contains sixty holes ; this is a much smaller num- 

 ber than could be counted in the same sized piece in a great part 

 of the section of eighty feet, while twelve is" a very low 



The two diameters as above given, when added make eight 

 feet and eighteen inches, the average diameter being one-half of 

 this, or about four feet nine inches ; this multiplied by three, to 

 get the circumference, gives fourteen feet and three inches ; and 

 this again multiplied by the length of the section, eighty feet, pro- 

 duces 1 140 square feet. 



Now if we add the maximum and minimum of acorn holes to 

 the square foot (sixty and twelve), we have seventy-two, which 

 divided by two, gives an average of thirty-six to the square foot, 

 and thirty-six times 1 140 gives a product of forty-one thousand 

 and forty (41,040) acorn holes. 



The holes are of different sizes, varying with the size of the 

 acorn, which each hole is made to receive, for these birds are 

 good workmen, and each acorn is nicely fitted into its special 

 cavity. Making a fair selection of acorns as to size, I find that, it 

 takes on an average seven to make an ounce (that is, picked when 

 green) ; and taking that number for a divisor, it shows the total 

 weight of acorns required to fill the holes in the tree, is three 

 hundred and sixty-six pounds seven ounces, avoirdupois. Whether 

 any particular species of acorn is preferred, I am unable to say. 

 The acorns in the tree above described, so far as it was possible 

 to determine them without the cups, which the woodpeckers 

 reject, appeared to belong to the nearest adjacent oaks, Quercus 

 chrysolepis. This oak is very abundant all around the mountain 

 and is itself peculiar in having two forms of leaf on the same twig- 



