Cambridge Mass. 
ydr/c 
any possibility of mistake that it ate small pieces of the mortar. 1 
was very sure that my bird was doing the same thing (on the I4th). 
' 
It would be interesting to know whether the mortar is eaten for the 
sake of the lime it contains or as a substitute for gravel which may 
. 
be rather difficult to obtain now that the ground is largely covered 
with snow. 
I noticed this morning that quantities of fresh earth 
had been thrown out from between the stone flags in the walk in front 
' 
of the Museum in our garden and I wondered what could have done it. 
a KJu Jl— 
^LcxXCt*- 
CtSViJH/ 
The mystery was quickly explained for early in the afternoon I saw a 
Flicker busily engaged at the walk. Hopping slowly along sideways on 
the flags he made a dozen or more holes while I was watching him in 
the earth between them. Iu was packed hard on the surface and he had 
to peck vigorously at first to make any impression it. The cracks 
were narrow (not more than l/4 inch wide) in places and more than oncg_ 
he missed his aim and struck his bill forcibly against the edge of a 
stone making an audible sound. After making these holes he visited 
and revisited them and others which he had made previously spending 
some time at each of them and extracted from some of them a quantity 
of food which I could see him swallow although I could not make out 
