The Cliff Swallows 
are composed of pellets of mud deposited in successive beakfuls by 
the industrious birds. It is always interesting to see a twittering com¬ 
pany of these little masons gathering by the water’s edge and moulding 
their mortar to the required consistency. Every wing is a-flutter, and 
so seething is the com¬ 
motion that no camera 
can do justice to the 
scene. Not less inter¬ 
esting is it to watch 
them lay the foun¬ 
dations upon some 
smooth rock facet. 
Their tiny beaks must 
serve for hods and trow¬ 
els, and because the first 
course of mud masonry 
is the most particular, 
they alternately cling 
and flutter, as with 
many prods and fairy 
thumps they force the 
putty-like material to 
lay hold of the i n - 
different wall. 
There is usually much 
passing to and fro in 
the case of these cliff- 
dwellers, and we can 
never hope to steal upon 
them unawares. When 
one approaches from be¬ 
low, an alarm is sounded, 
and anxious heads, wear¬ 
ing a white frown, are 
first thrust out at the 
mouths of the bottles, 
and then the 3.ir becomes Taken in the San Bernardino Mountains Photo by Wright M. Pierce 
filled with flying swal- A n unusual nesting site—yellow pine at bear lake 
lows, charging about the 
head of the intruder in bewildering mazes, and raising a babble of strange 
frangible cries, as though a thousand sets of toy dishes were being broken. 
If the newcomer appears harmless, the birds return to their eggs by ones 
5-7 
