q8 BIRD STUDIES WITH A CAMERA 
the froglike monotone of the young is broken by 
the sudden quawks of their parents. 
The rookery is in a low part of the woods which 
evidently is flooded early in the year, a fact which 
may have influenced the Herons in their selection 
of the locality as a nesting site. At the time of 
our visit the swamp maples, in which the nests are 
placed, were densely undergrown with ferns, and 
as we approached the whitened vegetation, which 
clearly marked the limits of the rookery, a number 
of Herons with squawks of alarm left the vicinity 
of their nests, and soon the rookery was in an up- 
roar. The common quawk note was often heard, 
but many of the calls were distinctly galline in 
character and conveyed the impression that we had 
invaded a henroost. 
The trees in which the nests were placed are very 
tall and slender, mere poles some of them, with a 
single nest where the branches fork; while those 
more heavily limbed had four, five,** and even six of 
the platforms of sticks, which with Herons serve as 
nests, but in only a single instance was one nest 
placed directly below another. A conservative count 
yielded a total of five hundred and twenty-five nests, 
all within a circle about one hundred yards in diam- 
eter, nearly every suitable tree holding one or more, 
the lowest being about thirty feet from the ground, 
the highest at least eighty feet above it. 
While the limy deposits and partially digested 
fish dropped by the birds seemed not to affect the 
growth of the lower vegetation, it had a marked 
influence on certain of the swamp maples, the devel- 
opment of the trees which held a number of nests 
