MIGRATION OF THE HERON. 335 
cares of incubation ; after the eggs are hatched, he also assists in 
providing for the young. 
~When the young Herons are able to fly, they leave the nest and 
cease to have their wants provided for by their parents. 
Fig 132.—Common Heron and Egret. 
About the beginning ot August the time for migration has arrived, 
the colony, possibly then amounting to 500 or 600 individuals, 
prepare themselves to quit the heronry. The following year they 
‘return, and their arrival, like their departure, takes place with great 
regularity of date. It is remarked that the number of couples 1s 
always nearly the same as that of the nests, so that each pair readily 
find a resting-place; the new generation must therefore leave their 
progenitors to found a fresh colony. 
