190 THE BIRDS OF SHERWOOD FOREST. 
stream, or the wider expanse of lake or mere in which 
it takes its stand. The attitude in which it is generally 
seen is one of pensive quietude, for unless the observer 
is an early riser, or a watcher in the dim evening twi- 
light, he does not behold it in its more active moods. 
The island on the large sheet of water in Thoresby 
Park was long the resort of four or five pair of herons, 
who built their nests on the tall trees with which it is 
thickly covered. Here in the daytime some were gene- 
rally to be seen in watchful inactivity, sometimes standing 
in the shallow water a few yards from the bank, but 
more generally roosting on the trunk of a large silver 
willow, which, growing on the margin of the island, had 
given way and fallen until it lay at a slight inclination, 
or on the large projecting arm of another that grew close 
by. Though the island is a long way from the shore, 
and very far beyond the reach of a gun, they invariably 
took flight if any one stood on the mainland opposite ; 
and it was a pretty sight to watch them wheeling high 
in the air, or flying off to a wood on the further shore 
of the lake, where on the tops of the highest trees they. 
would perch to keep guard against their enemy. 
I have often approached to the edge of the shore 
under cover of the thick shrubs, and with a telescope 
have been delighted to watch their movements. It has 
surprised me to see that even those that appeared the 
most listless and unconcerned were extremely vigilant, 
their bright eye marking everything that moved around. 
Sometimes a mallard or a teal would come flying by, 
with a loud warning “quack,” when the herons would 
be on the gui vive in an instant, ready to take wing at 
the smallest sign that indicated danger. 
It is amusing to see them perch on the top of a tree; 
