A Floating Terns’ Colony 99 
peculiarly deep and dangerous but are seldom so. It is a curious 
sensation wading alone along these water-lanes with the high 
rushes cutting off one’s view of the land on all sides. Sometimes, 
when moving quietly in such a spot, I have heard Bitterns calling 
in the dense reeds close by or been startled by the curious cry of 
the big Purple Gallinule (Porphyrio cwruleus), These beautifully 
coloured but ungainly birds at times rise at your feet and, flapping 
away for a few yards, subside into the reeds again. Once I came 
round a corner almost face to face with a Great Crested Grebe. 
The fine Great Reed Warbler (Acrocephalus turdotdes), which 
builds a most artistic nest suspended amid the bulrush, breeds 
in this marsh and its powerful song can be often heard at close 
quarters. 
In the more open parts of the laguna, away from the high reeds 
and where the whole surface of the water is whitened by the flower- 
ing ranunculus, the Whiskered Terns ({/ydrochelidon hybrida) con- 
struct their floating nests of loosely knitted green reeds. Some of 
these flimsy platforms are held by their surroundings and are thus 
lightly moored, but others again are attached to nothing and drift 
with the wind. Thus one year in May I came upon several score 
of nests scattered about among the young reeds and upon revisiting 
the place a few days later found that the majority of them had been 
blown by the wind to the lee-side of the laguna, where they were 
packed in a dense mass. Three is the usual complement of eggs 
laid, of a delicate green ground-colour, richly blotched and spotted 
with black and brown. The old birds are singularly beautiful on 
the wing, their dark breasts appearing in the brilliant sunlight to be 
quite black and contrasting with their silvery grey backs and wings. 
So long as you are in the neighbourhood of one of their lake 
dwellings they keep up a great commotion and_ indulge in voci- 
ferous cries. Now and again a villainous Marsh Harrier intent on 
egg-stealing comes flapping and skimming along near the Terns’ 
