1875.] MR. W. H. HUDSON ON THE HABITS OF HERONS. 629 
in several months, built two false nests on the water, ten or twelve 
yards from the shore. 
It is worthy of notice that the Myopotamus coypus has a similar 
habit. The Coypus make great burrows in the banks of the water- 
courses they inhabit, but appear to use them, at least where there are 
reeds, only as a refuge from danger and to bring forth their young in ; 
for they also build platforms of reeds and pass the day lying on them. 
In some watercourses in Patagonia the Coypu (and it is there a third 
larger than the variety found on the pampas) has quite dropped the 
burrowing habit, doubtless on account of the sand and gravel soil, 
and lives entirely amongst the reeds, the female bringing forth her 
young on the reed platforms or nests. 
I will give a fuller account of the little Variegated Heron, Ardetta 
involucris (Vieill.)*, and particularly of its instinct of self-preser- 
vation. 
The Variegated Heron isa silent solitary bird, frequents the marshy 
borders of the Plata, and is occasionally found in the reed-beds scat- 
tered over the pampas. It breeds amongst the close-growing rushes, 
and lays three spherical eggs of a rich lively green and beautiful beyond 
comparison. 
The nest is a simple platform structure several inches above the 
water, and so very small that there hardly seems room enough on it 
for the eggs, which are very large for the bird. When one looks 
down upon them, they cover and almost hide the nest from view, 
and, furthermore, being green like the surrounding rushes, are not 
easy to discover. 
When driven from its haunt, the bird flies eighty or a hundred 
yards off, and drops again amongst the rushes ; it is difficult to flush 
it a second time, but a third impossible. And a very curious cir- 
cumstance is that it also seems quite impossible to find the bird in 
the spot where it finally settles. Being found in places where one 
can only enter on horseback, I could never succeed in shooting spe- 
cimens when I wanted them, and was obliged to employ some Gancho 
boys, who had dogs trained to hunt young ducks, to try for the little 
Heron. They procured me a few specimens, and told me that, 
without the aid of their dogs, they could never succeed in finding the 
bird, though they always marked the exact spot where it alighted. 
This I attributed to the slender figure it makes, and to the colour of 
the plumage so closely resembling that of the withering yellow and 
spotted reeds always to be found amongst the green ones; but I 
did not know for many years that the bird possessed a marvellous 
* In a paper by Messrs. Sclater and Salvin on Buenos-Ayres birds, published 
in the Society’s ‘ Proceedings’ (1869, p. 634), Ardetta erythromelas is given as 
a synonym of A. zavolucris; but it is added:—‘ We are, however, inclined to 
doubt very much whether this is really the young of A. erythromelas, as referred 
by Bonaparte, Burmeister, and other authors, and prefer waiting for other 
examples before arriving at a definite conclusion on this point.” Closely as the 
two birds are related in form and colour, the difference in size might well induce 
a doubt as to their being merely the young and adults of one species. In Buenos 
Ayres A. involueris is not uncommon, but I have never met with A. erythromelas, 
nor do I believe it ranges so far south. 
