24 
HINTS ON CAGE-BIRDS. 
Group or Java Sparrows. 
whether or no this is a fact, I am not botanist enough to say ; one 
thing, however, is certain, that food eaten freely by birds when at 
liberty sometimes makes them seriously ill when the same birds are 
confined even in a fairly large aviary ; for this reason I would never 
offer ivy berries, though I believe that elderberries and haws are 
quite wholesome. Among seeds which are freely used by many 
keepers of British birds are several which I formerly gave as 
a matter of course. 1 found, nevertheless, that 1 lost many birds 
in my aviaries, either from diarrhoea or excess of fat, and 1 thought 
for some time that hemp was the cause of t he mortality. I gave no 
hemp for a time, but still the death rate remained high ; therefore 
I removed other seeds, replacing the hemp as before. By thus 
experimenting I discovered that flax, inga, and black rape were at 
the bottom of all the mischief ; for t his reason I always warn 
aviculturists against the use of these seeds. Flax is a favourite 
food with some Finches when wild, but I am sure it does not suit 
them in captivity. 
Of the nuts most useful for bird food I think walnuts and 
Barcelonas are the best ; Brazil nuts are too oily, and monkey nuts 
are always rejected in favour of crack-nuts. ' A reader of Tie 
Feathered World took a great deal of trouble recently to obtain palm 
nuts, because 1 had mentioned them as one of t he foods of the Grey 
Parrot when at liberty ; she very kindly sent me some samples of 
palm kernels, black-looking things shaped like chocolate creams. 
1 confess I had not the courage to offer them to my bird. For an 
aviary of Tits a suspended cocoanut, with a piece sawn off, so that 
the birds can get at the nut, is very useful ; if you hang one up in 
your gat den in the winter you will soon see the Tits at work upon it. 
Now, to come down to special foods for special birds. As 
