16 
The N.Z. Journal of Science and Technology. 
[Jan. 
NOTES ON THE ACCLIMATIZATION OF BIRDS. 
By Dr. Rudolf Haeusler, 
This Journal lias done a service to New Zealand in drawing attention once 
more to the important subjects of the acclimatization and control of birds, 
and in opening its columns to discussions on these matters.* In this article 
I have to offer a few remarks on the two groups of European birds which 
Mr. H. W. Simmonds specially mentions as worthy of acclimatization in this 
country—viz., the titmice and the woodpeckers. These remarks are based 
upon many years' close observations in Switzerland, my native country, and 
in other parts of the Continent, but they refer to species which have a 
very wide range of distribution, including the British Isles. 
The first-named, the titmice, Mr. Simmonds describes as being “ amongst 
the most beautiful and useful groups of purely insectivorous birds.” On 
the question of the usefulness of these birds there cannot, of course, be any 
doubt whatever. Their sphere of action is, it is true, somewhat limited, 
being—except in the case of the bearded tit, whose habitat is the reed- 
covered marshes—almost entirely restricted to trees, bushes, and low scrub. 
In these haunts, however, they render invaluable services, as their extra¬ 
ordinary agility, ceaseless activity, keen vision, and intelligence enable 
them to discover even the minutest insects, and their eggs, larvae, and 
pupae, in their most carefully chosen hiding-places. 
With the exception of the already mentioned bearded tit and of the 
crested tit, which is seldom found outside the great pine forests, titmice 
are frequently met with in the close vicinity of human habitations. The 
great tit and the blue tit especially show a decided preference for such 
localities, and will, if hollow trees or other suitable building-places exist, 
or if nesting-boxes are provided, make their permanent home in gardens 
and orchards, where they become so friendly that they will take food, 
kernels of walnuts, and other titbits from the outstretched hand whenever 
they are called to do so. 
The amount of good these birds do under these circumstances is seldom 
fully appreciated. The fact that in one year a single tit may destroy as 
many as 300,000 insects, most of them belonging to injurious species, helps 
to give a fair idea of the greatness of their services to man. 
Tits are, of course, most active at the time when they rear their 
amazingly large families, which event happens twice in the one season. 
The number of insects which the parent birds have to provide to fill eight 
to twelve and in some cases even more ever-hungry little stomachs, in 
addition to what they require for their own wants, must almost pass 
belief. The title of “ guardians of the orchard ” which has been given 
to these birds on the Continent is therefore fully justified. 
So far so good. There is, however, another side to the question, which 
in a discussion bearing on the subject of acclimatization demands very 
careful consideration. Titmice are, as a matter of fact, not purely insect¬ 
ivorous. Their diet is, on the contrary, very mixed, and includes such 
things as seeds, nuts, berries, and other fruits, and this not only in winter, 
* CJ. W. E. Collinge, The Food of British Wild Birds, vol. I, pp. 67-69; H- W. 
Simmonds, Suggestions for Acclimatization of Animals in New Zealand, vol. 1 
pp. 132-34; and subsequent correspondence. 
