KUNGL. SV. VET. AKADEMIENS. HANDLINGAR. BAND 52. N:O |7. 17 
B. The birds. 
Geographical features. 
The bird-world generally contributes much more than the other divisions 
of the animal world to the main features, that give the landscape its character. As 
to North West Australia that fact here is specially cbnspicuous in consequence of the 
uniformity of the mammalian fauna. Marsupials are nocturnal animals, and on ac- 
count of that they practically lose the importance for the landscape that birds 
generally have. 
In the open savanna-woods of Kimberley, where flocks of birds were seen during 
by far the greater part of the year (cf. below), the birds play an important role in 
relieving the lifelessness and want of colour of the landscape, which but for them 
would recall the desert. 
Few parts of the world have such brightly plumaged parrots as Australia, and 
together with the cockatoos, they were the characteristic birds even in Western 
Australia, thanks to their lack of shyness and their general occurrence. It is, however, 
only on very well-defined districts that the bird-life is of such importance. Only at 
the rivers and the scattered water-pools does the wood lose its opressive uniformity 
thanks to the presence of birds. In this connection we see that there is one special 
condition that, both as regards numbers and varieties, is of great influence, and that 
is the wandering proclivities of the birds. Their periodical appearances cause discon- 
tinuous distribution, which may be said to be a geographical characteristic of the bird 
fauna of these regions. 
It is natural, too, that the great monotony of the natural features of the 
country must favour such wanderings. But they are inevitable on account of 
two circumstances: the want of water (the drying of the water courses and water 
pools during 6—8 weeks after the end of the rainy season) and variable and indi- 
vidual flowering-times of the Eucalyptus-trees, on which they chiefly feed. 
In the winter time a great number of birds thus withdraw to the very few 
and scattered water-places, if the species does not simply migrate from its breeding- 
place. In these flittings one consequently. traces habits which in greater or lesser 
degree resemble those of the migratory birds as well as those of the wandering-birds 
in the northern hemisphere. As may be seen this is not here due to important tempera- 
ture-intervals between the seasons and their corresponding changes. Another climatic 
factor, the torridness, which for the greater part of the year makes untenantable for 
birds great stretches of Kimberley, has instead caused these movings. For certain 
species, as has been said above, also the absence or presence oi food, viz. the flowers, 
causes strayings and wanderings. 
On my return to Derby in March, 1911, I got an opportunity to observe how 
the bird-life changes at the approach of winter even at the coast. Some species had 
been common which before were only few in numbers while others were gone away 
and so to say replaced by new species. To the latter belonged grass-parakeets, which 
E. Sv. Vet. Akad. Handl. Band 52. N:o 17. 3 
