March, 1953 
THE SOUTH AUSTRALIAN NATURALIST 
Thirty-five 
PLANT DISTRIBUTION BY BIRDS 
Before the European colonisa- 
tion of Australia, its animals (in- 
cluding man) and plants had 
reached more or less an ecological 
equilibrium. Doubtless this equili- 
brium oscillated at times over 
many thousands of years and major 
By ]. B. CLELAND < x ) 
changes must have taken place 
during glacial and torrid periods. 
With the white man came destruc- 
tion of native trees and shrubs to 
be replaced by crops and pastures, 
the introduction of farm animals, 
the accidental conveyance from 
other parts of the world of aggres- 
sive weeds, and the lamentable 
activity of acclimatisation societies 
who set free sparrows, starlings, 
blackbirds, English thrushes, gold- 
finches and so on. It is of interest 
to consider to what extent our 
native birds have been able to 
utilise the introduced plants as 
food, and on the other hand which 
of the introduced birds have found 
suitable native food-plants. Are 
the alien birds distributing almost 
entirely alien plants or have they 
aided in disseminating native 
ones? 
Native Birds Utilizing Introduced 
Plant Foods 
Good examples are parrots and 
silver-eyes in orchards, white cocka- 
toos in fields of grain, galahs and 
germinating grain, and the emu 
and prickly pear. Of these, only 
the emu is acting as a disseminator 
of the seeds of its food-plant. 
Introduced Birds and Native Fruits 
and Grains 
In South Australia, edible native 
fruits are few in number. They 
comprise the following:— 
Liliaceae : — RidleyP* says that 
Dianella, of which we have two 
species with blue berries, is a genus 
“which is far more widely spread 
and common than any of the sec- 
tion to which it belongs. The head- 
quarters of the genus is Australia, 
where are a number of species, 
whence it has radiated to many 
islands, Polynesia, Fiji. . . . There 
can be little doubt that these widely 
distributed plants owe their success 
to the conversion of the capsular 
fruit into a conspicuous berry, 
allowing of their dispersal by 
birds.” I do not know of any 
observations showing that the 
fruits of our species are eaten by 
birds. 
Santalaceae Our four species 
of Exocarpus (Native Cherry) and 
Leptomeria aphylla, sometimes 
called Native Currant, have edible 
fruits but I am unaware of birds 
feeding upon these. The Quan- 
dong or Native Peach ( Eucarya 
acuminata) is widely distributed, a 
fact of significance perhaps in con- 
nection with our subject. The 
Bitter Quandong (E. Murray ana) 
is similarly widely distributed. San- 
ta lum lance ol at inn and its variety 
augustifolium in our Far North 
has a dark blue plum-like fruit. 
Loranthaceae:— The Mistletoes 
are dealt with more fully later 
on. J doubt whether any of the 
introduced species feed upon its 
fruits. The Blackbird would be 
the most likely, but would not 
favour the altitude without cover 
of most of these parasites. Osborn 
(U Vide the S.A. Ornithologist Vol. XX., part 
7, pp. 72-77, for a further article on this 
subject; (part of which is reproduced with 
further original observations. — Editor). 
( 2 ) Ridley, H. N. "The Dispersal of Plants 
Throughout the World," 1930. 
