112 RUDOLF SÖDERBERG, STUDIES OF THE BIRDS IN NORTH WEST AUSTRALIA 
the ends of the tunnel quantities of vertebrae and bones of kangaroos, shells, 
stones, big seeds and fruits had been collected, and at the sides there were a 
great number of pieces of charcoal, taken from camp-fires. The »toys» placed inside 
were evidently specially chosen from those heeps and were distinguished by being 
more equal both in form and size. (Plate 4, fig. 3 and 4). 
The pieces of charcoal were remarkably numerous which is strange, in as much 
as no conspicuous colour is present here. They were lying in a circle round the 
other objects. It seems most probable to me that the birds had come to the de- 
serted camps, and observing the yet glistering charcoals been tempted to collect such 
slightly shinning things. Black things did not else occur among the collected materials. 
In Meda I found another of these »play-grounds»>, put up in quite the same 
way, but much smaller and more thinly constructed. It is probable that the bird 
continues to build and improve its play-ground and keeps it from year to year. 
In March, April and May, all the months, during wich I had a chance to ob- 
serve the play-ground, I have not seen the birds playing at them, but they were 
living in the neighbourhood and visited them now and then. The bird was shy, 
and I noticed, that at the play-houses it was still more invisible and difficult to 
approach than on other occasions. Sometimes three or four birds were seen flying 
from the play-ground. 
The white men told me that the bird often stole small things, such as pipes, 
knives, etc. at their camps; that is why they called it »the stealing-bird»>. But the 
black men found that the play of the bird reminded them of their »corroborro»-dance, 
and to them it was therefore the »corroborro-bird». The impression I got was that, 
when the natives saw the bird carrying twigs and splinters, they imagined that it 
was dancing just as they did themselves armed with spears, boomerangs, etc. 
At Sunday Island the bird lived in the precipitous mountain-walls among stones 
and blocks. Its note is harsh. In Derby specimens, that had been opened, had eaten 
masses of the small fruits that at this place were called »native-figs». I often saw 
them seek out such trees, and I think that this was the reason the birds came into 
the village, as this tree does not grow everywhere. In the evening they flew to- 
wards the bush again. 
Fam. Corvidee. 
Corvus coronoide cacile MATH. 
Math. handl. n:r 872. 2 SS ad., 2 ad. Nooncanbah, Fitzroy r. 5/12 1910, 3/1, S/+ 1911, all; moult. 
Q 
tail only); I ad., 2.22 ad. Beagle bay, Dampier 1. 5/7, "/1, !!/7 1911, worn dress. 
Ecological. — The crow was common in all the places, visited by the ex- 
pedition, except Sunday Island, where it was missing. It appeared in flocks of a 
hundred or more and often kept company with the kites. When the expedition had 
encamped, big flocks of them often collected around us, only waiting for our depar- 
ture so as to devour the remains of our meals. In some places the bird was not 
seen. It evidently strayed about far and wide in the winter months. 
