46 MENTAL DEVELOPMENT IN ANIMALS 
or a stone, or beside a fallen branch until he has gone by. 
On one occasion a blackboy, who accompanied my stock- 
man in his rounds, cut down three with his stockwhip 
out of a group of eight. Many squatter pigeons lose their 
lives in this way, through their too great confidence. 
The morpork (podargus), of which we have several 
varieties, and of which I exhibit a specimen, forms another 
marked example. The colour of the bird’s plumage and 
its markings, resembling as they do the dry bark of some 
of our eucalypts, would, one would think, afford a large 
amount of protection: but added to this is the conscious 
mimicry which prompts the bird to place itself in such 
a position that only an observant passer-by would see 
it. Even the bush curlew, or stone plover (adicnemus 
grallarius) will posture in such a manner that it may 
easily be taken for a stump or part of a fallen branch. 
I will now call attention to a different form of mimicry 
which birds have recourse to. I mean the building of 
their nests. Passing by the clever arrangements of stick 
or grass as one of minor interest, I may refer to the mud 
nests of the common house swallow (hirundo neoz:ena). 
These they love to build up in our verandas, where they 
sometimes become a great nuisance. In such positions 
they are easily seen ; but once there were no houses, and 
then the birds had to look for a hollow in an old tree or in 
a log; sometimes they build their nests under over- 
hanging rocks, or on the side of a rough-barked tree. In 
unfrequented localities these may still be found, and it is 
obvious that the leading thought of the builders has been 
the concealment of their temporary home. 
A yet more remarkable evidence of thought is the 
playground of certain of our native birds. Many of these 
are simple structures, made of twigs, placed in an almost 
upright position, and between too such rough fences the 
birds amuse themselves by running backwards and forwards. 
A much more striking one is that which some years ago 
was found on the Bellenden Ker Mountain ; it is sometimes 
called after (Mr. Archibald Meston,) Meston’s Bowerbird 
(priondura newtoniana). I understand that Broadbent, 
of the Museum, first brought it under notice. In this 
case, as will be seen by the illustration, the first business 
