PROTECTIVE RESEMBLANCE—HAAGNER. 501 
and would have seen it easily enough but for its assimilative colora- 
tion. When the bird settled again I immediately lost sight of it, 
and although it was only partially screened by the herbage I had to 
use my glasses to be sure of its identity. I took particular notice of 
this case, remembering Mr. Distant’s friendly criticism. That owls 
are subject to dimorphism is a well-known fact. Professor New- 
ton mentions it in his admirable Dictionary of Birds. This dimor- 
phism, not necessarily sexual, obtains in Bubo maculosus without a 
doubt. I have noticed a very fair degree of difference in the tints 
of the various birds that have come under my observation, and there 
are, or were, several specimens of this owl in the Pretoria Zoological 
Gardens which amply illustrate this fact. This, then, is a further 
proof of my contention that this species does possess protective 
resemblance. 
Order CoLuMB. 
The doves and pigeons afford another group of birds seemingly 
well endowed with assimilative coloring. 
With reference to the green wood pigeon (Vinago delaland?), Cap- 
tain Shelley has noticed the advantage this bird derives from its pro- 
tectively tinted plumage. Writing of this species in the eastern 
Cape Colony, Mrs. Barber says: “ The colors of the green wood 
pigeon of the Transkeian country so closely resemble those of the 
fruit and foliage of the wild fig (/icus sp.), their favorite fruit tree, 
that a flight of them may be concealed among its branches without 
being seen; on anyone approaching the tree, the birds being fully 
aware of the protection which their colors afford them, remain per- 
fectly motionless. A shot, however, fired into the tree will send them 
flying in all directions. The plumage of this pigeon consists of 
beautiful shades of green with red beak and legs; these colors blend 
admirably with those of the wild fig. The tree is an evergreen, and 
bears fruit all the year round, this continually affording the green 
wood pigeon not only food, but also protection, because it is the home 
of these birds.” 
I have repeatedly noticed how beautifully the slate and drab tints 
of the majority of our doves lend themselves to the concealment of the 
birds. This is so with regard to Zurtur capicola and T. senegalensis, 
and the fact is more worthy of notice in winter, when the mimosas 
have shed their leaves; the birds are even then most inconspicuous 
objects as they sit motionless among the naked branches and twigs. 
Writing of Haplopelia larvata (cinnamon dove), W. R. Ogilvie- 
Grant (in the Royal Natural History) says it is common in thick 
bush along the coast of Natal, where its brown coloring renders it 
difficult to detect as it sits motionless among the dense creepers. This 
is also applicable to the so-called bush dove or rock pigeon (Co- 
