TQiO. 



Moffat. — Colours of Birds. 



30 



else 1 can tliink of, unless 1 fall back on Mr. Ussher's 

 comparison, and say it is like a bit of the fir-bark. 



Passing from protective (or, perhaps, I should say, 

 " self protective ") plumage, we come to plumage more 

 clearly adapted for display — or, as it sometimes might be 

 called, " protect-your-neighbour " plumage. Display may 

 be for signalling purposes, though the more interesting case 

 of ornamental plumage remains to be noticed later. From 

 one' of the most usual modes of signalling among birds I 

 think we must derive our familiar phrase " to show the 

 white feather." The white-feather patch above the tail 

 which so many birds possess serves as an excellent alarm 

 signal to all the owner's companions whenever the owner 

 takes flight. Familiar instances of birds showing this 

 signal are the Bullfinch, Brambling, Wheatear, Jay, and 

 Rock-Dove. The Chaffinch conveys a similar message 

 with the outstretched white feathers of its wings (a. feature 

 that gives this bird in Co. Wexford the local jiame of the 

 White- wing), and the Hawfinch on taking flight shows to 

 a like purpose the white of its outspread tail. The same 

 principle is followed in other cases, in which the signal is 

 sometimes not white but orange or yellow. 



I may be asked " Is there any proved connection between 

 these signals and the habits of the birds that use them ? " 

 If a bird has a white patch across its back the white will 

 show w^hen the bird flies ; but if it has no such patch it 

 will fly all the same, so what have its habits to say to the 

 question ? Well, I think there is generally some reason' 

 in the habits of a bird to explain its having, or not 

 having, this means of signalling danger to its comrades. 

 There are, for instance, some birds so unsociable that 

 they never (except in the pairing season) have any 

 companions to signal danger to ; among which I will 

 specially mention the Robin, whose plumage, when he 

 flies, shows not a particle of a signal-flash. Then some 

 birds consort together in such strongly organised bodies 

 (like the Starling) that the rising of one of them can't fail 

 to be perceived by his neighbours, and the whole flock 

 rises by telegraph. Others make such a noise (as the 

 Wood-pigeons with its wings or the Plover with its "shrilly 



A 7. 



