Aviculturcil Notes for 1907 ,



63



edges to the outer webs of the external tail feathers. Of course

the difference in song continues. As I rejected some of these

characters on the ground that some of the deeper-coloured birds

possessed them, the question now arises as to whether, after all,

they may not be of importance. The change of colour from pale

to dark, certainly seems to render the validity of I. curasoensis as

a sub-species somewhat doubtful.


On the 27th I brought indoors the birds in my small out¬

door aviary, but left those in the larger aviary outside. Two hen

Weavers died during the year in consequence of damp and cold

fogs, but they were old birds which had been kept indoors for

many 3^ears.


On October 30th I received a pair of young Chingolo

Song-Sparrows, very kindly presented to me by their breeder,

Mr. W. E. Teschemaker.


The fact that reliance upon colour characters alone caused

me to sex incorrectly both a Bower Bird and Yellowish-finch,

clearl) 7 - evidences the importance of studying the external

structural differences in the sexes of birds. No doubt a com¬

parison of the beaks of undoubted sexes of Ptilonorhyuchits would

reveal differences of outline. In Sycalis arve?isis on the other

hand the beaks differ very slight^, not sufficiently to be of any

value in deciding the sex. A cock bird which I lost in 1905 is a

large and dull-coloured bird, but one which died in 1901 was

a trifle brighter, much smaller, and has the front margin of the

wing towards the shoulder bright yellow; the female which died

in July shows an indication of this yellow edging but is a

slightly larger bird than the cock and with more yellow on

abdomen and thighs; whereas the chin of the cock bird is

yellow, in the hen it shows an orange tinge. The large male

would be typical N. arvensis and the small brighter pair N. minor

only the male of the latter came home in an Argentine collection,

probably obtained at Buenos Ayres. Both of the smaller birds

have paler lower mandibles than the larger bird. I must confess

that, with the exception of luteiventris, in which the outer tail-

feather is obliquely marked with white, I have little faith in the

validity of the sub-species of S. arvensis , knowing as I do how

enormously S. flaveola varies in colouring at different ages.



