68 Correspondence. 



last issue of Bird Notks ; especially in what you say about inbreeding. I 

 wonder if it would make any difference u the birds are kept in a large wilder- 

 ness aviary, almost as if they were at liijerty. I believe it is the rule with 

 wild birds for brothers to mate with sisters : and this must have gone on for 

 many generations ; and yet the wild bird does not seem to get weaker in 

 constitution. I have a fairly large aviary of canaries, out of doors. I put 

 out two i)airs in it in 191J: now there are about lift\- ; I have never introduced 

 any fresh blood, and yet every year the young seem as healthy as ever. 

 Now they build nests as good as any wild linnet, and are as vigorous and 

 strong as any wild bird about the garden. There is not the least deterioration 

 even though many of them are crested. In cages one knows that inbreeding 

 must be avoided, especially with crested birds, but it does not apj)ear to 

 make an)- difference in a large aviary. I am wonder'ng if Budgerigars were 

 kept in a large aviary if in-breeding would be as injurious as u appears to l)e 

 Sturminster Newton. March 16, 1922. R. E. P. GOKRlNGK. 



[My opinion is (I am open to correction) that it is the exception and 

 not the rule for brother and sister to mate together in a state of liberty ; their 

 general habits almost preclude this. 



Most, if not all, the Psittacidae pair for life in their wild state, but 

 with many other Families this is not the case, and many have a fresh mate 

 every season. 



I have made man\' experiments in the jjast with Budgerigars and some 

 passerine species, and have found that never of their ozvn choice zvill brother 

 dud sister mate; and, from t!ie basis of that experience- I doubt if Mr. 

 (iorringe's canaries so mated. 



Put two pairs of the same species into an aviary, ring the progenx 

 of the respective pairs with different coloured rings, and, I think 

 (writing from the results of my own experiments), it will be found that onl . 

 under compulsion do brother and sister mate. 



Again and again it has turned out that when a single pair of Zebra 

 h'inches (Taeniopygia castonotis) is j^ut into an av'ary. all their progeny 

 retained, but no new stock introduced, that in a comp;iratively few years 

 every Zebra Finch will have died out. 



My experience teaches me that regulated judicious in-breeding improves 

 stock, but that, unregulated promiscous in-breeding has the reserve effect. 

 I shall, however, welcome the exjjcrience of other members. — W. T. P.vc.i:. ; 



MY BLACK-CAP LORIES (LORIUS LORY). 



Sir, — As I see you put a note in November I5ird Notes about my 

 Black-caps' eggs, I may say she sat well as usual, but I believe the egg got 

 chilled owing to workmen in the aviar\- disturbing the hen ; anyway, the 

 egg failed to hatch though it contained a perfectly formed chick. Thus 

 (iurii. 1921 this p-'''r of birds laid foiu" eggs, two of which got broken, one 

 conta ned a dead ciiick as above, and one hatched out, and the young bir 1 

 is now seven months old. The hen is now very busy carrying every splinter 

 of w. id she can find into the nest, and evidently is about to lav again. 



Their seven months' old baby is a lovely strong bird, perfectly feathered, 

 btit does not yet possess the brilliant red plumage of his parents. He can 



