2I8 
NATURAL HISTORY QUERIES. 
64. Longevity of Wild Birds. — I should be much obliged if any one 
could refer me to a book or article in which information on this subject could 
be got. I should like to test the validity of conclusions to which I have been led 
on this point. If the following assumptions be made, viz., that a particular 
species of birds breed when one year old, and that on an average they bring up 
safely one pair of young for each pair of parent birds, and that the average length 
of life of the birds was eighteen months, then their numbers would neither 
increase nor diminish. If they brought safely up four young on an average, 
the other assumptions remaining the same, then when the second year came the 
parents would be dead, but two pairs of young would be in their place; the 
third year this second generation would be dead, but four pairs would have 
succeeded them; and so on in geometrical progression, so that when an 
equilibrium in numbers was attained the average length of life would be far 
less than eighteen months in order to maintain this equilibrium. The lives of 
cage-birds show that it would not be of old age that they would die, e.vcept in 
rare cases, and birds of prey are so ruthlessly kept down that they would not 
account for many deaths ; so that in the vast majority of cases the birds would 
die a painful and lingering death from starvation or cold within eighteen months 
from their births or a much shorter period if, on an average, they bring up more 
than two young annually. In the case of birds that soon make themselves at 
home in cages, such as siskins, bullfinches, &c., I cannot doubt that if it 
were possible to give them their choice, they would prefer a comparatively long 
life in a cage, with abundance of food and shelter and the companionship of man, 
which they evidently enjoy, to the early and painful death, which would in most 
cases be their lot if left in a wild state, supposing my assumptions and the 
reasoning founded on them be correct. 
Keith, Banffshire. Ale.X. Thurburn. 
SELBORNE SOCIETY NOTICES. 
[Note. — All Announcements with regard to Future Meetings of 
THE Central Society or Branches will be found together at the 
END OF these NOTICES.] 
Objects of the Society. — To promote the study of Natural History. To 
preserve from needless destruction such wild animals and plants as are harmless, 
beautiful, or rare. To discourage the wearing and use for ornament of: (l) The 
skins and furs of such animals as are in danger of being exterminated ; ( 2 ) the 
skins and plumage of such birds as ate not domesticated. To protect places 
and objects of natural beauty or antiquarian interest from ill-treatment or 
destruction. To afford facilities for combined effort in promoting any of the 
above or kindred objects. 
New Members. — Cailra/ Society. — Mrs. Briggs, Cheshire ; C. W. Cooke, 
Esq., F.R.H.S., Walham Green ; J. II. Nelson Curtis, Esq., Sutton ; Cecil 
Davis, Esq., Wandsworth ; Miss Kate .M. Hall, .Stepney Borough Museum ; 
Peter Lawson, Esq., P'.R.M.S., L.C.C., Fulham ; Richard Lewis, Esq., 
P'.R.M.S., Ealing; Major H. E. Poole, V.D., Willesden Green ; Edmund 
Witheridge, E.st)., Kingston Hill; Frederick Winkfield, Esq., P'ulham ; Miss 
Laura Yates, Hamilton Terrace, 
Birmingham Branch. — William Francis Wiemann, Esq., Erdington. 
Croydon Branch. — Miss M. Latham and Miss 1). Latham, Croydon. 
Hampstead Branch. — Mrs. Hatley, Hampstead ; Leonard II. Roberts, Esq., 
Willesden Lane. 
