266



Notices of A T ezv Books.



a record of all escaped birds throughout the British Isles to see

how mail}'’ of them had assisted (presumably) in swelling the

records of rare visitors to our coasts.


On page 30 is a photograph of the nest and eggs of the

Short-eared Owl found breeding at Rainworth, Notts., on May

1st, and various other notes of interest complete the number.


Ed. pro tern.



Preliminary Report on an Investigation of the seasonal changes

of Color in Birds. By C. William Beebe. The American

Naturalist, vol. XLII., No. 493, Jan. 1906.


The experiments of Mr. Beebe are all extremelyinteresting,

and that described in the article forwarded to us is especially so :

it deals with the cause and factors which determine the seasonal

change in the males of the Scarlet Tanager (of North America)

and the Bobolink.


Mr. Beebe first suggests seven possible factors which may

influence this change of color ; but, the experiment which he

describes (and which had the remarkable result of completely

eliminating the autumn moult, so that the bird, in the spring,

moulted from nuptial plumage to nuptial plumage—the green

winter plumage being skipped) only dealt with the “general

condition of the bird’s body—whether fat or lean.”


The selected birds were not allowed to breed ; the supply

of light was gradually cut off, aud the amount of food increased ;

as obesity in caged birds renders any excitement or sudden fright

liable to cause apoplexy, the birds were kept in a room in which

they were never disturbed and where there was no noise : they

took little exercise and naturally became very fat, and when the

time for the autumn moult arrived, not a feather was shed. The

songs diminished and gradually died away'-; but when a bird was

gradually brought into the light for a week or two, and meal¬

worms were added to its diet, there was a full resumption of

song.


His experiment tends to prove “ that the sequence of

plumage in these birds is not predestined through inheritance

bringing about an unchangeable succession, in the case of the

Tanager, of scarlet-green, scarlet-green, year after year, but



