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Prof. W. E. D. Scott,



My experiments in the season of 1902 included, besides

the above, an additional brood of Song Sparrows, which con¬

tained four Song Sparrow’s and one Cowbird’s egg. All of these

hatched and lived for periods varying from four to seven days,

none of the birds leaving the nest; I also experimented with a

clutch of five fresh eggs of the Yellow-winged Sparrow

(Ammodramus savannarum passerinus ), which I divided between

two different parent Canaries, leaving two Canary’s eggs with

three Yellow-winged Sparrow’s eggs, and in the other case two

Yellow-winged Sparrow’s eggs with three Canary bird’s eggs.

Both clutches were hatched, there being five young birds in

each nest. The Canary birds in both cases were reared and

reached maturity, but the young Yellow-winged Sparrows which

were also hatched died at ages varying from four to seven days.


I also attempted during this season to raise young

Bobolinks under Canaries {Dolichonyxoryzivorus) ; to this end on

May 28th, having found a nest of five eggs, I introduced two of

them to a large breed of English Canary, leaving two of her own

eggs in the nest ; the other three Bobolink’s eggs I placed under

another Canary of a similar kind, leaving two Canary eggs in

addition. This Canary threw out her own eggs, but retained the

Bobolink’s eggs, and incubated them till they were hatched,

which was on June 8th. The three young Bobolinks lived for

three days, when one of them died ; the remaining ones died on

the fifth day. The other Bobolink’s eggs, under the English

Canary, were also hatched on the eighth, but both died on the

tenth of the month ; the young Canary birds hatched at the

same time were reared to maturity, when I no longer followed

their history.


In the spring of 1903 I tried several similar experiments,

sometimes putting but one egg of a wild bird with a clutch of

Canary’s eggs, and never giving one Canary an entire comple¬

ment of wild bird’s eggs. In all cases the eggs were hatched

and in no case did the foster-young attain an age of more than a

week, though it is to be remembered that in every case young

Canaries in the same brood with the foster-birds flourished and

reached maturity. During the season of 1903 I took two young

Song Sparrows, just beginning to show the feathers, and put



