PETROCHELIDON SWAINSONI
ERYTHROGASTRA.
IIirundo erythi'ogaslcrxsivainaoni, Salvin, Ibis, 1888, p. 256.
T h e figure of tlic hybrid Swallow is taken from the Cozumel specimen in the Salviu-
Godman collection. Mr. Salvin bas given the following account of it
“ A single specimen, shot in May 1885 by Mr. Gaumer on Cozumel Island, wo have
little doubt is a hybrid between Hinmdo erytlirogaster and Petrochelidon sicainsom, as it
curiously combines tho characters of both birds. The forehead is the same in hotii
species, but tbo ear-covcrts and the collar arc steel-blue, as in H. erythrogaster; tho tail
is also furcate, though to a less extent, and the lateral feathers have the characteristic
white spots ; the wings, too, are as loug as those of II. erythrogaster, and the under
tail-covcrts are tinged witli rufous. Tho characters it has with P. smainsoni are the
colouring of the under surface, including the black gular patch ; it also has the rump
rufous grey. Instances of hybrids between II. erythrogaster and P. pyrrhonota have been
recorded, but this is tbo first we have met with in which P. swainsoni appears to have
been one of the parents.”
It will be seen that the colour of the plumage partakes of the cliaracteristics of botli
species, tbe general features of tbo Petrochelidon being preserved, while tbe slightly forked
tail, and, above all, the white spots ou the latter, arc tbe characters of a true IIirundo.
We have considered that tbe strain of tbe Petrochelidon is stronger in this curious hybrid
than that of tbe Ilirundo, and have named it accordingly.
That the American Swallow {IIirundo erythrogastra) does occasionally cross with
the Cliff-Swallow {Petrochelidon pyrrhonota) is also known, and a full description of a
hybrid between these two species is given by Mr. Spencer Trotter iu tbo ‘ Bulletin of
the Nuttall Ornithological Club ’ for 1878. This specimen was procured at Liuwood,
Delaware County, in Pennsylvania, ou tbe 22nd of Alay, 1878, by Air. C. D. M ood.