T i lA L A S S ID J S O M A W H U S 'O f f l : Bmutjp,
THALASSIDROMA WILSONII, Bonap.
Wilson’s Storm Petrel.
Procellaria Wiisonii, Bonap. in Joum. of Nat. Sci. o f Philad., vol. iii. p. 231. pi. ix.—Ord’s Reprint o f Wils. Am.
Om., p. 94.—Steph. Co'nt. of Shaw’s Gen. Zool., vol. xiii. p . 224.—Zool. Jo um . vol. i. p. 425.
Thalassidroma Wiisonii, Bonap. Synopsis o f th e B irds of the United States, p. 367.—J a rd . Edit, o f Wilson’s Am.
Om., vol. ii. p. 381. pi. lx. fig. 6.—Audubon, Birds o f Am., pi. celxx. fig. 1.—lb . Om. Bio., vol. iii.
p. 486.
Procellaria pelagica, Wils. Am. Ora., vol. vii. p . 90. pi. lx. fig. 6.
Wilson’s Stormy Petrel, Nuttall, Manual, vol. ii. p. 322.
Oceanites Wiisonii, Keys, et Bl.—G. R. Gray, L is t of Gen. o f B irds, 2nd Edit. p. 99.
Thalassidroma Oceanica, Kuhl, Monog., tab. 10. fig. 1.— L ist of Birds in Brit. Mus. Coll., P a rt iii. p. 161.
I po s se s s a specimen of this bird which was sent me by his Excellency Governor Grey, who killed it in the
South Atlantic. It is also one of the most abundant species of the genus inhabiting the Australian seas: I
observed it in great numbers within sight o f the shores o f Van Diemen’s Land, and shot and preserved
several specimens during my passage from Sydney to Hobart Town in April 1839; I also encountered it in
the following year in the seas between Sydney and New Zealand, while on my passage towards Cape Horn.
On carefully comparing these with others from the North Atlantic no specific difference was observable,
but the former were a trifle larger than the latter.
On my voyage to Australia I encountered the Thalassidroma Wiisonii within a day’s sail o f the Land’s End,
and continued to observe it from the deck o f the vessel from thence across the Bay of Biscay to Madeira,
its numbers gradually lessening as we approached the tropics, within which it was never seen. May we not
therefore infer that in the same zone of both hemispheres this species finds a natural asylum, if the slight
difference in size I have mentioned be not o f sufficient importance to warrant their being considered as
distinct ? Certainly’I am not aware of any other species o f Petrel being found on both sides of the equator.
It is exceedingly active when flying, its wings being kept fully expanded ; it also makes considerable use
of its feet, patting and leaping over the surface of the water, with its wings extended upwards and its head
inclined downwards, to gather any food that may present itself. Its usual diet consists of mollusca, small
fish, Crustacea, and any kind of greasy substance that may be floating on the water.
The sexes are so precisely similar that they can only be distinguished by dissection.
The head, neck, back, wings and breast sooty black, the wing-coverts passing into pdle brown at the extremity
; primaries and tail black; upper and lateral portions of the under tail-coyerts white; ¡rides dark
hrown; bill and feet black ; webs yellow for three parts o f theirlength from the base.
The figures are somewhat smaller than the natural size.