Order MIOROPODIFOEMES. 
No. 84. 
Family M1CROPODIDM. 
MICROPUS PACIFICUS. 
WHITE-RUMPED SWIFT. 
Micropus pacificus Mathews, Birds of Austr., Vol. VII., pt. m., p. 276, pi. 348, August 26th, 1918. 
Micropus pacificus Cochrane, Ibis, 1914, pp. 586-588, Oct. (photo of nest and eggs in situ , pi. xxv.). 
Cypselus pacificus , id., Emu, Vol. XIX., pt. 3, pp. 176-178, Jan., 1930. 
At the above reference I did not include the description of the nest and eggs 
of this species. 
best. Circular in shape, thickest at the edges ; slightly concave in the centre. Compactly con¬ 
structed of straw, with a straj 7- feather or two knit together, and stiffened with some glutinous 
matter, the product of the bird. Diameter three and a half inches across and firmly and 
horizontally wedged between the two faces of the cleft in the rock. 
Eggs. Clutch two (sometimes three), white (oblong) ovals; the shell is dull, with no gloss [like 
an egg of Hirundapus caudacutus\. 26*5 to 27*5 mm. by 16-17. Collected on the 12th 
of June, 1914. 
Breeding-season . June (Wei-hai-Wei, China). 
Captain Cochrane, who found these birds breeding off the north-eastern 
coast of China, says :— 
“ . . . It was a considerable surprise to find a small colony of Micropus 
pacificus established on an unpretentious rock of the most modest dimensions, 
both in length and height. This particular rock, much broken up, some 50 yards 
long, and at its highest point 39 feet high, is situated 1,400 yards from the 
mainland, and 400 yards from a respectably sized island, which latter is un¬ 
tenanted by Swifts of any description. Of limestone foundation, the rock is 
seamed with deep fissures and long narrow crannies, and it is in these recesses 
that the White-rumped Swift was found breeding in such elevated situations 
that sea and spray, in their most angry moments, are ineffective to disturb the 
tranquillity of the site chosen. 
66 Altogether seven Swifts’ nests were found ; of these two were in vertical 
crannies, the remainder in horizontal fissures, and all a full arm s-length in. 
Only two nests contained eggs (June 6th) and only three Swifts were seen on 
the rock. The first nest found contained two eggs. The female bird was on 
the nest, and the male bird was underneath the nest, clinging to it with both 
feet. So narrow was the cleft, that the birds were constrained to remain in one 
position, turning round being out of the question. The nest itself, wedged 
between the rock faces, was a small, perfectly round plate of straw, three and a 
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