1546 Birds. 



NATURALIST'S CALENDAR FOR DECEMBER. 



Birds. — On the 10th grouse shooting ends. The ptarmigan (Lagopus mutus) has 

 now assumed its pure white winter livery, and all the waders are now in full wiuter 

 plumage. The various species of gulls often visit inland districts at this season of 

 the year, and in company with rooks, follow the plough in search of worms and the 

 grubs of the cockchafer (Melolontha vulgaris). The golden plovers assemble in im- 

 mense flocks on commons, and in open fields, and if the weather proves severe, the 

 fieldfares, redwings, and other species, descend to low marshy districts, where they find 

 a sufficient supply of various insects. 



Insects. — But very few insects are to be found in this month, though some of those 

 which appeared last month may still he taken, if the weather is mild. — Henry Double- 

 day ; Naturalist's Almanack for 1845. 



Nidification of some Australian Birds. — On looking over vol. iii. of 'Audubon's 

 Ornithological Biography ' a few days ago, I was struck with the great difference be- 

 tween the account there given of the nidification of the booby, gannet, and two species 

 of tern, and my own notes on the same subject made in 1844 and 1845 on the north 

 and north-east coasts of New Holland. The birds I allude to are the Sula fusca, 

 Anous stolidus, and Thalassipora fuliginosa. Of the brown booby of North America, 

 Audubon states, " In all the nests which I examined, only one egg was found, and as 

 most of the birds were sitting, and some of the eggs had the chick nearly ready for ex- 

 clusion, it is probable that these birds raise only a single young one, like the common 

 gannet or solan goose," p. 64. Among the numerous nests of the booby on Bramble 

 Cay, Torres, Straits, in every instance I found two eggs, one usually much soiled, 

 and the other quite clean. According to Audubon, in the Tortugas, the nests of the 

 noddy contained three eggs each, p. 516. On Raine's Islet and Bramble Cay I never 

 found more than a single egg or young bird in one nest out of many thousands which 

 I must have seen, and the same had been previously observed by Mr. Gilbert on 

 Houtman's Abrolhos, off the west coast of New Holland, (see * Annals and Mag. of Nat. 

 Hist.' vol. xiv. p. 450). Again, with regard to the sooty tern, Audubon mentions (p. 

 266) that it " always lays three eggs as its full number," and moreover that "there is 

 less difference between their eggs than is commonly seen in those of water birds, both 

 with respect to size and colouring." On the other hand I have invariably found the 

 sooty tern to lay only a single egg, which, besides exhibited such differences in the 

 size and distribution of the markings, that a series of a dozen or more between those 

 covered with large blotches and others with faint markings, with all the intermediate 

 gradations, might easily be picked out. The circumstance thus briefly related, natu- 

 rally led me to speculate on the probable causes of such marked differences in nidifi- 

 cation, and I am inclined to adopt the easiest mode of accounting for them, by at once 

 cutting the Gordian knot, and questioning the specific identity of the Australian and 

 American species, although Mr Gould, our first authority on the subject, has failed to 

 detect any specific distinctions after a careful examination of specimens from both 

 countries. This appears to be a case for the decision of the comparative anatomist, 

 who, in the present state of the question, alone can set the matter at rest. — John 

 MacGillivray ; Old Aberdeen, September 2oth, 1846. 



