THE ANTARCTIC PETREL. 83 
little known, though examples were brought home from the Antarctic seas by Dr. 
McCormick so long ago as 1842. The following notes on its wide occurrence in the 
southern oceans will therefore be of greater interest, proving as they do, conclusively, 
that the bird is just as much a regular migrant as Priocella or Oceanites. We observed 
it in June and July as far north as 53° 8. lat. in W. long. 82°, and every bird we then 
saw was freshly moulted. 
Having learned the details of this bird in England, it was not surprising that on 
meeting it in the Antarctic pack ice there should have been some doubt as to its 
identification. It required much faith to see in the richly piebald bird that appeared 
to be almost black and white against the icefloes, any semblance to the faded white and 
buff-brown specimen that was captured in the days of Ross. But the Museum 
specimen was not, as we found out later, altogether at fault. In life, also, the colours 
fade, and the rich dark marking of the first one we met was in reality a colour 
that very soon wears off. 
It is most noticeable in the Antarctic birds how little their feathers stand 
the wear and tear of the summer season. The wind and weather, the alternate snow 
and sea spray, the continuous sunlight for several months in the summer, combine to 
give a bird a very different appearance before moulting to that which it will have when 
the moult is over. In the case of the Antarctic Petrel the change is particularly 
marked. It is marked also in the Skuas and in the Penguins. 
The clean-moulted Thalasseca is a handsome bird, with head and back and wings 
deep chocolate brown, and pure white wing and tail coverts ; and after the autumn moult, 
when the young birds have gone north to the open ocean away from ice, one sees them 
in this dark plumage during the winter months between New Zealand and Cape Horn. 
In November they are still dark, but when the nesting season is over and the summer 
sun has done its work, the richness goes entirely and a pale buff colour takes its place. 
Then comes the autumnal moult in January or February, and the birds take on a 
mottled plumage, as one by one the almost black-brown feathers make their way out 
amongst the faded feathers of the head and back. 
We met the bird in November of 1901, when we first sighted ice, in 62° S. lat. 
and 140° E. long. Two or three followed us a long way to the north again, away from 
the ice, but left us five days before we sighted the Macquarie Islands. They were in 
full dark plumage. 
On our next journey southward a dozen or more met us as we again encountered 
ice in January. They had been roosting on a berg, and were in full moult, with 
primaries missing in the wings, and a mottled plumage of buff and black-brown 
feathers intermixed. Throughout the ice pack we had them with us, and on the 10th 
of January we saw them flying in a flock in a south-easterly direction down the coast 
of South Victoria Land. All that night and the following day we had flocks of them 
around us, some flying at great heights, turning and wheeling together at a given 
signal in contrast to the independent and irregular flight of a flock of Snow Petrels. 
