242 THE BIRDS OF HELIGOLAND 



The home of this Thrush is in the northern parts of eastern 

 Asia. Seebohm found the nest within the Arctic Circle, on a 

 tributary of the Jenesei, and Dybowsky met with breeding birds in 

 Daiiria. As the bird has been received even from Japan, it is 

 probable that its nesting places extend into the extreme eastern 

 parts of Asia. 



69. Olive-backed Thrush [SWAINSON'S DKOSSEL]. 

 TURDUS SWAINSONI, Cabanis. 



Turdus Swainsoni. Naumann, xiii. 275, pi. 355, fig. 4. 



Wilson's Thrush. Richardson and Swainson, Faun. Bor. Amer., p. 182. 



Turdus Swainsoni. Seebohm, Cat. of Birds of Brit. Mus., v. 201. 



The first example of this small American Thrush observed in 

 Europe was caught, according to Giglioli (Avifauna Italica,^. 100), 

 at Genoa in the autumn of 1843. The bird is later reported to 

 have occurred in Belgium, but according to Naumann, ' this report 

 has not been verified.' On the 2nd of October 1869, however, a 

 bird of this species was met with in Heligoland. It was pre- 

 pared as a specimen by myself and is in my collection. It had 

 been so much frightened by a Sparrow-hawk that it fled up the 

 steps of the wooden stair leading up to the cliff i.e. the Highland, 

 or Oberland among the people passing there at the time, and 

 allowed itself to be caught by the hand of a young gunner, Jacob 

 Aeuckens, without making the least effort to escape. 



According to Giglioli's further notes, another example of this 

 Thrush was caught in Upper Italy in 1878, and exhibited in the 

 museum of Roveredo; and, finally, there is in the museum at 

 Hamburg an example caught several years ago in Holstein. 

 This example, which I was enabled to compare with my own 

 specimen, resembles the latter completely, and is undoubtedly T. 

 swainsoni. 



All the examples noted above as having been met with in 

 Europe were captured during the autumn migration, which, 

 judging from analogous phenomena, would lead one to presume 

 that they originate from eastern Asia. This assumption is further 

 supported by the fact that during Nordenskj old's Arctic Expedition 

 three small Thrushes were caught on the Tchukchee Peninsula, on 

 the 1st, 8th, and 10th of June. These are described as var. alicice 

 (Baird), a pale eastern aberration of T. swainsoni (Palmen, Bear- 

 beitung des Ornithologischen Materials. 1 As however the original 

 home of both forms is in North America, whence T. alicice has 

 advanced into Asia, we may therefore assume that T. swainsoni, 



1 Report on the Ornithological Materials collected by the Expedition. 



