WINTER SINGING OF THE SONG-THRUSH. 215 



When I arrived the singing was still going on, and I was told 

 that it had attracted notice, as elsewhere. It continued in full 

 strength till the 15th. From that day till January 3rd, in rather 

 colder weather, varied by warm days and cold fog, I heard 

 occasional singing only, as one ordinarily does in mid-winter ; 

 on December 20th, 35th, 28th, 31st, which were stormy days, 

 the birds were silent, and left the field vacant for the Mistle- 

 Thrush. Though there were plenty of Song-Thrushes still to 

 be seen, as well as occasionally heard, I think there was a 

 decided diminution in the numbers during the last half of the 

 month. From January 3rd to January 21st, with the tem- 

 perature varying at 9 a.m. from 25° to 42°, I failed to detect the 

 voice of a single bird of this species. 



It may be useful to exhibit the diminution of song between 

 December 15th and January 3rd in the form of a table : — 



Dull and damp. Not many Thrushes singing. 



Fine. Not many songs. 



Feels colder and drier. Very few songs. 



Open and mild. Few songs. 



Very fine. Much singing, including Mistle-Thrush. 



Strong gale from south. Only Mistle-Thrush singing. 



Fine. Several Thrushes singing. 



Fine and frosty. Two Thrushes sang. 



Cold fog. One Thrush sang. 



Very cold dense fog. One Thrush sang at 9.30. 



Warm and drizzly, with wind. Mistle-Thrush only. 



Soft day after rain. One Thrush sang after sunset. 



Wet and rough. Two or three Thrushes sang. 



Heavy gale from west. Not a voice. 



Very fine. No Thrushes sang. 



Dull and drizzly. Heard one Thrush. 



Great gale. No birds singing. 



Cold rain. One or two Thrushes sang. 



Fine and sunny. One Thrush sang. 



On January 3rd a short period of cold and foggy weather set 

 in, with one heavy fall of snow. I heard no Thrush during this 

 cold weather, nor during the very rapid thaw of the 9th and 10th ; 

 nor did two fine days, the 14th and 15th, which brought out the 

 love-note of the Blue-Tit, and all but induced the Chaffinch to 

 begin, stimulate our Thrushes to start their song again, I 

 returned to Oxford on the 18th, a warm, damp day (therm. 42°), 



Dfc 



c, 15, 



Therm 



. 38. 





, 16. 





42, 





, 17. 





42. 





, 18. 





45. 





, 19. 





33. 





, 20, 





46. 





, 21, 





38. 





, 22, 





28. 





, 23. 





25, 





, 24. 





30, 





, 25. 





52. 





, 26, 





42. 





, 27. 





45. 





, 28. 





45. 





, 29, 





30. 





, 30. 





40. 





, 81. 





38, 



Jan, 1. 





35. 



5 



2. 





28. 



