367 



SOME OBSERVATIONS ON THE S0NG-PERI013S 

 OF BIRDS. 



BY 



C. J. AND H. G. ALEXANDER. 



The observations on which this article is based have been 

 made during the last three years, chiefly in the Tunbridge 

 Wells district (Kent and Sussex) and at Wye (Kent), but 

 also at Reigate (Surrey) and Rye (Sussex). They do not 

 profess to represent the conditions prevailing anywhere 

 except in the eastern j^art of the Weald. 



No doubt the observations we have made will present no 

 new facts to those who have paid attention to the subject, 

 but we think it may be well to have them collected 

 together here for comparison with those made in other 

 districts. 



In the middle of the song-period all the individuals of a 

 species found in any locality sing every day, but at the 

 extremes of their song-periods birds are much affected by 

 situation and weather. The majority of birds sing most 

 in hilly, partially wooded districts, but Skylarks sing 

 equally wherever they are found, except that where they 

 are numerous there is more chance of one singing' under 

 unfavourable conditions. Weather probably acts chiefly 

 through the food supjDly. For instance. Thrushes stop 

 singing directly there is a frost which lasts through the 

 day, and after a long frost they do not resume their song 

 fully for some days ; Hedge-Sparrows and Robins do not 

 stop unless the frost is considerable, and where they can 

 get plenty of crumbs they will sing every day during severe 

 weather, such as that in January of this year. But 

 weather also acts directly : in the very mild period towards 

 the end of December, 1907, Mistle-Thrushes sang a good 

 deal. Creepers occasionally, and even a Blackbird was 

 heard sinaina" on two evenino-s. There is no reason to 



