104 BRITISH BIRDS. 



and last, as in 1908 and 1909. In the district most 

 thoroughly worked, the following are the nunabers of 

 Chiffchaffs :— 1908, 21 pairs ; 1909, 24 pairs ; 1910, 21 

 pairs ; 1911, 11 pairs. Compare this with the following 

 figures in the same district (only 1910 strictly com- 

 parable to 1911 owing to my absence from home from 

 about April 20th to June 20th in those years) : — White- 

 throat [1908, 58 pairs ; 1909, 58 pairs ;] 1910, 25 pairs ; 

 1911, 34 pairs : — Lesser Whitethroat [1908, 16 pairs ; 



1909, 14 pairs ;] 1910, 5 pairs ; 1911, 7 pairs : — Blackcap 

 [1908, 12 pairs; 1909, 12 pairs;] 1910, 7 pairs; 1911, 

 9 pairs :— Garden- War bier [1908, 10 pairs ; 1909, 17 

 pairs;] 1910, 2 pairs; 1911, 4 pairs: — Willow- Wren 

 [1908, 77 pairs; 1909, 85 pairs;] 1910, 57 pairs; 1911, 

 44 pairs :— Tree-Pipit [1908, 38 pairs ; 1909, 34 pairs ;] 



1910, 13 pairs; 1911, 21 pairs :— Red-backed Shrike 

 [1908, 4 pairs; 1909, 4 pairs;] 1910, 3 pairs; 1911, 

 4 pair? The numbers in 1908 and 1909 are in almost 

 all cases very similar, and these are the most reliable 

 figures. Possibty the snow in April had some effect on 

 the number of Willow- Wrens observed in 1911, and 

 I have reason to think it also had on the number of 

 Wheatears that reached their nesting-places in some 

 districts. Such Chiff chaffs as did come were later than 

 usual in proportion to the migrants next to arrive. The 

 only Chiffchaff that had arrived before the snow did not 

 survive it, and I have not included it in the number 

 for 1911. 



There is a further point that I should like to mention. 

 By now I have notes of quite a number of cases w^here 

 birds have reappeared at a place after an absence of a year 

 or two. In some cases it may be that one of the pair 

 only came, and could hot find a new mate one year 

 but found one again the year after. But I feel little 

 doubt that in the majority of cases the place is filled 

 by a fresh pair, even though they may inhabit just the 

 same area and sing from just the same points. One 

 can often say with great certainty, for example, that 



