VOL. VII.] NOTES. 828 



III another oyrie, visited un May 17tji, 11313, wlieii the 

 three chicks were a few days old, one was quite twice the 

 size of the smallest, while the third was intermediate in 

 size. On June 14th much the same difference in size and 

 development could be seen, and on June 25th, while two 

 of the young Falcons had left the e3n:ie, one was still there. 



The difference in size and development would be accounted 

 for by a difference in the date of hatching, which itself would 

 be accounted for by the bird starting to sit on the first egg. 



Douglas A. Scott. 



[Mr. Scott's note is valuable as throwing some light on 

 a subject on which at present we have no rehable data, 

 viz., the incubation-period of the Peregrine. If the first- 

 mentioned nest contained two fresh eggs on April 29th, 

 the first egg must have been laid on A^^ril 26th or 27th. 

 Unfortunately we cannot say whether the egg which dis- 

 appeared was the earliest laid or one of the later eggs, 

 but as one young bird hatched by June 1st it is possible 

 that this was the second egg laid, in which case the first might 

 have been hatched as early as May 29th. The maximum 

 incubation-period in this case would be thirty-two days, 

 but if the egg hatched on May 31st was the first laid, the 

 period might possibly extend to thirty-five days. Mac- 

 gillivray estimates it at a month on the authority of Mr. 

 G. Craven, but this is obviously only approximate, and 

 Tiedemann's statement (18-19 days) is certainly erroneous. 



That the eggs of the Peregrine are laid with an interval 

 of a clear day between each, and that incubation begins 

 before the clutch is complete, may be regarded as certain, 

 though curiously enough Dr. F. Heatherley, who has written 

 recently on the subject of the Peregrine, was apparently 

 unaware of the first rule, which probably holds good with 

 all the Raptores. — F. C. R. Jourdain.] 



MARSH-HARRIER IN SUSSEX. 



On March 9th, 1914, a male example of the Marsh-Harrier 

 {Circus ceruginosus) was shot at Wartling, Sussex, and I 

 examined it the same day. When shot it had just killed 

 a Partridge. H. W. Ford-Lindsay. 



GADWALL AND LITTLE GULL IN ESSEX. 



It may be of interest to record that a fine old drake G-adwall 

 {Anas strepera) and an example of the Little Gull {Larus 

 minutus) were obtained at Manningtree, Essex, in December, 

 1913. The latter is now in my possession. 



J. Beddall Smith. 



