246 ANNALS OF SCOTTISH NATURAL HISTORY 



Interesting 1 Birds at Fair Isle. I have just returned from a five 

 weeks' residence on Fair Isle, where in the course of my investiga- 

 tions I witnessed the passage movements of no less than 82 species 

 of migratory birds. Among the birds observed were several species 

 of special interest (some of them being new to Scotland), and these I 

 propose to mention in this preliminary note, reserving full parti- 

 culars for a future contribution on the results of the year's observa- 

 tions. The rarer species that came under my notice during September 

 and the early days of October were Black-throated Chat (Saxicola 

 occidental! s]. Black-headed Bunting (Emberiza melanocephala], Grey- 

 headed Wagtail (Motacilla inridis\ Red-breasted Flycatcher (Musci- 

 capa parva}, Greater Redpoll (Acanthis rostrata), Ortolan Bunting 

 (Emberiza hortitland), Lapland Bunting (Calcarius lapponicus), 

 and Hoopoe (Upnpa epops). WM. EAGLE CLARKE. 



Peculiar Blackbird's Eggs and their Significance. The 



following record relating to several peculiar clutches of Blackbird's 

 eggs seems to prove that, in cases where the eggs of birds of one 

 species are subject to variation, each individual female of that 

 species lays year after year eggs similar in colour and markings. 



Early in April 1903 I found a Blackbird's nest containing three 

 pure blue eggs, but these were taken before the clutch was complete. 



On iQth April 1905, within a few yards of the same spot, I 

 again found a Blackbird's nest, presumably belonging to the same 

 bird, as it contained two pure blue eggs and a third of ordinary 

 Blackbird's-egg type. This nest was also robbed before the clutch 

 was complete, but by 26th April a new nest had been constructed 

 close by the old one, and two eggs had been laid, both pure blue 

 in colour. On 3oth April, when I again looked at the nest, the 

 bird was sitting closely on a clutch of three eggs, one of which, 

 the last laid, was of ordinary markings. Again the nest was robbed, 

 and again, on loth May, I found the bird sitting on another nest, 

 which contained a clutch of eggs similar to that found on 3oth April. 



The next nestful of these peculiar eggs which I found was dis- 

 covered on 8th April 1906, and consisted of two unspotted eggs: 

 on gth April the number remained the same, but a pure blue egg 

 was found on the ground a few yards away ; this egg I placed in 

 the nest, which, however, proved to be deserted. 



This year I did not find the unspotted Blackbird's eggs until 

 28th June, when I found a deserted clutch in a nest built about 

 50 yards from the former sites. This clutch consisted of five 

 eggs : four blue and unspotted, and the fifth of ordinary markings. 



It is, of course, impossible to prove from the above scanty 

 observations that all these nests belonged to the same pair of birds ; 

 yet, as, with the exception of the 1907 nest, all were built within 

 a space of about 100 square yards, it is quite probable that 

 they did. 



