134 REPORT ON THE MIGRATION OF BIRDS. 
route, they may travel at a higher level without whistling, and 
thus escape the notice of the light-keepers. The schedules from 
the Skelligs and Tearaght have always a special interest, these 
rocks being the greatest breeding-places of sea birds on the 
Trish Coast. Mr M‘Carron estimates the number of Stormy 
Petrels on the Tearaght in July at six or seven thousand. The 
changes of plumage in the Razorbill has been the source of much 
comment by Mr M‘Carron. The sudden and almost complete 
disappearance of the so-called “ Black-billed Auk,” and the re- 
appearance of the Razorbill in breeding plumage in a short 
interval, show that when the old birds arrive to breed, the young 
birds of the previous year leave the neighbourhood of the 
Tearaght, and probably go out to sea. 
A young bird, 8 inches long, and still carrying a few whitish 
downy feathers at the back of the neck, sent up by Mr M‘Carron, 
and obtained on August Ist, has the chin and throat black. An 
older bird, killed on January 13th, has the chin and throat 
white. In Yarrell, vol. iv., p. 60, the chin and throat of a bird 
a week old is said to be white ; and Seebohm says the young in 
down have the underparts greyish white. 
In the report for 1884, it is stated that no Gannets perched on 
the Little Skellig after October 20th, and in the present report 
February 28th is given as the date of their reappearance on this 
well-known Irish breeding station. 
The most interesting stations are those on small islands or 
rocks, or light-vessels at a considerable distance from shore ; and 
the regular occurrence of so many land birds of apparently weak 
powers of flight around these lanterns is a matter of surprise to 
those unacquainted with the facts of migration. 
We believe this inquiry has contributed not a little to en- 
lighten the general public as to the movements of birds, some of 
which were partially known to ornithologists, and others sus- 
pected; but the accumulated data of the observers (making all 
reasonable allowances for errors in identification), are sufficient 
to satisfy the most sceptical of the powers of flight and endur- 
ance possessed by many small birds, and the wide range of the 
migratory impulse. 
An effort has been made this year to shorten the Irish report, 
but the number of birds which strike the lights is comparatively 
small, compared with the large numbers arriving on the coasts of 
