Incuba- 
tion, &c. 
466 NATATORES. STERNA. TERN. 
before it is discoverable by the eye. If much disturbed by 
being fired at, or if the eggs be repeatedly taken at the com- 
mencement of the season, it deserts the station first selected, 
and retires to some other place, less liable to molestation. 
Such a migration took place about three years ago in the 
colony which had long frequented a particular islet of the 
Fern group, for, in consequence of some misunderstanding 
between the proprietor and the person who had the care of 
these islands, the fishermen on the coast, and boats from pass- 
ing vessels, made, for one or two seasons, unrestrained irrup- 
tions upon the feathered inhabitants ; and although many of 
the other species adhered to their usual haunts, the Sandwich 
Terns entirely deserted theirs, and fled to Coquet Island, 
where, from being better protected, they reared their young 
without farther molestation. Within the last two years, un- 
der another tenant of the islands, a considerable body of 
these birds has returned, but to a site upwards of a mile distant 
from the one formerly occupied. As soon as the young birds 
become tolerably fledged, but before they are altogether able 
to fly, they frequently take to the water, swimming off to 
the smaller rocks, where they continue to be fed by the pa- 
rents until capable of joining them in their fishing excursions. 
With the exception of the Caspian and Gull-billed Terns, 
which can only be considered as occasional stragglers to our 
coasts, all the other British species are regular summer visi- 
tants. The time of their arrival is about the middle of 
May ; incubation commences in the first week in June, and 
nearly the whole have again taken their departure for more 
southern latitudes by the end of September.—The eggs 
of this bird are three or four in number, for the reception of 
which a shallow hole is scratched amongst the sea-campion 
(Silene maritima), or other plants that may happen to grow 
on the selected place. In size they are about equal to those 
of the Golden Plover, and are usually of a cream or wood- 
brown colour, blotched with dark brown and black, and with 
other spots of a lighter shade appearing as it were beneath 
