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CORDEAUX: HELIGOLAND. 



Mr. Gatke, when describing to me, in his garden one afternoon, 

 the migration of the Goldcrest, said, it might be on some still bright 

 afternoon in October, suddenly from above a small bird drops into the 

 shrubs, then another, then two or three, after which numbers keep 

 droi)ping in, not only here, but into the neighbouring gardens. Some 

 of these fragile-looking little wanderers commence feeding, or making 

 a pretence to feed, others sleep, like dots of feathers amongst the 

 shrubs. The sun has set and twilight deepens, a single planet shines 

 like a distant lamp in space. Something tells them that it is time to 

 move : half-an-hour after sunset one is seen to rise, flying directly 

 upwards, wings and body being kept perpendicular to the plane of 

 the horizon, like a small spread-eagle. A tiny note sounds out aloft, 

 then one and then another rise ; the notes are repeated, now from 

 one, now from another, till the whole flock is called together and on 

 the wing. Then, circling once or twice, they strike off into the 

 gathering darkness towards the western isles. 



In considering the phenomena of migration, due allowance must 

 be made for the finer senses of the lower animals, , their better 

 remembrance of locality and stronger vision. It is easy to under- 

 stand how birds with their acute sight, and migrating in the day time, 

 may discern Heligoland from the nearest coast to the east, only forty 

 miles away, and from Heligoland be able to see Borkum and then 

 Ter SchelUng, and the southward trend of the European coast-Hne. 

 Yet in the night, when birds most migrate, these landmarks would be 

 invisible, and in the great sea passage of 360 miles between Heligo- 

 land and PLngland there are no landmarks to give even the general 

 direction. There is the light of star or planet, and that these are 

 an important factor in migration there can be no doubt, but to what 

 extent stars and planets act as actual guiding points we shall never 

 be able to tell, although we know that when the sky is obscured with 

 heavy clouds or by fog, birds not unfrequently lose their way, and 

 when the stars again become visible, or the m.oon rises, speedily 

 appear to find the right course again. 



It is known that in foggy thick w^eather migrating birds become 

 much puzzled, and it is invariably under these adverse meteorological 

 conditions that they are observed about light-houses or light-vessels, 

 or clamorously careering above the lights of a town. The rays from 

 a light-house or light-ship are not thrown upwards, but are directed 

 to the horizon ; consequently, on a foggy night, to birds passing some 

 distance overhead the hght from a light-vessel would appear as an 

 illuminated circle, a spot where the fog seems less' dense, or a little 

 brighter than the surrounding gloom, more or less distinct according 

 to the level of flight ; a flock of migrating birds seeing this light 



Naturalist, 



