Oct. 19, 1 888.] 



SCIENTIFIC NEWS. 



419 



"On the night between October 28th and 29th, 1882," 

 Mr. Gatke remarks, " we have had a perfect storm of 

 goldcrests, poor little souls, perching on the ledges of the 

 window-panes of the lighthouse, preening their feathers 

 in the glare of the lamps. On the 29th, all the island 

 swarmed with them, filling the gardens and over all the 

 cliffs — hundreds of thousands ; by 9 a.m. most of them 

 had passed on again " (" Migratory Report," 1882, p. 49). 

 Birds when migrating dislike a favouring as much as an 

 absolutely contrary wind, preferring a wind from the 

 side. They appear to fly at a high elevation, and when 

 they arrive at Heligoland to drop down as it were from 

 the clouds. Mr. Seebohm supposes that they migrate by 

 sight and not by instinct, but the gravest difficulties 

 appear to me to beset the former theory. In the spring 

 migration (of course I take for granted a knowledge of 

 our spring and autumnal migrations) the adult males 

 usually come first, then the adult females, next the birds 

 of the year, then wounded or crippled birds. On their 

 return various stragglers first come, then the young 

 birds, and finally the old birds. " The conclusion I came 

 to," says Mr. Seebohm, " was that desire to migrate was 

 an hereditary impulse to which the descendants of 

 migratory birds were subject in spring and autumn, and 

 which has during the lapse of ages acquired a force 

 almost, if not quite, as irresistible as the instinct to breed 

 in spring." Here again allowance must be made for the 

 prepossessions in the writer's mind. " Among true 

 migratory birds," he continues, " it appears to be a 

 general rule that the farther north a species goes to breed 

 the farther south it goes to winter." 



During the land migration, the same author thinks 

 that birds travel slowly during unfavourable weather, 

 and rest at night, but for a sea journey they wait for a 

 favourable wind and then come over en masse. Mr. 

 Cordeaux, a member of the Migration Committee, 

 agrees with this. " In the Cheviots," he says, " I have 

 observed for two years in succession that the streams of 

 small migrants from Scotland follow those main valleys 

 which run nearest north and south, sticking closely to 

 the lowest levels, where the brushwood and bracken 

 beds offer greater privacy and security than the bare 

 fell sides. Birds also, when migrating, follow from 

 choice low-lying tracks of land and river-courses in 

 preference to elevated plateaus and the summit-line of 

 mountain ranges" ("Migration Report," 1886, p. 52). 

 When birds cross the German Ocean, if fine they fly at 

 a great height ; if wet and cloudy they keep but a 

 little distance above the waves. There is doubtless 

 much mortality in bad weather, even among the larger 

 birds, during their migration. The Lincolnshire coast 

 during a gale has been found strewn with the dead 

 bodies of the hooded crow. When countries are over- 

 crowded with birds some appear to migrate for good and 

 all into distant lands. The curious irruptions of 

 the sand grouse into England in 1863, and again in the 

 present summer, appear to be migrations of this nature. 

 Migration, then, among British birds may be con- 

 sidered as of three kinds. First, the regular stream of 

 birds which come here in spring to breed and which 

 leave us again in autumn, and again that similar 

 stream which appears in October and leaves in February 

 or March ; next, the continuous migration of our com- 

 mon birds, blackbirds, jays, etc. ; and thirdly, exceptional 

 immigrations, such as that of the sand grouse just 

 named. 



As for the continuous migration of common birds, it 



may be noticed that this movement has only been dis- 

 covered of late years, and that the reports from the 

 different lighthouses show constant examples of it. 

 Thus a migration of the same kind of birds frequently 

 occurs, but in opposite directions, across the North Sea. 

 Crows, rooks, jackdaws, starlings, larks, sparrows, bunt- 

 ings, and finches, have been noticed there crossing each 

 other. Indeed, Professor Newton says, " Hence we are 

 led to the conclusion that every bird 01 the northern 

 hemisphere is to a greater or less degree migratory in 

 some part or other of its range." Mr. Cordeaux takes 

 blackbirds as an example of this tendency, and says : 

 " In the autumn, during September, tho young of the 

 year leave their summer quarters, and their place is 

 shortly taken by others, likewise young birds, coming 

 in October and November from districts which lie 

 directly east or south-east of Great Britain. Should an 

 English winter prove severe, or even partially so, our 

 old birds will also leave, and in their place we have an 

 influx of old blackbirds from the Continent, pushed 

 forward from similar causes. In the spring the Con- 

 tinental visitors disappear, and our so-called resident 

 blackbirds come back to their nesting quarters. As far 

 as our knowledge extends the normal conditions of 

 locality and climate over the whole area are such as do 

 not necessitate a regular interchange of the members of 

 their respective avi-faunas. There is apparently no 

 reason why our rooks, starlings, skylarks, and blackbirds 

 should not be able to winter in England just as well as 

 abroad ; " and he adds : " Such are the ordinary pheno- 

 mena of migration; a movement which is as regular and 

 persistent as the flow and ebb of the tide." And once 

 more : " Practically such birds as the lark and the star- 

 ling are migrating all the year round." The robin, too, 

 seems almost always moving from woods to the vicinity 

 of houses and back again, and even to far distant 

 countries such as Africa. 



With regard to the third kind of bird migration — that 

 which is local, occasional, and exceptional — it must be 

 remembered that it is only so because we do not as yet 

 see the full purpose which thus stirs so many birds at 

 once. Doubtless, want of food is one great cause, or 

 abundance of food in an unusual locality. Thus in 

 1885 the abundance of Arctic ice brought down mollusca, 

 entomostraca, etc., to more temperate seas, and so vast 

 quantities of gulls were observed in the Firth of Forth 

 feeding on them. Again, the sand grouse (Syrrhaptes 

 paradoxus), which visited our shores this summer, 

 "from the short time necessary for incubation," says 

 Mr. Tegetmeier, " and the rapid growth of the young, 

 increases so rapidly that it may have been compelled to 

 seek new pastures and to extend its range. It could 

 not traverse northward for climatic reasons ; eastwards 

 its range is limited by the Pacific, southward is the 

 larger bird of the same genus (S. Thibetanus), and it 

 therefore proceeded westward." Cold is another cause 

 of abnormal migration. Birds are pushed on as it 

 were by it from a bleaker into a more sheltered district. 

 A large ["and unusual influx of ring-ousels appeared 

 at Spurn Point, Yorkshire, in May this year, and at the 

 time of writing an abnormal migration of crossbills {Loxia 

 uirvirostra) is taking place from Germany. Some 

 have appeared on the coast of Holderness, in York- 

 shire, and one was captured and kept on board the 

 light-ship at the Spurn for a week before it escaped. 

 In a letter to Mr. Cordeaux, dated July 1st, 1888, 

 Mr. Gatke sends the following interesting notes of 



