7 APRIL 1877, Page 3

An amusing letter from Heligoland to last Saturday's Times, signed,

" H. Gatke," states that on that little rock at all events, and as the writer believes elsewhere in climates-colder than England, the sparrow is a partially migratory bird ; and Mr. Gatke main- tains that in some cases,—the case of the blackbird, and also, he thinks, of the sparrow,—the elders with well-seasoned constitu- tions stay through the winter, while the younger ones go in search of a warmer climate. In Heligoland, though the sparrows would multiply rapidly but for a steady flow of emigrants after each brood has reached maturity, the sparrow population remains nearly stationary. No doubt they find the place too small for an in- creasing population, wherefore the young sparrows are forced to find a career on the Continent,—or, perhaps—if they show the same marked preference for British institutions evinced by the sparrows imported into the United States, which immediately left for Canada,—in England. Is it certain, however,—at all events in cases in which the older birds do not migrate during the winter,—that the migration of the young is due chiefly to climatic causes at all, and not rather, in the main, to the love of travel ? The fact that they travel in troops only shows that they adopt the ordinary precaution of the timid in dangerous countries,—to get up caravans. Indeed, do we not follow their example still in our Cook's tours ?