MIGRATION 



to forty miles an hour for crows and sixty for ducks. 

 Swifts unquestionably hold the record with one hun- 

 dred and very rarely one hundred and fifty miles an 

 hour, this during their aerial feeding, not on mi- 

 gration. 



During the two annual seasons, few vessels pass 

 through the major lines of migration flight without 

 affording temporary sanctuary to birds in distress. 

 This is only a hint of the terrible dangers and toll 

 of mortality demanded by migration. Year after 

 year the same number of house wrens return to our 

 orchards, sing from our tree-tops and rear their 

 broods in our knot-holes. If fortune is kind, a single 

 pair of wrens may rear twenty young in a season. So 

 in October two and twenty feathered mites take to 

 the air some night and go to the Gulf Coast or be- 

 yond. The following spring one or both parents 

 often return to the same nesting hollow, and as last 

 year, a second pair is singing in the orchard. But no 

 others are within our range. Ninety per cent — 

 twenty out of twenty-two wrens — have perished, 

 their little bodies devoured by hawk or owl, dashed 

 against the glass of lighthouses, or drowned in the 

 spray of the open ocean. Now and then a house wren 

 spends the entire winter in the north, finding suf- 

 ficient shelter and food, and yet his fellows go hun- 

 dreds of miles beyond the latitude of warmth and 

 abundance of insects, obeying some long-lost law 

 of past initiation of this compelling instinct. 



Migration in other fields presents us with in- 

 finitely greater tragedies. Every wren has at least 



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