316 



On Size in the Avian Order Tahinares. 



Wilson^s Petrel or Motlier-Carey^s Chicken, the medium- 

 sized Cape Pigeon, and the large Albatross collect at one time 

 to partake of the scraps from a ship, and the smaller birds 

 are satisfied with crumbs left by the larger ones. Resorting 

 from vast stretches of sea to nest on islands, as tlie 

 different species must, the smaller ones seek the protection 



Text-fig. 4. 



"'^oiCg CMCOPjojCort'ij. 



The longer line extending the length of the diagram shows the 

 variation in size in the Tubinares, the shorter line rising 

 to one peak, that in the Longipennes or Gavise. 



of necessarily limited holes and crevices ; the larger, not 

 needing protection, nest in the open. If all were approxi- 

 mately the same size^ each would tend to crowd the other. 



The case in the largely northern Longipennes is the 

 reverse. Instead of being especially adapted to one feeding 

 environment, these are decidedly all-round birds, at home 

 everywhere. Some species are no less truly pelagic than 

 the TubinaiTS, others live inland_, where they feed on 

 insects or even follow the plough. Their breeding range is 

 much more extensive, inland or on the coast, wherever 

 suitable opportunity offers. Such being the case, they 

 compete among themselves much less, but meet with more 



