84 " COASTING " 



the bird reaches the tree, the impetus carrying 

 it up to the spot. On gaining the tree the 

 woodpecker remains for a moment immovable 

 and rigid, when it has the appearance of a 

 natural excrescence projecting from the tree. 

 I have used the word " coasting " as applied 

 to a certain description of flight. By " coast- 

 ing " I mean straightforward flight on motion- 

 less wings after momentum has been acquired. 

 For example, partridges fly and " coast " 

 alternately ; a very graceful flight shared only 

 by birds of the same order. Partridges, with- 

 out moving their wings, sometimes " coast " 

 for long distances ; flying in this fashion they 

 will rise at and clear a hedge, to sink again on 

 the opposite side. To effect this undulatory 

 movement the bird has only to incline one 

 degree above the mean level on approaching 

 the hedge, and after clearing it, reverse the 

 order. Proceeding in this way the covey skims 

 over the field and alights on the further side ; 

 but the mode of pitching is very different to 

 that of perching birds. In the case of part- 

 ridges, birds of some weight, the momentum 

 up to the last moment is considerable, and 

 must be summarily checked to allow of an 

 easy descent. There is no discussion amongst 

 these partridges as to where they shall settle ; 

 for as already suggested, the birds are linked 



