THE LOVE DISPLAYS OF BIRDS 229 



often accompanied by the display of some special 

 ornate development, and the terrestrial move- 

 ments of others, likewise attended with the 

 parade of certain decorations. Of the aerial 

 performances we may here select a couple from 

 the Humming-Birds. Stolzmann tells us how 

 he watched entranced the aerial ballet of that 

 marvellous racket-tailed Humming-Bird, the 

 Loddigesia mirabilis. It is one of the rarest 

 species, and down to 1880 (when Stolzmann 

 practically rediscovered it) but a single skin 

 was known in any scientific collection. He 

 found that these Humming-Birds were in the 

 habit of assembling at certain spots on the bare 

 plateau to indulge in aerial movements. Two 

 birds would first of all hover in the air opposite 

 to one another with their bodies in a vertical 

 position, then with expanded tail they flew first 

 to one side then the other uttering a clicking 

 note. Sometimes several males took part in 

 this performance. At other times one bird 

 would hang below a slender branch as another 

 bird went through the mazy dance, when sud- 

 denly the position of the two performers would 

 be exactly reversed, one taking the position and 

 performing the actions of the other. Meantime 

 the wonderful racket-shaped tail is moved in a 



