INTRODUCTION. 87 
This is the voice of the Nightjar or Goatsucker (Caprimulgus 
europeus). The Bird itself will often suddenly appear, rising 
almost from under the spectator’s feet, flying away with a 
curious, jerking, irregular motion, something like the flight of 
certain Moths. It is a very handsome Bird, having its feathers 
marked with many delicate, dark bars. It lives exclusively on 
insects, especially Moths and Beetles, which its wide-gaping 
Fig. 90. 

Jackson’s Wood-hoopoe (Jrrisor jacksont). 
mouth is admirably adapted to catch. It isa type of a well- 
marked group of about eighty species, arranged in at least five 
genera. 
No greater contrast could well exist between two Birds of not 
very dissimilar size than exists between the Nightjar and the 
Hoopoe (Upupa epops). The latter has now become very 
rare in England, because, unlike the Nightjar, it is no sooner 
seen than it is ‘ obtained” by some zealous collector. Itis a 
