ANIMAL FLIGHT 1 27 



Many syrphid and bombyliid flies, some horse-flies or taban- 

 ids, the hawk-moths and the humming-birds, all of which 

 hover in the same way, are able to fly backwards slowly, re- 

 versing the action of their wings. You can see a humming- 

 bird do this as he goes from flower to flower. 



Very few insects have a definitely developed tail capable of 

 being used for steering, some of the hawk-moths have move- 

 able tufts of long hairs on the end of the body which may be 

 used for this purpose, and one of the small parasitic wasps 

 has a very remarkable tafl of two thin plates crossing each 

 other at right angles in the middle. IMany butterflies, like the 

 swallow-tails, and a number of moths, like our common luna 

 and its various Asiatic relatives, have the hind wings produced 

 into so-called tails, which may be very long; in some species 

 only the males have them. In other insects, as in certain ant- 

 lions, the fore wings may be normal, but the hind wings are 

 very narrow and extremely long, and more or less twisted. 



In all flying animals the steering is done chiefly or entirely 

 with the wings. Many bats are taifless, but they fly quite as 

 well as the bats with tails. The long-tailed birds, like the 

 cuckoos, forked-tailed, scissor-tailed and paradise flycatchers, 

 long-tailed trogons, tailor-birds, emu-wrens, lyre-birds, turkeys, 

 curassows, pheasants, etc., are relatively weak fliers, while all 

 the birds remarkable for very long flights, like the plovers, 

 curlews, godwits, ducks, geese and swans, or for long con- 

 tinued gliding flight, like albatrosses and shearwaters, are 

 short-tailed. Soaring birds to increase the lifting surface oiostly 

 have large broad tails, just as they have very broad wings. 

 Most long- tailed birds are small; if large they are ground 

 living; if good fliers the elongated feathers of the tail are 

 reduced to two which are usually very narrow, the two outer- 

 most in the swaUows, terns, some flycatchers, some humming- 

 birds, etc., the two central in the macaws, lories, tropic-birds, 

 other flycatchers, other humming-birds, etc. Birds which 

 pounce upon their prey or feed after the manner of bats, such 

 as most hawKs, falcons, kites and owls, goatsuckers, night- 



