THE OSPREY 



85 



BIRDS VS. DRAGONFLIES. 



JAMES G. NEEDHAM, CORNELL UNIVERSITY. 



ture out over open water, fly very close to the 



ice (an inch or less above it,) and so are not 



ily picked up. Only birds that can skim the very 



\ce of the water or that can venture to hunt them 



ig the reeds are likely to be found feeding upon 



these. My esteemed correspondent, M. 



Rene Martin, has published (in Bull. Soc. 



E\V observations on the inter- Ent. de France for 1891 ) the most careful observation 



action of birds and dragonflies on this subject yet recorded, and from his account I 



have been recorded. It is not translate the following : 



that they are either uninterest- "'The Hobby' (Faiio sii/i/iiiU-o) courses like an 



ing or valueless, but that the arrow the borders of ponds at a distance of five or 



qualifications and conditions six paces from the bank. One may watch it for an 



requisite for making them sel- hour while it unceasingly follows the selfsame course, 



dom meet. The ornithologist Then it suddenly descends to start again after a sec- 



is generally a 'bird man' and ond and recommence its maneuvers. It is difficult 



nothing more, and the entomol- at first to see what the little hunter is doing ; its 



ogist is generally a 'bug man' flight is so swift one gets but glimpses of it. But upon 



and nothing more : the collector of insects rarely car- shooting it, its stomach is found filled almost entirely 



ries a gun and the collector of birds rarely knows one with large dragonflies. It has only torn off the wings 



insect from another. To mend the ills of our inevit- of its victims and then has swallowed them whole, 



able specialization it were better for us who work in "Nests of the 'Hobby' are commonly observed in 



the fields wide apart to come together once in awhile June : the ground beneath them is covered with 



to compare notes. dragonfly wings mixed with other debris. It is 



It will readily be imagined that whatever contact therefore certain that this Hawk, at least when it 



between birds and dragonflies occurs is to the advan- nests near ponds, feeds its young upon dragonflies 



tage of the birds. We know some fossil dragonflies and thus consumes a great number, 



that might have made things livelier — great 'darners' "While the large dragonflies of the marshes are 



more than a foot long, with wings expanding eighteen exclusively pursued by the Hobby, the damselflies, 



inches — but those of recent times, while generally disdained by the hawk, are eaten by the Swift 



able to keep out of the reach of bird enemies, are (^Hydroclu-lidoii fissipes) and the destruction of these 



not the aggressors. The birds, of course, capture little species takes place on a large scale since every 



them solely for food, the one interesting exception pond has its hundreds of swifts, and out of twenty 



known to me being that of the Egyptian bee-eater (/J/c'- stomachs of these birds nineteen will in general be 



;7'/.\/f;j-/(7/.f), which lines its nest with dragonfly wings, found crammed with Agrioiis. The Swift swallows 



Certain habits of these insects determine the nature the insects whole without tearing off their wings, 

 and times of bird attacks upon them. The larger "It may therefore be said that from May to Septem- 

 dragonflies (called also 'snake-feeders,' 'snake doc- ber, in the pond country (of Central France) where 

 tors,' 'Devil's darnin' needles,' 'darners,' 'horse dragonflies are naturally common the Hobby lives 

 stingers,' 'hobby-horses,' ' mule killers,' etc., alas for almost exclusively on the larger species [AtSi/inii/n) 

 popular nomenclature ! ) are familiar to every one as while the swifts eat hardly anything but Aorious. 

 seen in summer, coursing like kestrels the borders of Certain other birds often attack dragonflies, but none 

 ponds, or darting in arrow-like flight above the trees, even for a short lime make them their exclusive diet." 

 Few birds are able to capture these. The Pigeon There is a time however when the fleetest of the 

 Hawk and a few of its congeners seem to possess the dragonflies are at the mercy of their weakest enemies 

 requisite swiftness and ability. On summer evenings —the time of their transformation. Everybody 

 I have watched repeatedly above my father's orchard knows that when young (larvae or nymphs,) they 

 in Illinois a flock of common green darners {onnx Hve in the water, and when grown crawl up a reed, 

 J7tnius)a.nd. a flock of swallows flying together both in- or out upon a bank to transform. The adult dragon- 

 tent upon getting an evening meal (of midges, prob- fly emerges from a rent in its old skin, at first limp 

 ably,) each utterly oblivious of the other's presence. and pale and utterly defenseless. For half an hour 

 But there are weaklings among these insects, the it clings to its support, expanding and drying its 

 damsel-flies ( ' hammer heads,' Agrioiis, etc., ) like the wings and then tests them in a first, short and feeble 

 one in our initial cut. These fly but slowly, keep flight. If this is ended successfully it is soon ready 

 much to the shelter of vegetation and when they to take its chances in the upper air. But chipmunks, 



