336 BOARD OF AGRICULTURE. [Pub. Doc. 



Recapitulation and Conclusion. 



It is to be regretted that it is impossible, because of lack 

 of space, to present in this brief paper more than a few of 

 the carefully recorded facts, through a comparison of which 

 the following conclusions have been reached, and it is hoped 

 that another opportunity for publishing at least a part of 

 these recorded observations may offer. 



To recapitulate : — 



1 . The widely accepted belief that hairy caterpillars have 

 immunity from the attacks of birds (excepting only the 

 cuckoo) is erroneous. 



2. This error has arisen partly from a lack of painstaking 

 observation, partly from the inadequacy of stomach exami- 

 nations alone to determine the full value of many birds in 

 this respect, and partly from the well-known partiality evinced 

 by many birds for smooth-skinned caterpillars. 



3. During most of the time when the young birds receive 

 their food from the parents they require a great quantity of 

 animal food, which consists mainly of caterpillars and other 

 soft-bodied insects. 



4. The parent birds, being overworked at that season in 

 defending their young from many enemies and in providing 

 sufficient food both for themselves and ^^oung, take such cat- 

 erpillars as are most plentiful and readily obtained. 



5. The most destructive hairy caterpillars are gregarious, 

 and many of them reach their maximum of destructiveness 

 usually when many of the young birds are in the nests. 

 The presence of these caterpillars is marked by the evidence 

 of their destructiveness. Their presence is readily detected 

 at a distance by birds, which visit places where such food 

 can be readily obtained in quantities. About forty species 

 are known to visit such places, feeding largely on the cater- 

 pillars, while many of them take them to their young. When 

 the young are fledged they are led by the old birds to such 

 localities and taught to feed themselves. 



6. An abundance of smooth-skinned caterpillars, which 

 many birds prefer, tends to limit the destruction of hairy 

 caterpillars by birds. 



