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AMERICAN FORESTRY 



with warblers, all of which were very caterpillars is recounted by America's 

 busy with the trunks and branches, foremost Ornithologist, Robert Ridgway. 

 * * * We have practically no forest "We first noticed the caterpillars 



tent-caterpillars. * * * They hatched something like two weeks ago, our 

 in large numbers, but the cold evidently attention being attracted to them by 

 killed many, and the birds appeared to noticing several branches which had 

 have cared for the remainder." been stripped of their leaves. We then 



discovered the cat- 

 erpillars in clusters 

 on the twigs and 

 foliage and a little 

 later a compact mass 

 of them, about a 

 foot long by 6 inches 

 wide, on the bark 

 of the trunk, a 

 foot or so from the 

 ground. Within a 

 day or two of our 

 first discovery of the 

 pests, we saw a 

 yellow-billed cuckoo 

 in the tree, busily 

 engaged in eating the 

 caterpillars. Later 

 this was joined by 

 another (probably 

 the mate) which, 

 however, only made 

 occasional visits to 

 the tree, its time be- 

 ing doubtless mainly 

 occupied with incu- 

 bating or brooding. 

 The other cuckoo 

 practically lived in 

 the tree, being very 

 seldom absent, even 

 for a short time, 

 and was so persis- 

 tent in his destruc- 

 tion of the cater- 

 pillars that whenever 

 one fell to the ground 

 he would immediate- 

 ly follow it and then 

 dispatch and devour 

 it; and later when 



Black-Capped Chickadee and Brown Creeper 



the chickadee on the upper branch and the creeper on the trunk 

 of the tree are among the most important of the insectivorous 

 birds. they climb over trunks and branches scanning every 

 inch of the surface for insects that are concealed in the bark 



All of the caterpillars mentioned 

 above are hairy kinds, which, it is often 

 asserted, are avoided by birds. The 

 evidence makes it clear, however, that 

 this is not always the case. Cuckoos 

 in particular are fond of these hairy 

 larvae. How a pair of cuckoos extir- 

 pated a colony of destructive walnut- 



few were left on the 

 tree we saw him carefully searching 

 the ground beneath. The resiilt of the 

 work of these two cuckoos (principally 

 one of them) was that within a week 

 the colony of caterpillars was absolutely 

 exterminated, and I have not been able 

 to find one in the neighborhood." 

 (July 30, 1906.) 



