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SPRING 



a thick felt of dry mosses, and occasional patches of heather. 

 Among the oak-scrub which forms a large part of the copse- 

 wood there are many old hollow stumps ; and the holes in 

 them are tenanted by three or four kinds of tits, which can 

 find very little accommodation in the more luxuriant copses, 

 where almost all the wood is too small and too sound for 

 their purposes. Great, blue and coal tits' nests are fairly 

 common in the old oak stumps, and the marsh-tit sometimes 

 builds in them also. The marsh-tit 

 often prefers to bore its own hole 

 for itself in crumbling wood, or 

 sometimes in the dry earth round 

 the roots, like a mouse, though the 

 other three species occupy existing 

 crevices. Willow-wrens are also 

 very fond of these dry copses ; they 

 form cell-like nests in the carpet of 

 moss, or build them among the tufts 

 of heather. About the middle of 

 May the foliage of the trees in the 



MARSH-TIT ' _ & 



copses begins to abound with the 

 caterpillars of several common geometer moths, and other 

 varied species ; and from this time until midsummer we see 

 the tits turning nimbly with their hard seed-eating beaks to 

 the work of caterpillar catching. Caterpillars are the chief 

 food of their numerous young ; but the thousands of larvae 

 thus destroyed make no visible impression on the multitudes 

 still thronging the leaves. The tits and other foraging birds 

 preserve the balance of nature, and that is enough. But some- 

 times the pest outstrips all their efforts. The minute grubs of 

 the little green oak moth sometimes strip the crowns of the 

 standard oaks in dry seasons, so that by the beginning of June 

 they look as if they had been scorched with fire. With this 



