45 



tent caterpillars. Mr. Lord refused permission to have the trees 



on his estate cut, as he had been attracting birds about the 



place and desired to raise wild cherries as food for them. The 



caterpillars did very little harm on 



his estate. In the fall of 1913 many 



tent caterpillar moths had laid their Eggs of the tent ^~^ moth , an 



eggS On his trees, but m late No- enemy of the apple tree, eaten by 



, , , chickadees and blue jays. 



vember when he examined the trees 



he found that the birds, mainly chickadees, had removed nearly 



all the egg clusters. 



Baron Hans von Berlepsch experimented for many years with 

 methods for attracting birds at his estate in Thuringia by 

 means of nesting boxes, food plants and bird food. He thus 

 increased enormously the number of birds on his estate. The 

 practical value derived from the insect-eating habits of his 

 birds was shown in the spring of 1905. 



The Hainich wood, south of Eisenach, which covers several 

 square miles, was entirely defoliated by the caterpillars of a 

 little moth (Tortrix mridana), but the woods on the near-by 

 estate of Baron Von Berlepsch were left entirely untouched by 

 the caterpillars, so that they actually stood out from the sur- 

 rounding barren leafless woods like a green oasis in the country- 

 side. At a distance of a little more than a quarter of a mile 

 from his estate the first traces of the plague were apparent, and 

 half a mile away it was in full force. This plainly showed how 

 far the birds from his estate had traveled to find food. 1 



Similar observations were made during a plague of the same 

 caterpillar in 1906 in the Crown Wood Harras, in the Grand 

 Duchy of Hesse, where the protection of birds had been carried 

 on energetically for a few years; also the abundant use of 

 nesting boxes in the Prussian woods at this same period brought 

 about a marked decrease in at least two species of destructive 

 insects. 



BIRDS AS WEED DESTROYERS. 



Fighting weeds occupies about 30 per cent of all the time a 

 farmer spends in cultivating his crops, according to experts of 

 the United States Department of Agriculture. Birds assist the 



1 Hiesemann, M.: How to Attract and Protect Wild Birds, London, 1912, pp. 50, 51; 

 translation by Emma S. Buchheim. 



