544 LAND ANIMALS 



mountains above 700 m., such pests are not of especial significance, 

 as the unfavorable temperature conditions keep their reproduction 

 within bounds. In the German climate, pure stands of conifers afford 

 the most favorable conditions for the increase of these pests ,on ac- 

 count of the unlimited food supply. 



Pure stands of conifers also favor the increase of those birds which 

 are especially attracted by them, such as the crossbills {Loxia) , the 

 coal-tit and crested tit (Parus ater and P. cristatus) , the golden- 

 crowned kinglet, and the siskin. In Europe these often constitute, 

 with the common chaffinch (Fringilla coelebs) , the entire breeding 

 population. As soon as even a few hardwoods are scattered among the 

 conifers the variety of the bird population increases. 12 Capercaillie, 

 black woodpecker, ring dove, and woodland eared owl are also partial 

 to coniferous forest. The red deer {Cervus elaphus) does not find suf- 

 ficient food in such forests, and if artificially maintained in them, it 

 causes much damage to the timber by barking the trees. 



The difficulties faced by pure stands of timber are further increased 

 when plot culture is carried on. This form of forest management in 

 Germany has brought an enormous increase in the large brown snout- 

 beetle {Hylobius abietis). These beetles congregate in cut-over areas 

 to lay their eggs in the stumps; the larvae develop in the bark 

 of the larger roots, and pupate the following year. On emergence, the 

 beetles then attack the young trees that have been set out in the 

 meantime. The arrangement of breeding place and food supply is thus 

 favorable to this species in the highest degree. Many insects abound 

 in the plantations of young trees, such as the broad-bodied sawfly 

 (Lyda), a number of snout beetles (Pissodes, for example), goat chaf- 

 ers, and many microlepidoptera. Tall stands of fir saplings, by their 

 density, afford shelter to many animals. Such sapling thickets are 

 especially favored by birds for their nesting sites. 



In the eastern United States the rather generally neglected farm 

 woodlots are also rich in animal life. Thanks to their small area, their 

 borders have a relatively great extent, and the conditions of food 

 supply are favorably influenced by the neighboring cultivated fields. 

 These woodlots accordingly resemble the forest islands of a savanna 

 (cf. p. 427). 



Orchards, gardens, and parks. — Whereas the artificial steppe and 

 artificial forest are conspicuous for a fauna poor in number of species 

 though rich in individuals, the gardens and parks, even though in and 

 around towns and villages, are conspicuously rich in species. This is 

 in correlation with the variety of the vegetation and the diversity of 

 aspect of this environment, where the lawns, shrubbery, and groups 



