Mr Black wall on the Instincts ofBirda. 249 



species, under the like circumstances, always adhere to the same 

 stile of architecture. Thus, some of the smaller birds, which 

 produce a large number of eggs, constantly make the entrance 

 to their nests very narrow, and line the interior with an abun- 

 dance of such materials as conduct heat slowly ; while the ring- 

 dove, which lays two eggs only, forms so slight a structure, that 

 they may be frequently seen through it. The partridge, land- 

 rail, and those birds whose young are able to run almost as 

 soon as they are hatched, generally give themselves very little 

 trouble in providing nests for their progeny ; and some species 

 of water-fowl do not make any, but deposit their eggs in the 

 crevices, and on the projecting shelves and ledges of lofty rocks, 

 or upon the bare ground. The sociable grosbeak builds in so- 

 ciety under a common roof. The pensile, Abyssinian, and 

 PhiUippine grosbeaks construct curious nests, which they sus- 

 pend from the slender twigs of trees, particularly such as grow 

 over water; by this means, securing their offspring from the 

 predatory attacks of their numerous enemies ; and the tailor- 

 bird frames its temporary abode, by sewing two leaves together 

 with the flexible fibres of the plants, and hning the cavity with 

 the lightest and softest animal or vegetable down. 



It is true, that, in preparing their nests, birds occasionally 

 accommodate themselves to some circumstances, and take advan- 

 tage of others, in a manner which seems to indicate a large share 

 of intelligence. The wren, for example, usually adapts the ex- 

 terior of its compact fabric to the situation in which it is placed. 

 When built against a hay-stack, hay is almost invariably made 

 use of, and green mosses, or withered leaves and ferns are em- 

 ployed, as green or the various shades of brown prevail in this 

 vicinity. Nor, let it be imagined that these substances, which, 

 from their contiguity, are often most easily procured, are select- 

 ed as a matter of convenience merely ; for I have known this 

 minute bird bring long pieces of straw from a considerable dis- 

 tance with much toil, and, with incredible perseverance, mould 

 the stubborn material to its purpose, solely because its colour 

 approached that of a garden- wall, a hole in which, occasioned 

 by the giving way of a loose brick, it had chosen to place its 

 nest in. 



