398 USEFUL BIRDS. 



All the rooms will be backed by this, and the pole will go 

 into it. The pole may be made to go into a socket in the 

 ground, and then both pole and house may be taken down 

 in the fall and kept under shelter until the Martins return in 

 the spring ; or, if the pole is hinged near the bottom, the 

 box may be still more readily taken indoors. This will 

 prevent the Sparrows from intrenching themselves within. 

 If a cedar pole is used, the bottom should be well tarred 

 wherever it comes in contact with the ground. It should 

 be set deep in the ground to give it the requisite firmness. 

 If the nests of Martins are dusted occasionally with fresh 

 insect powder, it will relieve them of the vermin which 

 always congregate in large, occupied bird houses. 



Furnishing Nesting Material. 



An abundance of suitable and easily accessible nesting 

 material may cliiefly influence some birds in choosing a site 

 for a home. 



It is now believed that the Parula Warbler breeds only 

 where the usnea moss grows luxuriantly, for in this moss she 

 usually secretes her nest, constructing it largely of the same 

 material. Kobins, Swallows, and Phoebes must have mud for 

 nest building. The Chipping Sparrow lines her nest with 

 hair, usually that of the horse, cow, or deer. Vireos and 

 Orioles must have hair or strands of some kind to construct 

 the pendent fabrics which they skillfully weave. If we hang 

 nesting materials on bushes, trees, or fences, or place them 

 on the ground in the open, where birds will be in no danger 

 from cats while securing them, this may prove to be the final 

 " straw " which will decide several pairs of l)irds to nest on 

 our premises. Such supplies, when watched, furnish ready 

 means of tracinof the nest builders to their nests. We can 

 then take means to protect the nests from marauders. Root- 

 lets, fibers of birch, cedar or grape vine bark, straw, fine 

 hay, hair, feathers, thread, twine, rope yarn, jute, sphag- 

 num moss, — all will serve a purpose. It is important to 

 furnish twine, hemp, yarn, or some similar material for the 

 Orioles ; otherwise they may get it by tearing to pieces the 

 nests of other birds which have used such materials. In 



