120 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



getic creatures strive to fill the container they select with nesting ma- 

 terial. Regardless of its size it is usually well filled except for a nar- 

 row passageway leading to the comparatively small nesting cavity 

 that contains the eggs or young. This trait is probably one that has 

 developed through the protection the birds derive by keeping out cer- 

 tain intruders. This fact is often considered in the construction of 

 wren nesting boxes by cutting an entrance large enough to admit the 

 tiny body of the wren but too small to admit the passage of competi- 

 tors the size of an English sparrow or a starling. 



The bulk of a house wren's nest is generally composed of relatively 

 long and coarse twigs and sticks and grass. According to Godard 

 (1915) if the wrens are given a choice of dry and green sticks they 

 select the dry dead sticks and reject the green ones. The nesting cavity 

 is usually lined with finer and softer materials such as feathers, hair, 

 wool, spider cocoons, and catkins. 



McAtee (1940a) analyzed the materials in 33 complete or partial 

 nests found at the Bureau of Plant Industry Experiment Station lo- 

 cated near Glen Dale, Md. His report is as follows : 



Foundations included (in the number of nests indicated) : twigs (33), 

 feathers (16), chestnut spikes (13), wool (12), leaves (7), cord (6), and weed 

 stalks (5). Materials used in fewer instances were: rootlets, red-cedar bark, 

 cotton, grass, chestnut shell, paper, a large fragment of snail shell, exoskeletons 

 of milleped and sowbug, and a spider cocoon. The twigs were characteristi- 

 cally coarse and included some up to 8 inches in length and a few that were 

 branched. Rose twigs with plentiful thorns were frequently employed, and in 

 a few cases callow young were raised in such nests with little or no cushioning to 

 protect them from the spines. The twig bases of nests were often from 4 to 6 

 inches deep. Flecks of wool and cotton were scattered through the twig bases 

 to no conceivable purpose. The lining of the 33 nests included grass in 19 cases, 

 hair, chiefly horsehair, in 16, feathers in 13, and rootlets in six. Other items 

 were red-cedar bark, chestnut spikes, weed stalks, and grass. The material in 

 one nest, loosened up in the process of analysis, filled a 2-gallon bucket. 



The house wren may use other than the traditional nesting materials. 

 Mrs. Gilbert Drake (1931) describes a nest built in a chicken house in 

 West Park, N. Y., that consisted largely of small pieces of rusted 

 chicken wire. A nest observed by Helen P. Williams ( 1931) was made 

 up entirely of metal consisting of rusty bent nails, double-pointed 

 tacks, and pieces of wire. An analysis made of a nest found at Ames, 

 Iowa, by Harriet C. Battell (1925) was made up of the following rub- 

 bish : "52 hairpins, 68 nails (large) , 120 small nails, 4 tacks, 13 staples, 

 * * * 10 pins, 4 pieces of pencil lead, 11 safety pins, 6 paper fasten- 

 ers, 52 wires, * * * i buckle, 2 hooks, 3 garter fasteners, and 2 

 odds and ends." Goelitz (1918) reports finding a nest made up 

 entirely of rusted pieces of wire. In fall a tangle of rusted chicken 

 wire was thrown behind a shed, and the following spring a pair of 

 house wrens in search of nesting material found that the wire would 



