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The nests are great, bulky, untidy masses of straw and grasses and 
the tendency of these birds to fill down-spouts and load with litter every 
projecting architectural feature of buildings makes them objectionable. 
Added to the nesting habits of the House Sparrows, their congregation 
in numbers throughout the whole year in sheltered corners under cornices 
and porches causes accumulations of filth that is exasperating to the house- 
holder. Today one of the important problems in architectural offices is to 
design satisfactory detail that will not harbour Sparrows, whose dirt dis- 
figures the most careful design and disintegrates the material of which 
the building is composed. 
Without doubt the introduction of the House Sparrow into America 
was a mistake. It was known in its original home as a rather undesirable 
species and unfitted for the work it was brought over to perform. In this 
country, removed from the natural checks that kept it under control, it 
has multiplied beyond all reason and though its objectionable features 
have increased, its commendable ones have not. However, the House 
Sparrow is here to stay. It has been legislated against, and large sums 
have been spent in the attempt to control it, but without avail. Local 
endeavour reduces the number from time to time, but only to have new 
hordes pour in from surrounding country when the effort has spent itself. 
Constant endeavour will keep the numbers reduced, but only continent- 
wide persistent effort will destroy the species altogether. Traps, poison, 
and systematic destruction of the nests are the most satisfactory means 
of control. Poison is effective, but care must be taken that it is used only 
in the seasons and places where no other species have access to it. Wire 
fabric traps that are always set and will catch numbers at a time are the 
most satisfactory. A good type of such trap has been described by the 
United States Biological Survey in Farmers' Bulletin 1$3. 
The common use of the automobile and the reduction of the number 
of horses on our streets and roads have given the first real check that the 
species has received in this country since it was introduced. In consequence 
of the reduced food supply, especially in winter, the number of the species 
is considerably less than it was a few years ago, and it seems as though this 
unexpected factor has done more to keep the House Sparrow within bounds 
than all the fulminations that have been directed against it. 
521. Red Crossbill. American crossbill, crossbill. Loxia cwrvirostra. L, 6*19. 
A small or medium-sized Sparrow with the bill tips prolonged and crossing each other when 
closed (Figure 261). The male is dull red, brighter on rump; females and juveniles 
similar, but the red replaced by greenish or yellow. No wing-bars. Many mixed and 
intergrading plumages between the green and red are to be met with; the red may vary 
from yellowish orange to pure brick red, and a series of specimens may show a bewildering 
array of different shades and tints. 
Distinctions. The crossed bill is distinctive of the Crossbills; the lack of white wing- 
bar designates this species. 
Field Marks. Small birds usually in winter, often in large flocks, some individuals 
showing red coloration. Notes somewhat similar to those of Goldfinches. Climbing, 
almost parrot-like, habits. 
Nesting. Usually in coniferous trees; nest of twigs and grasses lined with moss and 
rootlets. May nest almost any month of the year from January to September. 
Distribution. Europe, northern Asia, and northern North America. In America, the 
coniferous forests across the continent, south in the western mountains to Mexico. Mi- 
grates irregularly south in winter. 
SUBSPECIES. The American Crossbill, occupying most of North America and all 
of Canada, is Loxia cwrvirostra minor. Other forms have been described from the west, 
but have not as yet been recognized in the Check-list. 
