408 RELATIONS OF BIRDS TO AGRICULTURE 



of nesting, incubation, brooding. (6) Season of flocking, if at all. 

 (7) Songs at different seasons. (8) Enemies and tragedies. (9) 

 Habits of flight. (10) Migration. (11) Variations in color due 

 to age and season. (12) Differences in marking due to sex. (13) 

 Bird census for different kinds in the community. (14) Habits 

 with reference to proximity of water. (15) Other points. 



How to Attract Birds. Allowing that birds deserve our pro- 

 tection, one naturally asks, What can we do to draw them about 

 us? Trees and shrubbery, of course, attract them. U. S. Farmers' 

 Bulletin 621 gives a list of about eighty trees or shrubs whose fruit 

 affords food to birds. Some of these should be on every one's 

 grounds. 



The establishment of bird refuges and game preserves is doing 

 much to conserve bird life. 



The artistic bird houses now on the market are a help in this 

 direction. These are constructed not only for bluebirds, wrens, and 

 martins, but also for nut-hatches, woodpeckers, and other species. 

 An ingenious boy or man can easily construct houses which answer 

 the requirements very well and at but little expense. 



Bird Houses. In passing, it may be well to state a few very 

 necessary facts about bird houses known to many, but not all. 

 Wren houses should be free from the preceding year's litter before 

 one can expect them to attract newcomers. If the entrance to a 

 wren house is the size of a silver quarter, it will admit the wren 

 but keep out the European or English sparrow. Martin houses 

 should be placed on high poles or in conspicuous places where the 

 martins can see them, not too near to trees. A weather-worn 

 martin house is apparently more attractive to these birds than a 

 newly painted domicile. 



The Brush Hill Bird Club, of Milton, Mass., has published the 

 following directions relative to the construction of bird houses: 



"Bluebirds and Tree Swallow. Box, 12 X 6 X 5 inches; size 

 of hole, 1J/2 inches; height from ground, 8 to 30 feet. 



"Wrens and Chickadees. Box, 12 X 5 X 4 inches; size of hole, 

 \Y inches; height, 6 to 25 feet. 



"FlickersBox, 15 X 10 X 8 inches; hole, 3 to 3^ inches; 

 height, 6 to 25 feet. 



"Screech Owl Box, 15 X 12 X 12 inches; hole, 3 to 3^ 

 inches; height, 15 feet. 



"Martin House Colony. Holes, 2 inches; pole, 16 to 20 feet 

 high in open spot where martins can easily see it. 



