19 



Other things being equal, the more boxes the more birds. 

 But the house wren may be an exception to this rule, as it 

 sometimes is exceedingly quarrelsome. My later experience 

 seems to show that a plethora of boxes makes less trouble than 

 is the case where few are available. Ordinarily, boxes set up 

 100 to 200 feet apart are more likely to be occupied the first 

 year than those situated closer. Later, if these are successful, 

 the number may be increased. 



Bird Houses. 

 The purple martin is the only bird that needs a bird house. 

 It is a waste of lumber to build houses with many rooms for 

 any other bird, as a single pair 

 of bluebirds, swallows or wrens 

 will hold a large, expensive house 

 against all comers except the 

 English sparrow or the starling. 

 The martin is a large, hand- 

 some swallow with pleasant, 

 cheerful notes, and is very de- 

 structive to insect pests. Mar- 

 tins formerly were abundant 

 locally in Massachusetts, but 

 after the introduction of the 

 English sparrow the number 

 of martins and the local- 



FiG. 25. — Martin house, after Trafton. 

 (Courtesy Houghton Mifflin.) 



ities frequented by them 

 diminished rapidly until 

 1904, when cold June 

 storms nearly extermi- 

 nated the species in Mas- 

 sachusetts. Since then 

 their numbers have in- 

 creased very slowly, as 



Fig. 26. — Martin house. 



