FROGS AND BIRDS 105 



Other incidents in the course of nest-building, incubation, 

 and care of the young birds will certainly be noted if sufficient 

 observation to answer the above questions is given. Attacks 

 by cats and bluejays (fig. 45), disputes between the parent 

 birds, accidents from high winds or other causes are all 

 likely to enter into the course of nesting. And the behavior 

 of the parent birds under such more or less unnatural cir- 

 cumstances will be interesting to observe and record. 



While some pupils are watching a robin's nest others 

 should observe the nesting of other kinds of birds — the blue- 

 bird, wren,, groundbird, catbird — ^any familiar kind that 

 can be found at work. 



See Chapters XVII-XXI in Baskett's "The Story of the Birds," 

 and Chapter VI in Chapman's "Bird-life." 



