How to Study a Bird 183 



12. Tools. — Are they ever known to use a tool, that is, a stub, a stone 

 or other foreif^n object, to help the beak or claws ? 



13. Success in Life. — Can it hold out against the English Sparrow ? If 

 so, what is its peculiar strength? Is the species increasing or not with 

 civilization ? How does it adapt itself to changing conditions, such as 

 deforesting, increasing human population ? 



14. Summer Roosts. — Does it form summer roosts ? If so, does it use 

 these in common with other species ? 



15. Constancy. — Does the same pair return each year to the same local- 

 ity ? This can be settled only by marking them in some way. 



16. Food. — Does it feed on the wing, under water, on tree-tops, by 

 night ? Does it regurgitate pellets ? Does it distinguish poisonous plants 

 and insects ? Does it teach its young to do so ? Does it feed the young 

 by regurgitation ? Does its food change with time of life ? Does it eat 

 food that would poison another species ? Do certain foods influence the 

 bird's color ? Does it store up food ? Does it treat special foods in special 

 ways, thus, put very hard seeds to soak, or remove the stings of wasps, or 

 the wings of moths ? Does it take food with it claws ? 



17. Plumage. — Particularize each specimen in form, color and measure- 

 ment, noting difference of sex, season, age, moult and locality. Thus, do 

 heavily marked specimens characterize a certain locality? and so on. Do 

 young or old moult first ? Do sick or healthy moult first ? 



18. Mating. — Note fully any courtship observed, with maneuvers of 

 both birds or competitions with rivals; is it ever polygamous or polyan- 

 drous ? Do the same birds remain paired throughout the season, or for 

 more than one season ? 



19. Nesting. — Which of the pair selects the nesting site? Give full 

 particulars of construction, materials, proximity to the ground and to the 

 water, of each nest; preserving, photographing or sketching the same, and 

 observing whether covered over or approached by a covered way. Does it 

 shape the nest with bill, claws or breast ? Does it line the nest with its 

 own feathers ? Does it show preference for any kind of lining or building 

 material ? Does it ever evidently go a long way to get certain material 

 while others are close at hand ? Is the same nest ever used twice ? How 

 does it clean the nest while in use ? Does it use mud for building ? Does 

 it steal nesting material from other birds ? 



20. Eggs. — Give details of laying, time between each oviposition, varia- 

 tion of the eggs in size and color, stating whether those first laid are large 

 or more heavily marked than those laid later; are the eggs turned daily, 

 and, if so, by which bird ? Is the first clutch of eggs more numerous than 

 others of that season ? Are young birds more prolific than older ones ? 



21. Broods. — Number per season ; average of each? Are later broods 

 less ? How long is each cared for by the parents ? Is the female first to 



