THE BIRD-WATCHER'S GUIDE. 9 



5. Nest-building. — Which sex chooses the site ? 

 Which builds ? If both, state share of each. If hen, 

 what does cock do meanwhile ? AVhat time of day does 

 building take place ? How long does it take to complete 

 the nest ? Detailed description of the bird's method of 

 building (how it starts, fashions the nest, where and how 

 it collects the material). Interval between the completion 

 of the nest and laying of the first egg. Causes of desertion. 



6. Nest. — The material, inside and out (in detail). 

 Is there a laj'er of different material between the inside 

 and outside ? Site of the nest. Is the material of the nest 

 available near the site ? Variation in the nests of the 

 same species building in the same area or the same kind 

 of site. Difference between the first and subsequent 

 nests of the same bird, and between those of young and 

 old birds. Note quarter to which the nest is exposed, and 

 how protected from sun, wind, water, or detection. 

 Note fate of eggs and young in the case of each nest 

 described. 



7. Eggs. — Date and time of day when each egg in the 

 clutch is (1) laid ; (2) hatched, the eggs being numbered. 

 Number in clutch addled. If the eggs are not numbered, 

 the incubation-period should be reckoned from the date 

 on which sitting commenced. Effect of weather and the 

 situation of the nest on the period of incubation. 

 Weight of each egg before incubation. Loss of weight 

 as incubation progresses. 



8. Incubation. — Which sex incubates ? If both do 

 so, their respective shares, and the hours at which they 

 sit. Is the incubating-bird fed ? Her (his) actions 

 when fed. Are the eggs covered when left, and with 

 what material ? Are the eggs turned, how often, and 

 in what manner ? 



9. Nestlings. — (a) A series of specimens or photo- 

 graphs showing the development of the nestling from day 

 to day (all parts of body, pterj^lography, coloration) ; 

 (h) weight of same nestlings from day to day, taken at 

 the same hour ; (c) measurements (^.) from tip of beak to 



