NATURAL HISTORY OF THE KING RAIL 



67 



The young bird loses weight throughout the first day of life. One 

 female chick weighed 16.3 grams at hatching, 16.0 grams at 1 hour, 

 15.7 grams at 2 hours, and 13.2 grams at 24 hours (table 11). 



One to thirty days 



During the first month of life the major change in the appearance 

 of the King Rail chick is one of size and conformation (fig. 27). A 

 young captive male weighed 16.7 grams when he was I/2 days old, 

 and 96.3 grams when he was a month old. His measurements at I/2 

 and 30 days, respectively, w^ere : exposed culmen, 11.0 and 28.0 mm. ; 

 tarsus, 20.0 and 42.0 mm. ; middle toe with claw, 22.0 and 50.0 mm. 

 (table 11.). 



The thick natal down is present during most of the first month, 

 but during the fourth week there is evidence of development of the 

 juvenal plumage. 



Table 11. — Growth of four King Rails 



Length of— 



Weight 



Age (grams) Exposed Middle toe Tarsus 



culmen with claw (mm.) 

 (mm.) (mm.) 



Bird A: 



Hatched 1 16. 3 



1 hour 16. 0 



2 hours 15. 7 



Iday 13.2 11.0 20.0 20.0 



8 days 14.0 12.5 26.0 21.5 



21 days 40.0 19.5 36.0 29.0 



60 days 202.0 40.0 57.0 53.0 



90 days 265.0 49.0 57.0 53.0 



Bird B: 



1 day 15. 6 



7 days 18. 9 



17 days 37.0 20.0 



21 days 50.7 



30 days..- 75.4 25.0 42.5 38.5 



45 days. 177.9 40.0 49.0 52.0 



Bird C: 



l^days 16.7 11.0 22.0 20.0 



7-8 days 25.7 



17-18 days 46.5 21.0 36.0 32.0 



21 days 63.8 



30 days 96.3 28.0 50.0 52.0 



45 days.. 219.8 40.0 61.0 56.0 



60 days 327.0 48.0 61.0 58.0 



Bird D: 



m days 15.6 



7-8 days 19.7 



17-18 days 32.0 



21 days 47.7 



30 days 70.8 25.0 43.0 36.5 



45 days . 176.0 - 



60 days 258.6 



I Wet. 



Toward the end of the first month the young rail begins walking 

 more deliberately and assumes the gait of the adult bird. When it is 

 seeking food, it tips its tail in typical adult fashion. Tail tipping was 

 observed in one 2- week-old chick. 



