NATURAL HISTORY OF THE KING RAIL 



65 



remain in the nest, disintegrate, and eventually filter down into the 

 base of the nest. Shell fragments are found in virtually all nests that 

 have hatched young. 



A pair may remain with their brood for more than a month after 

 hatching. I have collected three-fourths grown young rails that were 

 still traveling with an adult pair in August. In one instance a pair, 

 one of which was marked, and their 3 -day-old young still spent most 

 of the day within 20 yards of their nest, and 19 days later were seen 

 only 10 yards from the nest ! Once I came upon a brood of young King 

 Eails approximately 3 weeks old traveling with three adult birds. 



The call given by an adult with young chicks when all is well is a 

 soft continuous woof-woof-iooof- (corresponding to the cluck-cluck- 

 cluck- of a barnyard hen). An alarmed parent with brood emits a 

 sharp gip-gip-gip-^ which causes the yomig to scatter to a hiding 

 place. 



NESTING SUCCESS AND SURVIVAL 



In Clay County, Iowa, Tanner and Hendrickson (1956, p. 55) found 

 that four of six observed nests hatched one or more eggs each. Of 60 

 eggs in the six nests, 39 hatched. 



Of 16 Arkansas nests I observed, 12 hatched one or more eggs each. 

 The average number of eggs hatched in each of these 12 nests was 9.9. 

 Of a total of 147 eggs in all 16 nests, 119 hatched. 



An index of survival based on the number of young over 2 weeks 

 of age is difficult to obtain because complete broods are not always 

 seen. In Arkansas, I observed 10 broods with what I believe were full 

 complements. In each observation, the parent birds were unaware of 

 my presence as the family was crossing a road, feeding in a newly 

 sown ricefield, or moving about in some other comparatively open 

 spot. The number of young per brood ranged from two to nine and 

 averaged five. If my estimate of an average hatching success of 9.9 is 

 correct, then survival rate until 2 weeks of age was about 50 percent. 



BREEDING STATUS OF FIRST-YEAR BIRDS 



Although I know of no example of juvenile or immature birds being 

 marked and recaptured in breeding condition or in the act of nesting, 

 I collected a nesting bird in what appeared to be first-year plumage in 

 the Delaware Bay marshes. Only the lower throat and upper breast 

 regions of this bird were cinnamon, a wliitish area covered most of the 

 lower breast and axillary regions, and the side of its head was con- 

 siderably paler than average for mature birds. The greater coverts 

 were heavily barred with whitish subterminal bars. The specimen, a 

 female, was extremely small. Measurements were as follows (with 

 adult female average in parentheses) : Wing 147.0 mm. (154.3) ; ex- 

 posed culmen 54.0 mm. (61.9); tarsus 50.0 mm. (54.0). 



