NATURAL HISTOiRY OF THE KING RAIL 



97 



Clutch size is large, averaging 10 or 11 eggs. There appears to be 

 no geographic variation in clutch size. 



Nesting success appears to be high in most areas. In one Arkansas 

 sample, success was 75 percent; and in one Iowa sample it was 67 

 percent. Such success is probably due in some measure to the incu- 

 bating birds' pugnacity toward would-be offenders. Survival of young 

 until 2 weeks of age was about 50 percent in the Arkansas rice belt. 



Downy young of the King Kail are black. A change from the downy 

 plumage begins at about 1 month. Juvenal plumage is obtained in 

 about 60 days, and wings are developed enough for short flights after 

 the ninth week. 



Usually chicks are more than 1 hour old before they can go over 

 the nest and return. During the first month six different calls were 

 recorded. 



The King Kail occurs in a wider range of habitats and feeds on a 

 greater variety of foods than most other North American rallids. 

 Aquatic animals, particularly crustaceans, are its main food. Plant 

 food items are taken more under emergency conditions. When the 

 King Kail occurs in the same environment as the Clapper Kail, it may 

 subsist mostly on a 1-item diet like that species. 



In most areas King Kails feed mainly in shallow water where the 

 depth is usually 2 or 3 inches. In Delaware Bay marshes. King Kails 

 fed almost entirely on mud flats, exposed at low tide, and on the 

 Arkansas Grand Prairie, in summer, they fed almost exclusively in 

 ricefields. 



In some areas King Kails were observed to have feeding territories 

 to which they returned regularly at times other than the breeding 

 season. 



Most food items are ingested whole, but larger crustaceans often are 

 dismembered before eating. 



Mortality of King Kails apparently is due mainly to birds coming 

 in contact with manmade objects, and to natural predation, especially 

 the destruction of eggs by raccoons. Studies to determine the effects 

 of pesticides on this rail have not been made; however, its favorite 

 food, aquatic animal life, is highly susceptible to these chemical agents. 

 In at least one intensive agricultural area, the Arkansas rice belt, 

 where ecological conditions have not changed during the last 20 years, 

 the King Kail has shown a marked decline. 



The King Kail is one North American game bird that certainly is 

 not overhunted. This is so primarily because the population is gen- 

 erally scattered and its habitat is usually difficult for hunters to work 

 through. The only time that I found them concentrated and fairly 

 easy to shoot was during the harvest in the Louisiana ricefields. A 

 few are shot incidentally in the course of hunting Sora in the Middle 

 Atlantic States, and Bobwhite in the deep South in damp piney woods. 



