NATURAL HISTORY OF THE KING RAIL 



51 



increases rapidly toward the end of the call when the notes run togeth- 

 er. One rail gave 25 distinct jupes in a single series, not including those 

 in the rapid ending which could not be counted. This call carries a 

 greater distance than the mating call and is somethimes answered by 

 a number of other King Rails. It is sometimes used when a bird is 

 startled and occasionally serves as an "all is well" call when a pair of 

 separated birds are reunited. In addition, I have often observed an 

 incubating bird using this call when it w^ishes to be relieved at the nest. 

 The primary advertising call of the King Rail is slower and more delib- 

 erate than that of the Clapper, which is usually more of a rapid 

 chaxj- chac-chac-chac- chac- . 



A call uttered during preni iptial courtship by both the male and the 

 female, but more frequently after pairing, is a soft and rapid tuk-tuh- 

 tuk-tuk-tuk-. This sound reminds me somewhat of the clapping to- 

 gether of the mandibles of the Barred Owl {Strix varia)^ and is sel- 

 dom audible to the human ear beyond 20 or 30 feet. The King Rail 

 uses the "tuk" call as a rallying call or gives it to indicate its position 

 to its mate. 



Display 



The display of the male during prenuptial courtship is relatively 

 simple and consists mostly in walking about with tail uplifted and 

 white undertail coverts extended (fig. 21-1) . In this position the white 

 undertail coverts can be seen from a considerable distance. While 

 flashing its white undertail coverts, the rail usually flicks its tail up 

 and down slightly. Females that I observed during the period of pre- 

 nuptial courtship made no attempt to display. 



There were other forms of posturing during the period of courtship 

 and mating, but apparently the cocked tail and well-exposed white 

 undertail coverts, accompanied by the mating call, are the principal 

 means of attracting a mate. 



On two occasions I observed what appeared to be another form of 

 display, the "pursuit display." The circumstances and the behavior 

 of the male were essentially the same both times. In each case the male 

 apparently had not succeeded in attracting a mate to his territory. On 

 March 1, 1955, at 8 :30 a.m., I saw a small and very rufescent King Rail, 

 later established to be a female, moving along a rice levee bordering a 

 roadside ditch and approaching a calling male. The female continued 

 along the water's edge at a slow but steady gait and passed beyond 

 the male that was standing in the ditch. As soon as she was ahead of 

 him, the male followed her at a fast walk with head and neck out- 

 stretched, bill open (but emitting no sound audible at 40 feet), tail 

 cocked, and white undertail coverts extended (fig. 21-2) . 



Following pair formation much of the posturing and calling that 

 characterized the period of prenuptial courtship continues, at least 



