NORTH AMERICAN MARSH BIRDS 335 



I went back. Of course, with the method of search employed, one is bound to 

 kick into some of the nests and disturb the surrounding; marsh weed before dis- 

 ■covering them. That a naturally retiring bird should desert under these condi- 

 tions is, of course, not surprising. On at least two occasions, however, I have 

 found nests containing incomplete sets by a lucky glimpse of the eggs through an 

 •opening in the protecting growth above them, while I was still at a considerable dis- 

 tance from them. In these cases, I have turned aside without apparently' noticing 

 the nests, and have left the vegetation absolutely untouched in their vicinity, and 

 yet the result has been tlie same — desertion! 



An impression has prevailed during recent years that these rails 

 have disappeared from the limited area in which they were known to 

 breed, the salt marshes of San Diego Bay between National City and 

 Chula Vista. But Griffing Bancroft writes to me that he took a set 

 of their eggs there on May 21,1922; so it seems that the rails wore 

 not entirely wiped out by the flood of 1919. 



Eggs. — The Farallon rail lays from four to eight eggs. They are 

 ovate in shape and the shell is smooth and slightly glossy. The 

 ground color is creamy white or nearly pure white. They are spar- 

 ingly marked, chiefly at the larger end, with minute dots of browns 

 and drabs. The measurements of 54 eggs average 25.1 by 18.9 mil- 

 Umeters; the eggs showing the four extremes measure 27.6 by 18.5; 

 25.5 by 20.6, and 22.5 by 17.2 milUmeters. 



Plumages. — The sequence of plumages to maturity and the sea- 

 sonal molts and plumages of adults are apparently the same as in the 

 eastern black rail. 



Food. — We don't know very much about the food of this rail, but 

 Mr. Huey (1916) has published the following: 



The nature of the food of these birds remained unknown to collectors for many 

 seasons, until the fall of 1912, when the stomachs of a small series were saved for 

 examination. On close inspection, I found the remains of a species of small "bug" 

 that lives ver\- abundantly on- the salt marshes where the birds were taken. I 

 then gathered a number of these animals and sent them to Joseph Grinnell of 

 the Museum of Vertebrate Zoology, to whom I am indebted for forwarding them 

 to the United States National Museum for identification. The reply was as fol- 

 lows: "They are Isopod crustaceans belonging to the species Alloniscus mirabilis 

 (Stuxberg)." Appearances to the contrary notwithstanding, it's really just a 

 small bug. I believe this to be the chief food of the rails living in the salt 

 marshes of this region, and as nearly all the tidal sloughs abound with these 

 small creatures, the food problem can not be a serious one for the birds. 



Behavior. — These little black rails are so secretive in their habits 

 that they are seldom seen and we know very little about them. Mr. 

 Stephens (1909) "when passing along a broad tide creek * * * 

 saw one crouched in the mud a few feet from the bank. It stood 

 perfectly still, with head lowered, as if expecting to be overlooked." 

 Again he says: 



