Page:Condor18(2).djvu/22

 60 THE CONDOR Vol. XIIl it over, inch by inch. This is accomplished by a careful swing of the foot, which at first is exceedingly tiring, but which grows comparatively easy as practice makes it a mechanical action. One thing is interesting as a side light on this bird's shyness, a habit that is a constant aggravation to the collector. This is the astonishing ease with which the birds bring themselves to abandon ineomplete sets when they are discovered. Although I have found several incomplete sets, I have in no instance succeeded in collecting a full set from the nest at a later date. In every ease the bird had deserted when 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 discovering them. That a naturally retiring bird should desert under these conditions 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 notie- Fig. 25. A FARALLON IAIL IN ITS SALT MARSH HOME; PHOTOGRAPH OF A chrIYE ing the nests, and have left the vegetation absolutely untouched in their vicin- ity, and yet the result has been the same--desertion! 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 very 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 Museurn of Vertebrate Zoology, to whom I am indebted for forwarding them to the United States National Museum for identification. The reply was as follows: "They are lsopod crustaceans be- longing to the species Alloiscus nirabilis (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. Several collectors have spoken to me in regard to the migration of these