THE SAN JOAQUIN VALLEY 293 



two days, May 23 and 24th. When we returned on June 15, 

 to remain until the 20th, we were much disappointed to find 

 that places where birds had been most abundant in May, 

 were now virtually deserted. 



The birds had not finished nesting, but the withdrawal of 

 the water had deprived them of its protection. Their nest- 

 ing sites were no longer islets and had possibly been raided 

 by coyotes. The' spot, although green with the vegetation 

 due to irrigation, was slowly being reclaimed by the desert, 

 and the birds had sought new and more favorable resorts in 

 those portions of the marsh then being irrigated. 



Evidently the abnormal and sudden rise of the water, as 

 well as the equally unusual fall, prevents many birds from 

 rearing young. I found numbers of flooded nests in May, 

 which had been built when the water was still rising, while 

 its disappearance must have been even more disastrous. 



Great Blue Heron in Irrigation Ditch 

 These birds were unusually tame within the Los 

 Banos town limits, and could be photographed by 

 the roadside from a carriage in passing. 



