226 
THE CONDOR 
Vol. XVI 
Plegadis guarauna. White-faced Glossy Ibis. During our stay large 
flocks of White-faced Glossy Ibis were seen both feeding and in flight. The 
numbers appeared to be greater toward the end of our visit. Several of the 
flocks in which the individuals were counted numbered thirty to forty. From 
their actions we inferred that they had not yet begun nesting. 
Shore-birds. — Black-necked Stilts {Himantopus mexicanus) were by far 
the most numerous of all the breeding birds in the vicinity. They nested very 
commonly on muddy islands in the larger ponds ; but nests were also found 
along the margins of ponds out in the brush as well as in flooded fields. In 
such places as last indicated the nests had often been built up so as to reach 
above the surface of the water. It was suggested to me some time ago by Mr. 
Paul J. Pair that Stilts alone among all the water birds, seem to have sufficient 
intelligence to increase the height of the nest in order to keep it from being 
flooded by rising water. Mr. John G. Tyler attests to the same thing. Evi- 
dence which we obtained certainly points in this direction. On the banks of 
ponds and on muddy islands the nests were usually very simple in structure, 
being a hollow in the ground lined with a few weed stems. Many nests found 
above water may well have been of this crude structure before the encroach- 
ment of the water. When seen by us, however, they were well constructed 
nests built up to a height of six to ten inches (see figs. 64, 65). It seems quite 
possible that extra layers of stems could be added to the nest as it and the 
eggs were threatened with flooding by the rise of the water. Two nests in 
which the young were just hatching were noted May 21, but all the rest of the 
nests contained three or four eggs. Fresh eggs were examined on May 22. 
Avocets {Recurvirostra americana) were still more partial to the muddy 
islands than were the Stilts. The former were present in moderate 
numbers, and a nest containing three eggs was found on May 23. 
A downy young one several days old was noted on May 21 swim- 
ming in a shallow pond and turning tail up as it tried to reach 
something on the bottom. Its stomach was found to contain eight or 
more small water beetles (Dytisciclae) , 1 Jerusalem cricket {Stenopelmatus) , 1 
larva of a dragon-fly, 1 small bug {Pentatomidae) , and 1 centipede (Scolopen- 
dra). 
Along the muddy shores of ponds five Snowy Plover (AEgialitis nivosa) 
were seen at different times. Three were noted on May 17. Their light brown 
backs so harmonize with the color of the muddy shores of ponds that it is im- 
possible to see the birds until they move. The stomach of one contained more 
than ten water beetles (Dytiscidae) . These birds were very tame and a photo- 
graph was taken at a distance of eighteen feet. 
A flock of twenty-six Western Sandpipers {Erennetes mauri) was noted 
on May 17 and two Northern Phalaropes {Lobipes lobatus) on May 19. 
Killdeer {Oxyeclius vociferus) nested most commonly on the alkali flats 
away from the water. When one walked across such stretches as many as ten 
of these birds could be seen running along ahead or standing “teetering” and 
incessantly repeating their call. The eggs in one nest found May 15 had been 
broken on the under side, just as if the weight of the bird, pressing the eggs 
against the small pebbles forming the floor of the nest, had crushed in the 
shell. Another nest found on May 15 was unique in the facts that it was 
placed on a small grassy knoll surrounded by water, and that the cavity was 
well lined with short stems of devil grass. A downy young one was found 
May 22. 
