336 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1926 
of the brooks in the deep recesses of the forest. Not a single nest, 
however, was found remote from the water. The large number of 
undisturbed nests of this species was convincing proof that it was a 
most successful type for conditions in the Tropics. 
The nest at the boat landing when found contained two fresh eggs 
of a flesh-ocher ground color with a broad band of ferruginous 
near the larger end. We built an observation blind on the shore 
where we could clearly see the bird as it approached and left the 
nest. After a few visits we were able to ascertain that the upper 
parts of our bird were a greenish olive, the underparts buffy yellow, 
the long tail black, and that there was brilliant sulphur-yellow patch 
on the rump. These characters were sufficient to identify our new 
flycatcher acquaintance as a species of Myiobius, but it was not until 
much later when we collected a specimen that we were able to 
identify it as the black-tailed myiobius (Myiobius atricaudus). This 
bird vibrated its wings so rapidly during flight that it produced a 
buzzing sound not unlike that made by a humming bird when hover- 
ing about the flowers. It was a very nervous creature and left the 
nest on the slightest provocation. Though the bird is completely 
hidden from view when on the nest it was evident that it could see 
us through the weave of nesting materials, and no matter how cau- 
tiously we approached she was quick to leave long before we reached 
the blind. At night she was not disturbed by my presence even 
when I threw on a flashlight to illuminate the nest. All that I 
could see of the bird at such times was her tail. There was not 
room in the small bowl of the nest for such a long appendage, hence 
she was obliged to hang it in the covered passageway while incubat- 
ing the eggs or brooding the young. As is the case with many birds 
in the Tropics, this fly catcher frequently left the eggs for long periods 
of time during the warmer hours of the day, but she always faith- 
fully brooded them at night. As far as I could determine only one 
bird, probably the female, did the work concerned in rearing the 
brood. Only at one time did I see a second bird about one of the 
nests and that was the occasion of a very spirited fight which resulted 
in the visitor leaving at once. To be sure the visitor may have been 
some other than her mate. The quick movements of the bird, com- 
bined with the poorly lighted situation and the dark colors of the 
surroundings, presented a difficult problem in photography. An 
exposure of sufficient length to insure an image always resulted in 
a worthless blur. This difficulty was overcome, however, by using 
light reflected from a large mirror manipulated by Mr. Van Tyne 
from a point across the cove. Satisfactory pictures were then se- 
cured by working the graflex with the stop wide open and with an 
exposure of one three hundred and fiftieth of a second. For the 
