2830 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1946: 
the one arriving might fly up in front of the doorway, but always veered 
aside and went to a perch when it saw that the hole was occupied. 
This move usually caused the other to quit the eggs. At times, the 
new arrival would fly up to the doorway in this fashion with no 
previous announcement of its presence. Each of the males, but 
especially that of the second pair, was sometimes guilty of calling his 
mate from the eggs, then flying off with her as she departed, leaving 
the nest unattended until either he or she returned to take charge of 
them. The female more rarely did the same thing. Thus there was 
no set ceremony of nest relief. Less closely synchronized than mated 
birds of many other kinds, one of the pair might come before the mate 
was ready to go; or one would go before the other was ready to come. 
Yet in spite of inconsistencies, they managed to get through their 
three-shift day without leaving the eggs exposed for many minutes. 
After incubation had well begun, the nest was rarely left unattended 
for more than half an hour at a stretch, although once both members 
of the pair at nest 1 were absent for 67 minutes, and on another occasion 
for 51 minutes. 
For many kinds of trogons, the entry into the nest is a very pro- 
tracted procedure. They cling before the doorway, peering cautiously 
from side to side, often for several minutes, before slipping inside. 
If they espy something that excites their suspicion, they dart away to 
return a little later and go through the lengthy performance again. 
The quetzals entered in a less hesitant fashion, often hardly delaying 
in front of the doorway, or at most making only a brief survey from 
this position. 
Upon quitting the nest, the male, as already recorded, would some- 
times rise into the air in a flight display, shouting as he went. I saw 
one of the males do this six times, the other thrice. These spectacular 
flights were made at any hour of the day; one of the males left the nest 
in this manner when his mate relieved him at sunset. Even when 
frightened from the nest by a passing man, the reckless bird might 
soar up and make himself conspicuous to all the neighborhood. Or at 
times he would give loud calls as he flew off, without rising above the 
trees. 
While I watched them, the quetzals were not often called upon to 
drive intruders from the vicinity of their nests. On April 10, not long 
after they began to incubate, male and female of my first pair joined 
in giving chase to a trespassing female of their kind. Later, I saw 
this male pursue a blue-throated toucanet (Aulacorhynchus caeruleo- 
gularis), which would have enjoyed eating their eggs, and twice a 
tityra (Tityra semifasciata), which seemed to be prospecting for a 
nest cavity in the same trunk. Another pair of quetzals was worried 
by a pair of sulphur-bellied flycatchers (Myiodynastes luteiventris) 
