LIFE HISTORY OF THE QUETZAL—SKUTCH 281 
building a nest near their own. Once while the male quetzal was 
brooding the nestlings, a strange female flew to the doorway, with no 
food visible in her bill. One of the flycatchers gave chase to her, and 
the quetzal, emerging from the nest, also darted at her, but without 
touching her. She flew directly away and I saw her no more. 
Only at the second nest of my second pair of quetzals could I actually 
see the eggs and determine the period of incubation. The nest was 
in a low, rotting stub in a shady pasture beside a little-used pathway. 
I feared betraying its position to passers-by and through an excess 
of caution did not set up a ladder and look in with a mirror until 
I was sure that incubation had begun. At this late nest the birds 
began to incubate on June 24, or possibly even on the 23d, and the nest- 
lings hatched on July 11, giving an incubation period of 17 or 18 
days. This agrees rather closely with the periods available for other 
trogons: 18 or 19 for the Mexican trogon, 19 for the black-headed 
trogon, 18 for the graceful trogon. 
CARE AND DEVELOPMENT OF NESTLINGS 
Like other newly hatched trogon nestlings, those of the quetzal 
bore no vestige of down upon their pink skin. Their eyes were tightly 
closed. Each bore a prominent white egg tooth near the tip of the 
upper mandible, which was slightly shorter than the lower. Their 
heels were studded with the short, papillate protuberances typical of 
nestlings that grow up in a nursery with an uncarpeted floor. When 
I first saw the two newly hatched nestlings, only a few fragments of the 
blue egg shells remained on the bottom of the nest. 
During their first few days of life, the young quetzals were brooded 
much of the time. They were nourished almost if not quite ex- 
clusively with small insects; it was not until later that fruits became 
an important element in their diet. The parents at first kept the 
nest perfectly clean, removing all the droppings, which apparently 
they swallowed, for I saw none carried away in their bills. On the 
nestlings’ fourth morning, I heard their mother scraping and scratch- 
ing in the nest, doubtless to clean it out. This attention to sanitation 
was eventually to be relaxed. Still, quetzals are considerably in ad- 
vance of their relatives in this respect, for the Mexican trogons, grace- 
ful trogons, and Jalapa trogons that I studied did not even remove 
the empty egg shells and the bottom of their nests soon became foul. 
When the nestling quetzals were 2 days old, the sheaths of both 
their contour and flight feathers began to push through their pink 
‘skin. At 4 days, there was slight change, save that the nestlings 
were considerably larger and their feather sheaths somewhat longer. 
When they were 5 days old, their eyelids began to separate. At 8 
days, they could open their eyes, but most of the time rested with the 
