636 THE WILSON JOURNAL OF ORNITHOLOGY • Vol 123, No. 3, September 2011 
FIG. 1. Four nests of the Scintillant Hummingbird built one on top of the other at La Colmena. Coronado. San Jose 
Province. Costa Rica. The nest order is from left (first) to right (fourth) The arrow shows the egg shell in the second nest. 
(Photograph by Luis Sandoval). 
Notable examples of nesl reuse occur in raptors 
(Falconiformes, Aecipitriformes) and storks (Cic- 
conidae). Many species from these groups can 
reuse the same nest in successive years and even 
add new material each year, which increases nesl 
size (Dijak et al. 1990, Cezilly et al. 2000. 
Vergara et al. 2006. Stout et al. 2007). Nest reuse 
by hummingbirds has been reported previously 
(Skutch 1973). but only in North American 
species (Gault 1885. Baltosser and Scott 1996, 
Baltosser and Russell 2000). We provide another 
example of nest reuse behavior with the first 
report of a multi-season nest reuse by the 
Scintillant Hummingbird (Selasphorus scintilla). 
This hummingbird is a common endemic of Costa 
Rica and west Panama, occurring between 900 
and 2,100 m asl. Nests of this species are usually 
in bushes at forest borders or in open areas (Stiles 
and Skutch 1989). 
OBSERVATIONS 
We found an empty Scintillant Hummingbird 
nest at La Colmena. Vasquez de Coronado, San 
Jose Province. Costa Rica (09 59' N, 83 59' W; 
1,500 m asl.) on 15 March 2010. The site borders a 
small secondary forest patch between farm fields 
and isolated houses. 
The nest was a multi-cup structure (Fig. 1) 
attached from the bottom to the base of a light 
bulb 2.5 m above ground on a residential porch. 
The nest was comprised of four similar nest cups 
with newer nests on top of the older ones. The 
outer layer of the four individual nests consisted 
of mosses, lichens, and spider webs. The inner 
layer was composed mainly of Asteraceae seeds. 
These characteristics are in agreement with 
previous nest descriptions of Scintillant Hum¬ 
mingbirds (Stiles and Skutch 1989). There was 
little variation between the diameters of the nest 
cups (CV = 16%). in comparison to variation 
found in nest height and depth of the egg chamber 
(CV = 145 and 87%, respectively, Table 1). 
The size of the egg chamber could be an 
indicator of nest success. Hummingbird hatch¬ 
lings grow inside their nests and the egg chamber 
increases in size. The egg chamber in the fourth 
and newest nest was wider than the other three 
(Fig. 1. Table 1); we assume this was the only 
nest where eggs apparently hatched, because 
when nestlings grow they expand the egg 
chamber. An entire egg shell broken in two pieces 
TABLE I Dimensions (mm) of four individual nests cl 
Scintillant Hummingbirds built one on top of the other. 
Diameter measurements are perpendicular between nests. 
Nest height is the highest measurements between the 
outside nest bottom and cup border. Nest numbers represent 
the construction order from the oldest (1) to newest (4). 
N«l 
Diameter 
Eag chamber deplh 
Nest height 
1 
19.2 X 22.5 
17.8 
43.2 
2 
20.0 X 22.7 
21.1 
35.8 
3 
19.2 X 22.1 
14.5 
26.0 
4 
21.6 X 24.5 
24.0 
37.9 
