Clark et al. • SCINTILLANT AND VOLCANO HUMMINGBIRD COURTSHIP 
227 
Thus, the presence of food on a territory is not 
evidence that it is a feeding territory. Some of the 
densest food resources (blooming Fuchsia, Cen~ 
tropogon) that occurred in closed canopy ap¬ 
peared to be undefended, whereas we only 
observed territories in open areas. In the related 
Anna's and Calliope hummingbirds, males will 
hold breeding territories in the absence of food 
(Tamm 1985. Armstrong 1987, Powers 1987. 
Tamm et al. 1989), and even those holding a 
territory with food resources tend to have less 
food available than nearby undefended locations 
( Armstrong 1987). We suggest that breeding male 
Volcano Hummingbirds are not guarding territo¬ 
ries for the floral resources that they contain. 
Males could also hold territories to guard 
resources other than flowers, such as insects (for 
which females have high demand when breeding) 
or nesting sites. Females did not seem to nest on 
male territories. It is possible they visited 
territories of males to obtain resources such as 
nectar or insects (Temeles and Kress 2010), but 
we made no direct observations that would 
support this idea. Our interpretation of the 
Volcano Hummingbird’s territoriality is that 
males need open areas to perform the display 
dive, and the primary function of the territory is 
courtship, making the mating system most similar 
to an ‘exploded’ lek. 
The function(s) of the territories of male 
Scintillant Hummingbirds were less clear. The 
six males we found all had ample food resources 
on their territories, and defended their territories 
from Volcano Hummingbirds (nectar competitors) 
and male Scintillant alike, similar to the interspe¬ 
cific territoriality of breeding male Anna’s and 
Allen’s hummingbirds (Pitelka 1951). Moreover, 
a female was seen extensively feeding on one of 
these territories, although she did not appear to 
reside there. These observations suggest that 
resources have a role in the territory ownership 
of these males, perhaps more so than for Volcano 
Hummingbirds. 
However, as for the Volcano Hummingbird, all 
six of these territories were held in open areas. 
Dense patches of flowers in areas with greater forest 
canopy cover had many male and female Scintillant 
Hummingbirds visiting them, but we did not detect 
any male territories in these closed areas. It is 
possible the males visiting these flowers were not 
holding territories but, as males of related species 
are known to forage away from their breeding 
territories (Armstrong 1987; Powers 1987; CJC, 
pers. obs.), we suspect the males we observed at 
these flowers held a territory elsewhere, and were 
commuting from their territories to feed. If true, we 
hypothesize that, as in the Volcano Hummingbird, 
habitat structure is more important than food 
availability for territory location. This hypothesis 
could be tested by covering or removing the flowers 
on male territories (e.g., Armstrong 1987) to 
examine if territorial behavior is maintained in the 
absence of floral resources. The potential difference 
in the importance of food on breeding territoriality 
between the Scintillant and Volcano hummingbirds 
would make for an interesting comparative study. 
ACKNOWLEDGMENTS 
Wc thank Jennifer Marks and Anand Varma for field 
assistance. We are grateful to Alberto Munoz and Carlos 
Solano at Estacion Bioldgica Cuerici, Marino Chacdn and 
the Savegre Hotel, and David Hille and the QERC for 
lodging and permission to perform field-work. We 
appreciate the comments that two reviewers provided. This 
research was performed under M1NAET permit # 04348 to 
CJC. Funding was provided by NSF # IOS-0920353. 
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