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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 1. March 2012 
by a> the lek. Parameters used in preparation of the sonogram: Win*. 
type-Hamming. n - 324 samples: Time gnd-Overlap 89.8%; Frequency grid-DFT, n = 2,048 samples. 
The aerial display of Plovercrests, in which a 
displaying bird hovers in front and slightly above 
a perched bird, is similar to the shuttle displays of 
North American hummingbirds (e.g.. Anna’s 
Hummingbird. Calypte anna ; Stiles 1982). The 
aerial display of Plovercrests appears to be 
similar to those of lekking hummingbirds in the 
subfamilies Trochilinae (e.g.. Swallow-tailed 
Hummingbirds, Pizo and Silva 2001) and 
Phaethornithinac (e.g.. Long-tailed Hermit 
Stiles and Wolf 1979). as well as those of son 
non-lekking species (e.g., Violet-capped Woo. 
nymph [Thaiurania glaucopis |; M. A. Pizo. per 
obs.). This suggests the aerial display describe 
is deeply rooted in hummingbird phylogeny, ar 
not restricted to lekking activities. Interspecif 
differences in these displays do exist. Hermit 
for instance, often display their gape and thro 
patterns (Stiles and Wolf 1979), which apparent 
does not happen in Plovercrests. However, i 
properly evaluate these aerial displays and compiu 
jose of different species, recording the display 
with video cameras for more detailed analysis w 
be necessary. ■ 
I found no relationship between lek attendance 
by male Plovercrests and singing rate in conuast to 
White-bellied Emeralds (Atwood et al. 1991) 
These authors interpreted singing rates as reflecting 
dominance hierarchies among lekking males that 
might affect mating success. They noted, however, 
the relationship between lek attendance and singing 
rate was detected when the three leks studied were 
pooled for analysis, but became less clear when 
each lek was analyzed separately. Thus, variation 
existed among leks of a single species, and 
certainly exists in an interspecific comparison. 
No relationship between lek attendance and singing 
rate was detected for Plovercrests. but singing rates 
diltered among males. Relating differences to 
possible variation in mating success represents a 
challenge lor researchers because copulations are 
seldom witnessed even for the best studied lekking 
hummingbirds (Stiles and Wolf 1979). A better 
understanding of the relationship between lek 
behavior and mating success will require a 
combination of field effort to locate hummingbird 
nests near leks, and laboratory analysis to ascertain 
the paternity of nestlings. 
