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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 123. No. 2. June 2011 
FIG. 3. Kinematics of display dive of the Volcano Hummingbird. (A): sketch of the dive with stages 1-3 labeled. 
r* f ° ll0Wed . lhe same Rectory as the first dive. (B) and (C): composite images of diving birds fromhigh- 
VT 8 ! 5 o CCUrred 0 02 SCC apar1 ‘ B,rd P ,acemem is approximate in both images, because the 
glided* nT,t T , , (B): eady in ' he dive in which ,he bird tapped its wings as it entered the frame (1.).then 
mulfiple t m es e (- SPre ) ^ -> JUS ‘ “ * the frame ' (C,: the bo,lom of lhe div ^ i" which the male spreads his tail 
re-ascend to the same starting position, and follow 
the same trajectory as the first dive, except for the 
variable ending (Fig. 3A). As a result, in consec¬ 
utive dives the male passed over the recipient 
from the same direction. The direction of the 
dives did not seem to be specifically oriented 
towards the sun or another environmental feature 
that we could identify. 
We obtained high-speed videos of parts of 15 
dives, from seven different males. No single video 
showed the entire kinematic sequence of the dive 
We identified stereotypical stages that appeared to 
e present m all of the dives by comparing the 
different videos. Each video was unique, thus 
samp e sizes for each kinematic stage vary. Males 
descended in stage I (Fig. 3B) on flapping wings 
cd-H a 8 V ! deOS) ‘ They then ceased tapping and 
glided with tail shut (stage 2) for 0.17 ± 0.07 sec 
(n - 4 videos), before repeatedly spreading and 
Fig 3ri'^ e h ,iUl ? h,le com * nu ing to glide (stage 3; 
rig. JL). The tail was spread for 42 ± 9 msec (n = 
more P 7h adS) and ‘ Fr ° m SCVCn videos that showed 
more han one spread, the tail-spread frequency 
<*e -ate at wh'd, the tail was spread and shut) was 
soundm |1 f Wh ’ Ch WaS 0Ot different the 
sound pulse frequency (f-test, P = 0.31). 
Male Volcano Hummingbirds during the dive 
had a wing-beat frequency of 58 ± 1.1 Hz (fl -5 
high speed videos from 2 males). A caged male 
had a wing-beat frequency of 66.7 Hz. while a 
male hovering in the wild had a wing-bo* 1 
frequency of 46.9 Hz; thus, the dive wing-beat 
frequency is within the range observed for 
hovering birds. Two caged females had ahovenng 
wing-beat frequency of 42.7 ± 0.52 Hz. The 
wings did not make an audible wing trill during 
flight, and we did not observe any displays similar 
to the shuttle display of other Selasphorus. 
We observed one or two male 5. f flamnutla 
perform about four dives on 21 October 2009. on 
the summit of Volcdn Irazu, of which we obtained 
a sound recording from one individual. We did 
not detect dramatic differences in the dive 
trajectory trom the kinematics described for S.J- 
torridus (Fig. 2), nor did we detect notable 
differences in the dive sound. 
Scintillant Hummingbird 
Breeding and Territorial Behavior.—We heard 
the wing trill of Scintillant Hummingbirds near 
food plants at Cuerici (2,600 m asl), and one male 
was collected at this location. We did not make 
