Nightly Behavior
We tracked 13 males (all of which sang) and one female that did not
sing, but produced contact calls
(Vaughan 1976, Smarsh
and Smotherman 2015a). We tracked individuals for 4–5 nights each
except for one male who we tracked for 3 nights due to mortality from a
puff adder (Bitis arientans ) (Table 1). We had fewer detections
for another bat due to tag failure (Bat 13, Table 1). On average, we
recorded 46 GPS points (perches) per individual (range 27–77, Table 1).
All 14 individuals returned to the same area nightly during the tracking
period and repeatedly visited these same perches. The mean number of
sampled points we used for KDE analysis was 493 (range 111–673, Table
1). Based on our KDE minimum point criteria (n = 30), we calculated MCPs
and KDEs for all individuals for all range types except one (Table 1).
Site fidelity extended beyond the tracking period, and we recaptured
nine individuals within two months after the radio transmitters ceased
functioning and fell off. The perch trees that bats visited includedA. greggii , A. tortilis , A. mellifera ,Boscia spp., Sclerocarya spp., Terminalia spp.,Balanite aegypica, Ehretia spp., Albizia spp., andEuphorbia tirucalli. One bat used the sides of buildings.
Except for one male who largely stopped singing during our sampling
period (not included in Tables 2 and 3), individuals foraged during
early evening hours, performing short sallies from trees and audibly
chewing, and occasionally singing bouts of songs from perches. The
amount of singing increased hourly throughout the night
(F 5,55 = 10.59, p < 0.01,
η2 = 0.17; Fig. 2, Table 2). Singers sang more in the
later period of the night than the earlier period of the night
(t 11 = -4.29, p < 0.01, d =
1.24; Table 3). The average amount of nightly singing varied across
individuals, between 16.7 min ± 13.46 and 277.73 min ± 26.48 per night
(F11,14.6 = 53.9, p < 0.001,
ω2 = 0.91, Table 3). The total number of perches used
during the tracking period was greater than the number of singing
perches (t 11 = 2.20, p < 0.01, d= 1.48; Fig. 2, Table 3). We tracked the most prolific singers during
the middle of the dry season (June–July, Table 3). More prolific
singers used more singing perches (r = 0.74, p < 0.01,
Fig. 2), but not more perches overall (r = 0.24; p = 0.43). More
prolific singers had smaller testes (r = -0.86, p < 0.05) and
used a smaller number of perches (r = -0.92, p < 0.01).
Forearm length did not correlate with average nightly singing and perch
use (rFA-MeanS = -0.25, p = 0.44;:rFA-SPerches = -0.51, p = 0.09).
Individuals varied in their singing behavior, either spending the
majority of their singing time at particular perches (e.g. Bat 11 spent
70% of his singing time at one perch; Table 3, Figs. 2, 3), or using
perches more evenly for singing (e.g. Bat 6 spent 19% of his singing
time maximum at one perch; Table 2, Fig. 3). We found no relationship
between average nightly singing and the maximum percent of time spent
singing at a single perch (ρ = -0.09, p = 0.78).