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).