Electronic supplementary material captions:
S1: Extended methods details.
S2: Terminal frequency differences between jammed and jamming bats. Relative terminal
frequency between jamming and jammed bats when jammed by conspecifics for call durations
of 2-4ms.
S3: Jamming treatments table. The different treatments and the jamming sequences used in
them. Bats landed between 10-23 times at each session.
S4: Flight-room spatial coverage. Jamming did not cause an altering of spatial coverage of
the room. Black square represents flight room 2D projection (view from above). Brighter areas
are areas used more frequently by the bat. The angle of flight towards target during search was
also unaffected by jamming (two right-most panels). Data shown are for bat 1 and 2 (top and
bottom rows).
S5: Effect of jamming on performance – individual variation. (A) Landing rate in empty
room (number of landings per second flown) without jamming was not reduced by various
jamming conditions and severities. (B) Obstacle avoidance performance in cluttered room was
unchanged under jamming for one bat and decreased (by 10% on average) in three bats
(binomial test: bat 1 p=0.59, bats 2 p=0.003, bat 3 p=0.0026, bat 4 p<0.001). Bat 3 preformed
only one session in jammed cluttered conditions, hence the lack of error bars.
S6: Effect of jamming on echolocation during target-approach. Individual bat data of call
intensity (top four panels) and call duration (bottom four panels) during approach to target.
Both parameters decreased during approach to landing (time ‘0’), but calls stayed louder and
longer when bats were jammed when compared to no jamming (blue line).
S7: Effect of jamming on echolocation during search phase. Individual bat data of call
intensity vs. duration (90% contour of the 2D histogram) in uncluttered (A-D) and cluttered (EH) room during search phase flight. Bats used longer, more intense calls when jammed.
S8: Frequency shifts increase spectral overlap. When jammed by their own calls artificially
shifted 2.5kHz upwards, two additional bats (A-B) shifted their calls upwards in frequency, thus
increasing spectral overlap between the jamming signal (black line) and their own calls (gray
dotted line).
S9: Individual recognition based upon spectral parameters. Confusion matrices of correct
and incorrect identification of each bat in the different jamming conditions. Number of calls
used in parenthesis. Tables 1-5 are based upon two spectral parameters – peak and terminal
frequencies. Table 6 is based upon seven parameters – the previous two plus the following five:
median frequency (frequency of the median intensity of the pulse over all its intensity values),
peak intensity (highest intensity value measured in the call) of 1st harmonic, peak intensity of
2nd harmonic, 1st-to-2nd harmonic intensity ratio, and pulse duration. All parameters were
derived from the calls spectrograms (FFT length 512, 99% overlap). Values are for all jamming
conditions combined.
S10: intensity differences between calls and echoes. Call and target echo intensities of an
artificial P. kuhlii search call as recorded from 1 meter by a calibrated microphone (GRAS,
40DP). (A) 3ms call recorded with the speaker facing the microphone head-on. In good
proximity, there was always a speaker directly in front of the bat. Peak intensity is at 37.3kHz.
(B) The echo of the same call returning from the landing target, recorded 1 meter away from
the target. Intensity was reduced by 10.9db. This is the maximal echo possible from this target
at this distance, and if the bat would fly at any different angle or height the resulting echo will
be weaker.
S11: Durations distribution in large space. Bats flying in a larger (5x4x3 m3), uncluttered
flight room produced search-phase echolocation calls with an average duration of 3.2±0.01ms
(mean±se, blue bars). In the 100% duty-cycle jamming bats produced calls of similar durations
(3.5±0.01ms, red-bars).