Fig. 1. A sonagram of calls emitted by a Daubenton's bat attacking a target. The vertical arrow indicates the time at which the bat first hits the target. The lower panel shows an enlargement of pulses `a' and `b', representing a pulse emitted far away (±1.5m) and near (±0.1m), respectively, from the target. The consecutive panels show that the pulse repetition rate is increased during the approach, whereas the bandwidth of the first harmonic is decreased during the final stage of target approach. At this stage, energy in higher (>3^rd) harmonics can be visible when the bat is recorded at a close distance (upper panel).

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