. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SENSITIVITY OF ECHOLOCATION 13 of low amplitude or was complicated by noise, so that there was a danger that some of the pulses might be overlooked in studying the record. Other flights were ex- cluded because the pulse repetition rate varied widely during the 3 to 4 meters of straight flight from point A to the vicinity of the wires or did not return to approxi- mately the same level after the bat passed through the wires. Nor were any flights used unless we were confident that the photographs established the bat's position
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SENSITIVITY OF ECHOLOCATION 13 of low amplitude or was complicated by noise, so that there was a danger that some of the pulses might be overlooked in studying the record. Other flights were ex- cluded because the pulse repetition rate varied widely during the 3 to 4 meters of straight flight from point A to the vicinity of the wires or did not return to approxi- mately the same level after the bat passed through the wires. Nor were any flights used unless we were confident that the photographs established the bat's position with an accuracy of ± 10-15 cm. over at least the major part of its flight through the wires. The time required for sound to travel from bat to microphone was only 10 1) Q- to TJ c O u 0> at. 32IQI Distance from wires (meters) FIGURE 3. Intervals between pulses emitted by a bat flying through a row of wires. about second at the very most, and it decreased gradually as the animal flew towards the wires. Hence the acoustic delay had no appreciable effect on the meas- urement of the interval between pulses. RESULTS More than 500 flights through the wires showed the characteristic increase in pulse repetition rate with only two or three exceptions, all of which occurred with the wire. For the 146 flights selected for analysis the bat's position was determined at the time each pulse was emitted, and the pattern of sound emission in typical flights is shown graphically in Figures 2-6, where each point represents a single pulse. Since the repetition rate varies rapidly it is more appropriate to consider the data in terms of the time interval between pulses. Therefore the or-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biologi
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
