. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ECHOLOCATION OF FLYING INSECTS as to avoid walls and ceiling, etc., but we have not yet recognized patterns of be- havior in cruising flight other than an apparent varying regularity. Two such long, cruising sequences, recorded at high amplitude and lacking patterns sug- gesting insect pursuit, have been analyzed. These lasted 770 and 870 msec., respectively. Pulse durations of to msec, occurred, with a mean of msec. Interpulse intervals (the silent period between pulses) vuru-d from 44 to 84 msec, with a mean of
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ECHOLOCATION OF FLYING INSECTS as to avoid walls and ceiling, etc., but we have not yet recognized patterns of be- havior in cruising flight other than an apparent varying regularity. Two such long, cruising sequences, recorded at high amplitude and lacking patterns sug- gesting insect pursuit, have been analyzed. These lasted 770 and 870 msec., respectively. Pulse durations of to msec, occurred, with a mean of msec. Interpulse intervals (the silent period between pulses) vuru-d from 44 to 84 msec, with a mean of 56 msec.; almost all lay between 44 and 65 msec. The repetition rate was about 17-18 pulses per second in both series. Thus, ^arch- ing flight in C. psilotis seems to consist of a sequence of pulses about 4 msec, in duration, spaced about 60 msec, apart. 75 50 C. o o 0) 25 x—. x—x—x pulse duration ®—®— interpulse interval 125 250 375 milliseconds 500 625 FIGURE 2. An example of a fruit fly pursuit by C. psilotis. Pulse duration and interpulse interval are plotted against milliseconds before the end of the pursuit. One msec. — mm. (see text). The arrow indicates the first calculated pulse-echo overlap. Note that in Figures 2 through 5, time reads from right to left (larger numbers represent earlier events). The approach phase begins, by definition, in these analyses, at the point at which we first recognize that the bat is committed to a complete pursuit. In Pteronotus (Novick, 1963b), this point was recognized by the first obvious short- ening of the interpulse interval. Systematic changes in pulse duration also oc- curred, but their initiation point was harder to pinpoint. In C. parnellii (Novick and Vaisnys, 1964), the beginning of the approach phase is signaled by an in- crease in pulse duration while changes in interpulse interval occur gradually and are initially hard to identify. In C. psilotis, the beginning of the approach phase is m
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
