Full Description

"The boatwhistle sound produced by male toadfish during the reproductive season attracts females to the nest site. Boatwhistles consist of a series of rapidly produced, amplitude modulated 'pulses' of sound that are generated by specific muscles of the gas bladder. Previous studies have shown that boatwhistle characteristics vary with temperature and geographic location."

"Pulse repetition rates varied from a low of 125 pulses/sec at 16 °C to a high of 219 pulses/sec at 21 °C. Careful examination of recordings from different sites indicated that individuals vary in the durations of their boatwhistles as well as in the pulse repetition rates during the very consistently produced second segment of the call. In particular, pulse repetition rate (PRR) varied significantly (p < 0.001) among most individuals recorded at the same temperatures."

"Male toadfish defend a nest site to which they attract females, at least initially, by producing a boatwhistle sound (Tavolga 1960, Fish 1954)."

"In the Chesapeake Bay, males are known to continue producing boatwhistles over several weeks until the young are free-swimming (Hildebrand and Schroeder 1972) and may produce boatwhistles at a successful nest site for more than a month (Gray and Winn 1961)."

"Boatwhistle production ends with the breeding season (Fish 1954, Gray and Winn 1961); however, both males and females continue to produce a grunt in agonistic contexts (Fish 1954; personal observations)."

"The boatwhistle is often described as a tonal sound, while the grunt is described as a harsh, pulsed sound (e.g. Gray and Winn 1961, Zelick et al. 1999)."

"Each contraction of the sonic muscle produces a compression and rarefaction event with regard to the gas bladder (Fine et al. 2001), which is represented by a sinusoidal frequency component on a spectrogram."

"The boatwhistle and the grunt vary primarily in duration and in the rate and regularity of the pulsing, which affects the quality of the sound to the human ear. There is good evidence that boatwhistle characteristics vary with temperature. Fine (1978) found that field recordings of boatwhistles recorded at a single site over six days with tidal temperature fluctuations showed variations in the frequency content consistent with temperature effects."

"st vary seasonally in our study area as water temperatures rise. In addition, considerable variation was present in the boatwhistle data collected at each temperature by Fine (see Figures 7 and 8 in Fine 1978), suggesting to us that boatwhistles may vary due to individual differences as well as temperature effects."

"We discovered that consecutive boatwhistles from a single individual were very similar, and multiple individuals could be distinguished from each other when multiple males were calling. Therefore, we have also considered the potential for individual variation in the boatwhistles of male toadfish."

"Although one study suggested that average toadfish calling rates are not different during daylight versus night (Fine et al. 1977), Winn (1972) found that neither males nor females responded to boatwhistles between 0900 and 1730 hr."

"Calling rates of more than 10 boatwhistles/min were reported by Winn (1967) and similar calling rates were common in Waquoit Bay."

"Toadfish males produce their boatwhistles while stationary at a nest site (Gray and Winn 1961)."

"In reviewing all the spectrograms and power spectra for boatwhistles, we noted that either the first or the second harmonic could have the greatest acoustical energy."

"Spectrogram illustrating harmonic bands. The pulse repetition rate is represented by the consistent difference between the frequency bands (Watkins 1967). (B) Waveform ofthe same sound illustrating the two components of the boatwhistle. Segment 1 has irregular pulsing; segment 2 has regular pulse repetition rates. Amplitude appears to vary in part due to background noise, seen prior to and after the boatwhistle."

"The boatwhistle consists of two components (Figure 2): a brief initial grunt during which pulsing is irregular (segment 1) and a longer period of very regular pulsing (segment 2)."

"The pulsing pattern in segment 2 was very consistent for each individual, as reflected by the low standard deviation for pulse repetition rate (PRR, Table 1). Interpulse intervals were also very consistent, with standard deviations of 0.1 msec or less for all fish independent of temperature."

"During the sound analyses, we noted that the consecutive calls from recordings of a single individual had nearly identical waveforms (example shown in Figure 3)."

"Therefore, mean boatwhistle duration can vary significantly among individuals at the same temperature but may not be significantly different in all individuals. Duration alone is unlikely to be useful for individual identification."

"Figure 4 illustrates differences in the relative acoustic energy in the harmonics produced by three different fish (as determined by their distinctive waveforms). This distribution of acoustic energy may be useful for identifying individuals in a breeding area with multiple nest sites."

"Considerable variation was present in a temporal component, the pulse repetition rate, which also determines the harmonics present in the boatwhistle."

"The description provided by Tavolga (1960) for BWs from Opsanus tau off Florida indicated relatively high pulse repetition rates (250 pulses/sec) compared with those we report (Table 1) but higher pulse repetition rates for toadfish off Florida are not inconsistent given the likelihood of warmer temperatures (temperature was not reported in that study). Tavolga (1960) also noted that individuals varied in their 'fundamental frequencies' by +/-20 Hz but more specific data on individual variation were not presented. We conducted a detailed analysis of BWs from various individuals at known temperatures and found variation in pulse repetition rates (= fundamental frequencies of Tavolga) of similar magnitude (Table 1) in the Waquoit Bay population."

"Boatwhistle durations in the Waquoit area population averaged 238-531 msec across all the individuals. This range of values was also found in other populations. In Delaware, BWs averaged 376-475 msec prior to midJuly; in Virginia, BWs averaged 190-348 msec; in South Carolina, BWs averaged 246-506 msec (Fine 1978)."

"Winn (1972) found that boatwhistles or tones (e.g., 200 Hz) 300 to 1,000 msec in duration were stimulatory but boatwhistles or tones less than 150 msec or substantially longer than 1,000 msec did not stimulate calling. The 150 msec duration is comparable to the duration of grunts, which are similar spectrally to boatwhistles and are produced in agonistic contexts by both males and females (Fish 1954, Gray and Winn 1961)."

"Frequency may be most important for species recognition and duration is clearly important for distinguishing an agonistic grunt from a reproductive boatwhistle. Duration may also distinguish individuals when multiple males are calling (see below)."

"Pulse repetition rate is the most consistent temporal parameter within a series of boatwhistles produced by an individual fish (Table 1) and can be significantly different among fish calling at the same time (Tables 2,3)."

"sound production capabilities. Behavioral studies have indicated that toadfish alter their acoustic behavior in response to the behavior of conspecifics. Toadfish can be induced to boatwhistle or increase their calling rate (vocal facilitation) by the calls of another toadfish, playback of boatwhistles (Winn 1967, Fish 1972), or the approach of a female (Fish 1972). In addition, Winn (1967) stated that individuals avoid overlap of their boatwhistles with those of conspecifics and Fish (1972) showed that a toadfish will initiate a boatwhistle within 1.5-2.0 sec of the termination of a stimulus boatwhistle but avoids overlap with the stimulus."'Contrary to their observations, we recorded overlapping boatwhistles when multiple males were calling at the height of the breeding season."

"Therefore, we suggest that there may be an alternative mechanism for an individual to remain distinctive when among multiple calling conspecifics."

"The duration of boatwhistles varied (average: 238.3 to 531.5 msec) independent of temperature (R2 = 0.1343)."

Observation Environment Quotes

"Recordings were made from a small boat at anchor in water 2-3m deep in estuarine waters in and around Waquoit Bay, near Falmouth, Massachusetts, USA (Figure 1)."

Behaviour Description Quotes

"The boatwhistle sound produced by male toadfish during the reproductive season attracts females to the nest site. Boatwhistles consist of a series of rapidly produced, amplitude modulated 'pulses' of sound that are generated by specific muscles of the gas bladder. "

"Boatwhistle production ends with the breeding season (Fish 1954, Gray and Winn 1961); however, both males and females continue to produce a grunt in agonistic contexts (Fish 1954; personal observations)."

Sound Name Quotes

"The boatwhistle sound produced by male toadfish during the reproductive season attracts females to the nest site. Boatwhistles consist of a series of rapidly produced, amplitude modulated 'pulses' of sound that are generated by specific muscles of the gas bladder. "

"Boatwhistle production ends with the breeding season (Fish 1954, Gray and Winn 1961); however, both males and females continue to produce a grunt in agonistic contexts (Fish 1954; personal observations)."

"The boatwhistle is often described as a tonal sound, while the grunt is described as a harsh, pulsed sound (e.g. Gray and Winn 1961, Zelick et al. 1999)."

"In reviewing all the spectrograms and power spectra for boatwhistles, we noted that either the first or the second harmonic could have the greatest acoustical energy."

"The boatwhistle consists of two components (Figure 2): a brief initial grunt during which pulsing is irregular (segment 1) and a longer period of very regular pulsing (segment 2)."