Full Description

"Chorusing sounds from both species were detected at all three Georgia sites and at two of the three North Carolina locations; chorusing duration of both species was greater in Georgia. The onset and duration of chorusing activity for both species was correlated with water temperature."

"In habitats where they occur, the chorusing sounds of black drum and oyster toadfish are two of the major contributors to the acoustic environment in terms of the amplitude, duration, and frequency of their calls (e.g., Locascio and Mann 2011a; Montie et al. 2015)."

"Though both species use sounds in reproductive behavioral contexts, the reproductive ecology of these species is quite different."

"Males from both species produce distinct calls using muscles attached to the swim bladder (Tower 1908) that can be extremely high amplitude: in the case of black drum, sound levels often exceed 160 dB re: 1 _Pa (Locascio and Mann 2011b), and 130 dB re: 1 _Pa for Opsanus tau (Barimo and Fine 1998)."

"We analyzed 12 h of each day from 0:00–6:00 and 18:00–24:00, since black drum typically call in choruses from sunset to sunrise (Mok and Gilmore 1983; Locascio and Mann 2011a) and toadfish chorus throughout the day (Fine et al. 1977)."

"Black drum calls were distinguished from other biological and anthropogenic sounds using the following criteria (following Fish and Mowbray 1970; Mok and Gilmore 1983): (i) fundamental frequency occurred between 70 and 120 Hz; (ii) 0–4 harmonics were visible; (iii) duration ranged from 0.2–0.5 s; and (iv) signal contour sloped downward (i.e. frequency decreased)."

"At this time resolution, black drum or toadfish choruses are visible as a continuous band of signals corresponding to the fundamental frequencies and harmonics of each species’ call (approximately 80 Hz, 160 Hz, and 240 Hz for black drum; approximately 120 Hz and 240 Hz or 230–250 Hz for toadfish) (Fig. 3)."

"Chorusing occurred most frequently between 18:00 and 5:00 (Fig. 5), and exceeded amplitudes of 100 dB at frequencies corresponding to the fundamental frequency and harmonics of the call, at approximately 80 Hz, 160 Hz, and 240 Hz (Figs. 3 and 5)."

"Chorusing produces sound levels >120 dB at the fundamental frequency of the call (~80 Hz) and sound levels >100 dB at the first and second harmonics (~160 Hz and 240 Hz)."

"Since much of the calling behavior of both species is associated with reproductive advertisement displays (e.g., Gray and Winn 1961; Locascio et al. 2012), and both species spawn in shallower coastal waters (Gudger 1910; Gray and Winn 1961; Mok and Gilmore 1983), it is possible that the Georgia locations provide more suitable habitats for reproductive or social behaviors."

"This nearly simultaneous onset of chorusing activity over a 25 km distance suggests an environmental cue, such as water temperature, triggers the initiation of reproductive behavior (e.g., Mann and Grothues 2009), though it is possible that there could be a spatially extended chorus that stimulates calling (D’Spain and Batchelor 2006)."

"Black drum were predominantly present from the autumn through spring (November – April 2013), while toadfish were predominantly present in the early spring and summer (March – April 2013 and June – August 2012) (Fig. 4)."

Observation Environment Quotes

"Acoustic data were collected using marine autonomous recording units (MARU) (Calupca et al. 2000) that were deployed at two sites centered on U.S. Bureau of Ocean Energy Management wind energy planning areas off the coasts of North Carolina and Georgia (Fig. 1)."

Behaviour Description Quotes

"Though both species use sounds in reproductive behavioral contexts, the reproductive ecology of these species is quite different. "

"Since much of the calling behavior of both species is associated with reproductive advertisement displays (e.g., Gray and Winn 1961; Locascio et al. 2012), and both species spawn in shallower coastal waters (Gudger 1910; Gray and Winn 1961; Mok and Gilmore 1983), it is possible that the Georgia locations provide more suitable habitats for reproductive or social behaviors."

Sound Name Quotes

"Chorusing sounds from both species were detected at all three Georgia sites and at two of the three North Carolina locations; chorusing duration of both species was greater in Georgia. The onset and duration of chorusing activity for both species was correlated with water temperature. ' 'Black drum calls were distinguished from other biological and anthropogenic sounds using the following criteria (following Fish and Mowbray 1970; Mok and Gilmore 1983): (i) fundamental frequency occurred between 70 and 120 Hz; (ii) 0–4 harmonics were visible; (iii) duration ranged from 0.2–0.5 s; and (iv) signal contour sloped downward (i.e. frequency decreased)."