Full Description

"Red drum, Sciaenops ocellata, in particular produce"drumming"sounds (Fish and Mowbray, 1970)."

"Drumming, presumably by males, began around dusk (1900 h). A typical drumming call (Fig. 1) is made up of a burst of pulses (discrete sounds). Pulses contained sound energy up to 2.5 kHz with dominant energy in the 240 Hz-l kHz range. Pulses were of a 70-100 msec duration and calls were irregular in pulse repetition rate (pulses/sec). The first 2 interpulse intervals were greater than others in a typical call."

"Fish were disturbed by noises outside the tank around 1940 h and sound production stopped for a short period. Generally, female(s) swam lethargically near the bottom of the tank and drumming calls were detected as male(s) swam near female(s). If an attended female began swimming actively, the attending male(s) began nudging this individual near her urogenital opening. This activity attracted other males to join in nudging her. No sounds were heard when males were actively nudging females. Courtship seemed to intensify through the evening as evidenced by an increase in drumming and nudging. Mean burst rates (calls/min) and their standard deviations for the hours 1900-2000 h, 2000-2100 h and 2100-2200 h were 2.25 (3.21), 7.15 (3.21) and 16.35 (8.10) respectively. Rates increased significantly as the evening progressed (F = 88.8; d.f. = 2,177; P <0.05). The mean number of pulses/call increased significantly (F = 85.2; d.f. = 2,1524; P < 0.05) for each hour and were 4.37 (1.31), 6.41 (2.26) and 7.81 (3.45). Increased nudging accounted for the decreased number of calls produced during the period from 2020-2050 h and 2100-2110 h (Fig. 2). Nudging and drumming were maximum be- tween 2130 and 2140 h."

"This spawning act took about 30 sec to complete and no sounds were detected during this period."

"Sound production resumed but decreased after spawning."As red drum courtship intensified, calls, pulses/call and pulse repetition rate in- creased. The interpulse interval within a red drum call decreased as the pulse repetition rate increased."

"Drumming and nudging intensified prior to spawning and appeared to be major stimuli for the spawning act of red drum."

Observation Environment Quotes

"Drumming sounds (Fish and Mowbray, 1970). Drumming sounds were heard on several nights of the week 25-30 Aug. 1975 emanating from a large fiberglass tank (29,920 1) containing 3 male and 3 female red drum."

Behaviour Description Quotes

"Courtship seemed to intensify through the evening as evidenced by an increase in drumming and nudging.' 'Drumming and nudging intensified prior to spawning and appeared to be major stimuli for the spawning act of red drum."

Sound Name Quotes

"Red drum, Sciaenops ocellata, in particular produce 'drumming' sounds (Fish and Mowbray, 1970)."

"Drumming, presumably by males, began around dusk (1900 h). A typical drumming call (Fig. 1) is made up of a burst of pulses (discrete sounds). Pulses contained sound energy up to 2.5 kHz with dominant energy in the 240 Hz-l kHz range. Pulses were of a 70-100 msec duration and calls were irregular in pulse repetition rate (pulses/sec). The first 2 interpulse intervals were greater than others in a typical call."