Abstract

Red hind (Epinephelus guttatus) form transient spawning aggregations that follow a lunar cycle (Colin et al. 1987, Shapiro et al. 1993, Sadovy et al. 1994). Passive acoustic monitoring has shown to be a reliable indicator of this temporal pattern in reproductive activity (Appeldoorn et al. 2015, Mann et al. 2010, Rowell et al. 2012). Long-term passive acoustic monitoring and surveys of red hind abundances at Abrir la Sierra (ALS), Puerto Rico have shown that peak aggregations consistently occur 7-10 days after full moon (DAFM). However, acoustic records revealed occasional, extended periods of increased rates of sound production prior to the expected aggregation period. Red hind calls have been previously described as a series of pulses of variable repetition rate with a minimum and maximum frequency of approximately 130Hz and 250Hz respectively (Mann et al. 2010, Rowell et al. 2012). Sounds are associated with courtship, mating or territorial behavior and are mostly produced during the aggregations associated to reproduction (Mann et al. 2010). Recently, Zayas et al. (unpublished manuscript) have characterized red hind sounds into multiple types (“A”, “B”, “A+B”, “Other” and “Chorusing”). We analyzed calling behavior to establish temporal patterns by signal type during the lunar spawning cycle. Once this was established, we applied the same analysis to the extended periods of calling activity and used these patterns to infer behavior.

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