Abstract
The behavior of Atlantic bottlenose dolphins (Tursiops truncatus) in managed care facilities is extensively researched, with numerous publications investigating daily species-specific behaviors and behaviors on/off sessions (Shane et al., 1986; Clegg et al., 2017). Daily behaviors expressed by bottlenose dolphins include social, solitary, high- and low-energy, and aggressive behaviors, among others (Harvey et al., 2017; Heuttner et al., 2021; Walker et al., 2017). However, the nocturnal behavior of these populations is understudied and underrepresented in literature. Much of the literature on the nocturnal behavior of managed care populations focuses on sleeping habits (Lyamin et al., 2008; Sekiguchu & Koshinma, 2003), leaving questions about their nightly social behavior. Therefore, this research aims to further our understanding of the nocturnal social behavior of bottlenose dolphins in managed care settings. The nocturnal behavior of seven resident Atlantic bottlenose dolphins was observed in the fall of 2022 at Dolphins Plus Marine Mammal Responder in Key Largo, FL. To gain a daily representation of social behavior, observations were conducted off session six times in 24 hours (12:00 AM, 4:00 AM, 8:00 AM, 12:00 PM, 4:00 PM, and 8:00 PM), three to five times weekly, lasting 20-minutes each. Our results show that bottlenose dolphins were active over a 24-hour period, but the type of activity varied. During the day, solo, high-speed swimming was most prevalent. At night, synchronous swimming at slower speeds were observed, implying that rest was occurring during these hours. These results are consistent with other published literature and predictions of bottlenose dolphin behavior over a 24-hour period (Clegg et al., 2017; Gnome et al., 2001; Heuttner et al., 2021; Kremers et al., 2014; McBride & Hebb, 1947; Saayman et al., 1973; Sekiguchu & Koshinma, 2003; Shorter at al., 2017; Walker et al., 2017)). Additionally, individual differences among lagoons were observed based on age and sex (Bouveroux & Mallefet, 2010; Connor et al., 2001; Eskelinen at al., 2015; Wells, 2014). These results further our understanding of nocturnal social behavior in managed care populations to aid management practices and help fill a knowledge gap within daily bottlenose dolphin social behavior.