All dolphin photography taken under MMPA Permit #21938-03.
May not be used for commercial purposes.
 Figure from Hamilton et al. 2022. By Mira Johnson, Field Assistant Like many coasts along Florida, the Nature Coast is home to many resident bottlenose dolphins. But what makes this area an exceptionally remarkable field site for the Cedar Key Dolphin Project is the unique behavior called Driver-Barrier foraging, which is known to only take place there. Driver-Barrier foraging behavior is a role-specialized foraging tactic performed by bottlenose dolphins to catch mullet. The behavior fittingly received the name, Driver-Barrier, for its involvement of one individual serving the role of Driver and one or more as Barrier(s) to forage. The interaction begins with a Driver rapidly circling a school of mullet in a clockwise direction. As the driver herds the mullet, Barrier dolphins position themselves by the outlet of the closing circle to meet the Driver. Once trapped in the circle, in an attempt to flee, the mullet leap out of the water where the dolphins await the fish with their heads above the surface (see diagram on the right). What a crazy way to catch fish! But just how do these dolphins coordinate such a complex interaction? This is one of the many questions we are hoping to answer by studying Driver-Barrier using techniques such as video, photography, acoustics, and GPS. Video recordings (i.e., hand held camera, drone, and Insta 360) and photographs help us identify individual dolphins as drivers or barriers and determine how many fish they catch. To investigate the use of vocalizations during Driver-Barrier events, we also submerge hydrophones (underwater microphones) in the water. This device allows us to record whistles that we otherwise cannot hear from the surface! The GPS lets us pinpoint where the Driver-Barrier behavior happens, while the drone allows us to obtain an aerial view of the behavior. Observing from this unique perspective has been very helpful in understanding how the Driver and Barrier work together to herd fish. To see Driver-Barrier in action, watch our video at YouTube! From our research, we have learned a lot about this fascinating role-specialized behavior. One of the things we have learned from using acoustics is that echolocation is likely the cue used to coordinate Driver-Barrier behavior. During a Driver-Barrier event, there is a notable lack of whistles which suggests that dolphins must be relying on some other cue than vocalizations to coordinate movement. It is unlikely that the primary cue is visual, as the low water clarity in which Driver-Barrier takes place makes for poor visibility. Therefore, it is thought that dolphins are listening to and reacting to each other's clicks.
Interesting! So echolocation does seem to help coordinate this behavior. But then the question becomes, who is responding to who? Research suggests that Barriers are likely listening to the Driver’s echolocation to coordinate movement and timing. However, whether the Barriers are using the driver’s echolocation directly or indirectly (i.e., eavesdropping) is still unclear. As you can see, although there is a lot that we have learned from studying Driver-Barrier, there is still much to be uncovered. As we look forward to this field season, we hope to continue to gather data on Driver-Barrier that will hopefully help us answer some of our next questions, like 1) does every Driver and Barrier work a foraging event in the same way or are there differences in technique? 2) How do dolphins learn this behavior? Is it from their cohorts or from their mothers? All good research leads to more and more questions to be answered! To learn more about Driver-Barrier, please feel free to read some of the publications by Dr. Gazda and colleagues referenced below. You can find PDFs in our publications section on our website. Hamilton, R. A., S. K. Gazda, S. L. King, and R. C. Connor. 2022. Bottlenose dolphin communication during a role-specialized group foraging task. Behavioural Processes. 104691. https://doi.org/10.1016/j.beproc.2022.104691 Gazda, S.K. 2016. Driver-barrier feeding behavior in Bottlenose dolphins (Tursiops truncatus): new insights from a longitudinal study. Marine Mammal Science. doi: 10.1111/mms.12314 (PDF) Gazda, S.K., R.C. Connor, R.K. Edgar, and F. Cox. 2005. A division of labour with role specialization in group-hunting bottlenose dolphins (Tursiops truncatus) off Cedar Key, Florida. Proceedings of the Royal Society of London Series B-Biological Sciences. 272: 135–140.
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 By Jolinde Vlaeyen, Lab Manager
Have you ever wondered if dolphins have conversations like we do? This is exactly what we are aiming to answer with this year’s field season! We will dive into the environment of the Cedar Keys’ bottlenose dolphin population to investigate how these intelligent mammals take turns during their underwater "conversations”. Why dolphins? I am currently a PhD student with the Comparative BioCognition lab in Osnabrück, Germany, where we all investigate turn-taking abilities in different species, with the goal to show that humans are not so unique in this aspect of communication. Specifically, I am doing this, while comparing wild bonobos, who I followed for 10 months in the middle of the jungle in the Democratic Republic of Congo, and wild dolphins, here around the Cedar Keys. Most of my research has been on primates in the past, but when I came to the CKDP as a field assistant for the first time in 2018, I saw so many similarities between dolphins and primates! Except for the different environment they live in, and a 95 million-year evolutionary gap, dolphins exhibit remarkable similarities in behavior and cognitive abilities. For example, both dolphins and bonobos live in fission-fusion societies, meaning they meet different individuals on a daily basis. The Human-Dolphin Connection Turn-taking is a cornerstone of human communication. When we talk, we follow structured rules about who speaks when, ensuring our conversations flow smoothly. This seamless exchange happens in a blink of an eye, showcasing our cognitive skills. But is this ability unique to humans? Recent studies suggest otherwise, pointing to similar behaviors in birds and social mammals. Now, for the first time, we will be investigating what turn-taking looks like in bottlenose dolphins, a species known for its complex vocalizations and social behaviors. Dolphins use distinct whistles, unique to each individual, to communicate, and often respond to each other within a second—much like humans. They also adjust their vocalizations based on their social context, suggesting advanced communication skills. What do we want to learn? We want to answer the question of whether bottlenose dolphins exhibit elements of human conversational turn-taking during their social interactions. For example, how quickly do dolphins respond, and will this be similar when using different methods(e.g. vocal vs gestures)? Will dolphins respond to a specific signal with the exact same response all the time, and if they do not receive an appropriate response the first time, will they elaborate and/or repeat a signal? Do dolphins use cues to make the recipient understand that it's their turn to respond? Therefore, we will look at dolphin communication in different contexts, such as mother-calf interactions, or group foraging and traveling. Specifically, we will look into four elements of turn-taking that are based on what we see in humans: 1. WHO takes the next turn; 2. HOW turns are organized; 3. WHEN responses occur; and 4. WHAT the next turn should be. How will we do this? To explore dolphin turn-taking, we will use a variety of tools:
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