Past dolphin research at DRC
	MARINE MAMMAL STRANDINGS		METACOGNITION IN DOLPHINS
	MATCH TO SAMPLE		DOLPHIN STRUCTURED SWIMS
	LANGUAGE RESEARCH		SIGNATURE WHISTLES
	DOLPHINS REACTIONS TO OIL FILMS		IMMUNOLOGY
	DOLPHIN-CHILD THERAPY AT DRC

For many years, DRC was a member of the Southeast Stranding Network. The DRC Marine Mammal Rescue Team played an important role in strandings and rehabilitation efforts. Unfortunately, the causes of strandings are often unknown. Illness is one possibility. For the safety and well being of the dolphins that live at our facility, DRC prudently pulled back from on-site assistance. While we continue to provide a great deal of resources, support, and knowledge to other teams assisting in dolphin and whale strandings, we must safeguard our own pod.

DRC plays a major role in manatee rescue in the Florida Keys. To learn more about DRC’s Manatee Rescue Team and how you can help click here.

Our involvement with strandings contributed a great deal of information to the scientific community. Marine mammal strandings provide invaluable opportunities to study species which may otherwise provide only fleeting glimpses at sea. As a member of the Southeast Stranding Network, the DRC Marine Mammal Rescue Team not only provided medical attention for living stranded animals, but collected massive amounts of data.

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Language work with dolphins began at the Institute for Delphinid Research (now Dolphin Research Center) in 1978. The objective was to investigate the possibility of training language-like behaviors to dolphins. Language was defined as consisting of two levels: the naming of objects, and syntax. Syntax refers to the importance of word order when putting nouns with verbs.

An acoustic language using whistles was utlilized. The dolphins were taught that different whistles represented different objects or actions. The whistle language was digitized by a computer and could be produced through an underwater loudspeaker. A juvenile male dolphin named Natua learned four nouns and three verbs. Once Natua understood the words (whistles) for the objects and actions, he was presented with a two-word sentence. When presented with his first combination, the whistles for "towel"/"over", he understood immediately and jumped over the towel in the water. Natua went on to learn a number of two-word combinations such as rock retrieve, towel under, etc. Lack of funding ended this project, but the following year, a television reporter came to cover the story. Natua was given all the different combinations he had learned a year before and responded correctly to almost all of the sequences, indicative of long term memory in dolphins.

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The objective of this study was to determine if bottlenose dolphins could detect an oil slick on the surface of the water. In the initial experiment, the dolphins viewed a transparent cylinder and learned to press a paddle when they detected something in the cylinder besides water. It was demonstrated that dolphins could discriminate between oil and the uncontaminated surface of the water.

This project also showed that dolphins would avoid an oil slick, as they would hesitate to swim beneath one when detected. Their few contacts with the oil (either accidental or as part of an investigative process) resulted in an overt startle response, which set a pattern for subsequent avoidance.

Overall, the dolphins avoided oil both during the day and at night, although the response broke down when the threshold of their ability to detect the oil was reached. Visual cues were instrumental in the dolphins' detection of the oil, and tactile sense played the most important role in their response to the oil. Memory of its location influenced their behavior, even after the oil was removed.

References:
Geraci, J.R., St. Aubin, D.J., and Reisman, R.J. 1983. Bottlenose dolphins, Tursiops truncatus, can detect oil. Canadian Journal of Fisheries and Aquatic Sciences, 40(9): 1516-1522.

Smith, T.G., Geraci, J.R., and St. Aubin, D.J. 1983. Reaction of Bottlenose dolphins, Tursiops truncatus, to a controlled oil spill. Canadian Journal of Fisheries and Aquatic Sciences, 40(9):1522-1525.

St. Aubin, D.J., Geraci, J.R., Smith, T.G., and Friesen, T.G. 1985. How do Bottlenose dolphins, Tursiops truncatus, react to oil films under different light conditions? Canadian Journal of Fisheries and Aquatic Sciences, 42(3):430-436.

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Learning In-Water With Dolphins vs. Learning On Land Without Dolphins: 1988

The dolphins at DRC participated in this project to help increase cognition for children with mental disabilities. Six children were taught new vocabulary words through interaction with dolphins.

Results indicated the children learned two to ten times faster and with greater retention when working with the dolphins. Benefits included increased evidence of the efficacy of using non-human species to increase attention, elicit speech, and increase memory for people with disabilities. One question remained: was it the dolphins’ presence that made the difference, or simply being in-water?

Reference:
Nathanson, D. E. 1989. Using Atlantic bottlenose dolphins to increase cognition of mentally retarded children . In P. H. Lovibond & P. H. Wilson (Eds.), Clinical and abnormal psychology (pp. 233-242). Amsterdam: North-Holland.

Learning In-Water with Dolphins vs. Learning In-Water without Dolphins: 1991

After four years of successful ongoing dolphin-assisted therapy at the Dolphin Research Center, a 1991 study explored the role that water may play in the therapy. This research compared the effectiveness of in-water work without dolphins to in-water work with dolphins on the cognitive improvement of children with mental disabilities. Sessions without the dolphins were conducted out of sight of the dolphins at a nearby beach, and the reinforcement for a correct response was the child's favorite water toy.

Significant improvements in responses occurred when interaction with dolphins was used as reinforcement, compared to responses made when reinforcement was a favorite toy. Water work with dolphins evoked both a greater number and higher level of responses.

Reference:
Nathanson, D. E., & de Faria, S. 1993.Cognitive improvement of children in water with and without dolphins . Anthrozoös, 6, 17-29

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A fundamental characteristic of higher levels of consciousness is the awareness of one's own thoughts and feelings. Do dolphins have this kind of awareness? This was the question addressed in a study by Jonathan Schull of Haverford College and David Smith of the New School for Social Research.

In the experiment, the dolphin, Natua, heard either a variable low tone or a high tone, and learned to press corresponding paddles. Natua had no difficulty with most of the trials. But on some trials, the variable tone would approach the pitch of the high tone, which made it difficult to determine if it was to be considered high or low. These crucial trials were too difficult for the dolphin to be sure of success. On these trials, the dolphin could make a special response to ask for an easier trial, but it would only make sense to do that if he KNEW that he DIDN'T KNOW THE ANSWER.

Schull and Smith pointed out that by "bailing out" of these most difficult trials, Natua demonstrated that he was aware of his own doubts, that he could think about his own thinking. This ability is known as metacognition. The data produced was comparable to that collected for humans and rhesus monkeys.

Reference:
Smith, J.D., Schull, J., Strote, J., McGee, K., Egnor, R., and Erb, L. 1995. The uncertain response in the bottlenose dolphin (Tursiops truncatus). Journal of Experimental Psychology, 124:391-408.

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DRC has always believed strongly that programs that allow guests to enter the water to swim with dolphins should be specifically directed by experienced trainers. We structure our programs accordingly. This belief was verified by an independent study published in 1995, which concluded that programs like ours do not pose any significant risks to dolphin or human participants.

Reference:
Samuels A., and Spradlin, T.R. 1995. Quantitative behavioral study of bottlenose dolphins in Swim-With-Dolphin programs in the United States. Marine Mammal Science. 11: 520-544

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Each dolphin is believed to have a unique, stereotypic whistle called a "signature whistle". The individual whistle is developed during the first few months of life, and it has been observed that dolphins may imitate the signature whistle of a close companion. Because each dolphin produces a distinctive whistle, it may be possible for a dolphin to identify other individuals by their signature whistles. These whistles are thought to maintain contact between animals that are out of sight of each other.

Drs. Peter Tyack and Amy Samuels, along with Rebecca Thomas and Stephanie Watwood, all from Woods Hole Oceanographic Institution, investigated signature whistles and other vocalizations of our dolphins. They installed an array of hydrophones and an overhead video camera in our lagoons. With a special computer, underwater sounds were triangulated to pinpoint which individual was making a particular sound. Behavioral observations of the dolphins provided social context for these whistles in the unique natural environment at DRC.

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When we're not feeling well, a doctor may take a blood sample to try to determine why. Dolphins are no different. Veterinarians can tell a great deal about the health of a dolphin by analyzing a blood sample. However, the information known about dolphin blood samples is less detailed than what we know about human blood. DRC worked with Dr. Jeffery Stott, an immunologist from the University of California at Davis, in order to learn more about dolphin immunology blood profiles. Whereas veterinarians can typically detect an active infection in a dolphin by counting the number and type of white blood cells present in a blood sample, Dr. Stott is creating a complete immunological profile that includes the analysis of each subtype of white blood cell as well as how well those cells are functioning. Dr. Stott is collecting blood samples from dolphins that live in a variety of environments: DRC's natural seawater lagoons, aquariums, and the free-ranging dolphins of Sarasota, FL. By collecting blood from dolphins that live in each of these environments, he will be able to develop a very detailed profile of what is normal in each circumstance.

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