1. Bailey Franklin Oklahoma State University The National Aquarium at Baltimore

2. Internship Background I was selected for a Marine Mammal Training Internship by the senior trainers at the National Aquarium in Baltimore. I worked for a total of 127.5 hours- three weeks Monday through Friday during the month of July 2013. I was able to conduct my own research for this time on the aggression of the male dolphins. I was alone in my research and data collection, and was occasionally guided by my internship coordinator. 3. What is aggression? Aggressive behaviour, in the narrow sense of behaviour directed towards causing physical injury, often results in settling status, precedent, or access to some object or space. (Hinde) From psychological and sociological standpoints, aggression is regarded as intentional behavior aimed at inflicting pain and manifested by hostility and attacking behaviors. In contrast, biologists define aggression as behavior associated with attack or escalation toward attack, omitting any stipulation about intentions and goals. (Staaden, Searcy, and Hanlon) 4. What is aggression? Aggression in general is a difficult thing to define. There are many different and varying ideas on what defines aggression. For this study, (or any study) the scientist has to define aggression, and make clear what will be deemed as aggressive behaviors from the animals. 5. Operational definitions of aggression Chasing: When one dolphin begins a fast swimming behavior to follow the other that ends when the chasing dolphin arrives at the one being chased. Ramming: When one dolphin uses its head in a rostrum down position to forcefully attempt to displace the other. Fluking: When one dolphin uses its fluke to strike the other forcefully, or attempt to strike the other forcefully. 6. Operational Definitions of Aggression Sexual Behavior: When one dolphin gains an erection and makes a mating display toward the other. This is often a ventral-up thrust with the pelvic region towards the other dolphin from the underside, but can be a thrust from another angle depending on the location of the dolphins in the pool. Stealing Toy: When a dolphin takes control of the toy from the other dolphin who had previous control of it. 7. Operational Definitions of Aggression Vocalizing: When in a confrontation, or in combination with another aggressive behavior, one dolphin makes an audible sound. Jaw Popping: When one dolphin opens and closes its jaw in such a way that it makes a popping sound. Posturing: When a dolphin squares up with the other and forms his body into an S shape. 8. Operational Definitions of Aggression Biting: When one dolphin uses its teeth against the other in a confrontation. Fast Swimming: When one dolphin uses speed swimming to either evade or chase the other. 9. What is enrichment? the addition of one of more factors to a relatively impoverished environment in order to improve the physical/psychological welfare of the animal involved. These factors frequently refer to physical, social, design or management/ husbandry interventions that may improve the behavioral environment of captive animals. (Ellis) 10. Enrichment So, enrichment is anything added to the animals environment to improve it and make it more stimulating and exciting. 11. Hypothesis I predicted that in observation sessions with no enrichment added to the pool, the count of aggressive behaviors exhibited by the dolphins would be the lowest, while sessions with multiple toys added would be higher than no enrichment, but lower than shared toy enrichment, and shared toy enrichment would show the highest count in aggressive behaviors from the two dolphins. 12. Predictions no enrichment < multiple toy < shared toy No toys will lead to less aggressive behaviors The presence of toys will increase aggression 13. Methods Three times a day, I would conduct thirty minute observation sessions of the two male dolphins. Depending on their location in the three pools, I would either sit in the pit or at the underwater viewing area to watch them. During these sessions, I would tally aggressive behaviors I witnessed on a chart, while recording general behavior observations in a notebook. 14. The pit 15. Methods SessionType: Time: Pool: Dolphin Behavior: Chasing Ramming Fluking SexualBeh. StealingToy Vocalizing JawPopping Posturing Biting FastSwimming Gate Ramming Beau Foster 16. Methods Each of the three daily observation sessions was designated to a specific type of enrichment: no enrichment, shared toy enrichment, or multiple toy enrichment. There was no pattern in the session choice, it was random. 17. Multiple toy For multiple toy enrichment, I chose to use four hula hoops from the toy collection at the National Aquarium in Baltimore. Of all the hoops, I randomly chose four for each session. The hoops were not the same for each session. 18. Shared toy For shared toy enrichment, I chose to use a felt blanket. There are two at the aquarium. If it was available, I chose the green one. If it was not, I chose its blue counterpart on the same dimensions, but different color. 19. No enrichment In no enrichment sessions, all toys of any kind were removed from the pool. 20. Study site I studied the two male dolphins housed at the National Aquarium in Baltimore. My observation location was most frequently the pit- an observation site with windows looking into all three pools (not the medical pool). I stayed in the pit if the dolphins were in HP1 or HP2 (the two back pools not available to the public). If the dolphins were in EP (the front pool used for presentations) I watched them from the underwater viewing area also available to the public. 21. The National Aquarium 22. Subjects Beau and Foster, the two male dolphins housed at the aquarium. Beau is 8 and Foster is 5. 23. Methods To interpret the data from all the sessions, I entered all session tallies into an Excel spreadsheet. Behavior Totals Type of sessionPool Time Chasing Ramming Fluking Sexual BehaviorStealing ToyVocalizingJaw PoppingPosturing Biting Fast SwimmingGate RammingTotal Aggressive Behaviors forSession 2-Jul N.E. 11:00-11:30 0 1 0 0 0 0 0 0 0 3 0 4 S.T.E. 1:25-1:55 10 20 4 15 15 0 0 0 0 6 0 70 Total M.T.E.= 541 3-Jul M.T.E. HP2 9:12-9:42 7 5 0 0 1 3 1 0 2 2 0 21 Total S.T.E.= 1336 N.E. FP 1:19-1:49 0 0 0 0 0 0 0 0 0 0 4 4 Total N.E.= 610 S.T.E. HP1 2:18-2:48 11 7 3 7 14 4 0 0 2 4 0 52 4-Jul M.T.E. FP 9:15-9:45 1 0 0 0 0 3 2 0 0 0 4 10 N.E. HP2 11:02-11:32 2 1 7 0 0 2 0 0 0 0 1 13 S.T.E. HP2 3:25-3:55 13 7 4 35 13 0 0 0 0 2 0 74 5-Jul S.T.E. HP2 10:00-10:30 16 7 7 33 16 0 1 0 1 3 0 84 N.E. HP2 1:05-1:35 2 0 0 0 0 2 0 0 0 5 1 10 M.T.E. HP2 3:55-4:25 0 6 10 5 0 28 16 0 0 19 0 84 Foster 24. Methods After completing the spreadsheet, I added up all same- session totals, and individual aggressive behavior totals to analyze the data. I excluded data from the first day of observations because on the first day (7/2) I only observed the dolphins twice, once with a shared toy and once with no toys. 25. Results and data 26. Results and data 27. Results and data 28. Results and Data Percent Totals: Chasing- 4.38% Ramming- 9.81% Fluking- 9.05% Sexual Behavior- 38.14% Stealing Toy- 10.48% Vocalizing- 14.43% Jaw Popping- 7.52% Posturing- 0.05% Biting- 2.76% Fast Swimming- 2.90% Gate Ramming- 0.48% 29. Results and Data Percent Totals: Chasing- 4.72% Ramming- 17.34% Fluking- 9.72% Sexual Behavior- 27.33% Stealing Toy- 10.19% Vocalizing- 18.51% Jaw Popping- 6.99% Posturing- 0.00% Biting- 0.74% Fast Swimming- 5.04% Gate Ramming- 1.17% 30. Results and Data 31. Results and Data Beaus session totals: Total Multiple Toy Enrichment - 506 Total Shared Toy Enrichment- 1132 Total No Enrichment- 417 32. Results and Data 33. Results and Data Foster Total Multiple Toy Enrichment- 541 Total Shared Toy Enrichment- 1336 Total No Enrichment- 610 34. Results and Data 35. Discussion I had predicted that the aggressive totals per session would be: No enrichment < multiple toy < shared toy For Beau, this was true. For Foster, this was not true. So, my hypothesis was incorrect 36. Discussion Beaus data shows that he most frequently exhibited sexual behavior (38.14% of total aggressive behaviors recorded) This could be because he is getting older, and beginning to reach sexual maturity (Atlantic Bottlenose dolphins usually reach sexual maturity between ages 10 and 15) 37. Discussion Beau was the dolphin who held control of the toys most of the time within the sessions. This could be attributed to Beau being the more dominant male of the two. Foster has more rake marks -rake marks are defined as scarring on the bodies of dolphins caused by other dolphins biting them or raking their cone shaped teeth across the skin -rake marks are a defining factor when determining social status; more rake marks would equal a lower ranking Foster had less toy control 38. Discussion In Amazon River Dolphins, the dominant males often are observed carrying objects as a form of socio-sexual display (Martin, Silva, and Rothery). This could be another contributing factor to Beaus assertion of ownership of the toys 39. Discussion Beaus data also showed that he exhibited most aggressive behaviors in shared toy sessions, and least in no toy sessions Shared toy> multiple toy> no toy 40. Discussion Fosters data shows that he also exhibited sexual behavior most frequently (27.33% of total aggressive behaviors recorded) Most of Fosters sexual behavior was in response to Beau Sommer and Vasey suggest that homosexual encounters in bottlenose dolphins could be another form of socio-sexual behavior that builds a stronger bond between two male dolphins 41. Discussion Foster exhibited the most aggressive behaviors in sessions with a shared toy, but exhibited the least in sessions with multiple toys, voiding my hypothesis. Shared toy> no toy> multiple toy Foster showed more aggressive behaviors overall with a total of 2561, while Beau had a recorded total of 2100. 42. Influencing factors Many outside factors could have easily played a part in my study. These variables could have affected the dolphins behavior during observations. Female dolphins being consistently in a neighboring pool Trainers and staff walking around the pools and interacting with the females Time of day- energy level could vary Audience members present at all times Feeding schedule- hunger driven behavior Frequency of enrichment Desensitization to the toys- novelty factor Divers in neighboring pools Environmental conditions Myself in the pit window 43. Limitations Limitations of this study include the things that have had an affect on the outcome. My own observation skills Pool visibility Inability to discern the vocals of the dolphins Differentiating between aggressive behavior and non- aggressive behaviors Time Variable control 44. Problems Things being prematurely thrown into the pool before an observation session was finished There were several times the dolphins were completely out of my line of vision I counted a total of 143 minutes when the dolphins were out of my sight, that is approximately 4.33 minutes per 30 minute session where I could not observe them or record behaviors Variable control Pool inconsistency Time inconsistency 45. Suggestions Keep all controllable variables consistent In a perfect world- pool would stay the same, toys would be precisely the same, schedule would not change Keep male dolphins completely isolated from outside interference Longer study time Have multiple researchers viewing the dolphins from different points around the pool Learn individual dolphin sounds and use sound equipment to better track vocalizations 46. Further Study Repeat aggression study with optimized conditions and longer timeline Aggression and Toy color Female aggressive behaviors Aggression with a socio-sexual focus 47. Conclusion My hypothesis proved incorrect, as both the males did not follow the pattern of Shared toy> multiple toy> no toy Sexual behaviors was the most common form of aggressive behavior observed Conditions for study could be improved in future research Shared toy did, however, elicit the most aggressive behaviors 48. Citations Hinde, R., 1969, The Basis of Aggression in Animals, Journal of Psychosomatic Research,v.13, p.213-219. Van Staaden, M.J., Searcy, W.A., Hanlon, R.T., 2011, Signaling Aggression, Advances in Genetics, v. 75, p. 23-49. Ellis, S. LH., 2009, Environmental Enrichment: Practical Strategies for Improving Feline Welfare, Journal of Feline Medicine and Surgery, V. 11, p. 901-913. Martin, A.R., da Silva, V.M.F., Rothery, P., Object Carrying as a socio-sexual display in an aquatic animal, Biology Letters, v.4, p. 243-245. Sommer, V., and Vasey, P.L., 2006, Cambridge University Press, Cambridge, Cambridge, MA, 382 p.