Captivity studies

Acoustic studies

Field studies
Dolphin (Tursiops truncatus) echoic angular discrimination: Effects of objects separation and complexity Branstetter, B. K., et al. (2007).

Cutaneous papillomaviral-like papillomatosis in a killer whale (Keiko) Bossart, et al. (1996).

PROJECT DEEP OPS: Deep Object Recovery with Pilot and Killer Whales Bowers, C.A. and R.S. Henderson, (1972).

Reintroduction to the wild as an option for managing Navy Marine Mammals Brill, R.L. and W.A. Friedl (1993).

In Search of Marine Mammals Claridge, D., K. C. Balcomb (1993).

Preliminary report to Jerye Mooney, Fund for the Animals, Re: Keiko-Reino Aventura, Mexico City, Mexico 7/08/93 Cornell, L (1993).

A Review of the Releasability of Long-Term Captive Orcas Garrett, H. (1998).

Intelligence and rational behavior in the Bottlenosed Dolphin. Herman, L. M. (2005).

The Bottlenosed Dolphin's (Tursiops truncatus) Understanding of Gestures as Symbolic Representations of its Body Parts. Herman, et al. (2001).

Observations of Disparity Between Educational Material Related to Killer Whales (Orcinus orca) Disseminated by Public Display Institutions and the Scientific Literature Hoyt, et al.(1994).

Evidence of Lethal Mosquito Transmitted Viral Disease in Captive Orcinus orca Jett, John, et al.(2012).

Do Zoos and Aquariums Promote Attitude Change in Visitors? A Critical Evaluation of the American Zoo and Aquarium Study Marino, Lori, et al.(2010).

The Captivity Industry - The Reality of Zoos and Aquariums Marino, Lori, et al.(2009).

Summary Report of Evaluation Panel Convened to Assess the Health of Keiko-January 28, 1998 McBain, et al.(1998).

Rehabilitation and release of marine mammals in the United States Moore, Michael, et al. (2007).

Echolocation by killer whales (Orcinus orca) while in pursuit of live fish Newman, K., H. Markowitz (1993).

The dolphin's (Tursiops truncatus) understanding of human gazing and pointing: Knowing what and where. Pack, A. A. & Herman, L. M. (2007).

Mirror self-recognition in the bottlenose dolphin: a case of cognitive convergence Reiss, D., and L. Marino (2001).

From captivity to the wild and back: An attempt to release Keiko the killer whale Simon, M. et al. (2009).

Survival of five species of captive marine mammals Small, R. and D. DeMaster (1995a).

Acclimation to captivity: a quantitive estimate based on survival of bottlenose dolphins and California sea lions Small, R. and D. DeMaster (1995b).

Big Star All at Sea Valentry, Duane (1969).

Experimental return to the wild of two bottlenose dolphins Wells, R. S., et al. (1999).

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Branstetter, B. K., Mevissen S. J., Pack, A. A., Herman, L. M., Roberts, S. R., and Carsrud, L. K. (2007). Dolphin (Tursiops truncatus) echoic angular discrimination: Effects of objects separation and complexity. Journal of the Acoustical Society of America, 121, 626-635.

A bottlenose dolphin was tested on its ability to echoically discriminate horizontal angular differences between arrays of vertically oriented air-filled PVC rods. The blindfolded dolphin was required to station in a submerged hoop 2 radial m from the stimuli and indicate if an array with two rods (S+) was to the right or the left of a single rod (S-). The angular separation between the two rods (thetaw) was held constant within each experiment while the angle between the S+ and the S- stimuli (thetab) varied to produce angular differences (Deltatheta=thetab-thetaw) ranging from 0.25 to 4. In experiment I, thetaw was maintained at 2 and in experiment II, thetaw was maintained at 4. Resulting 75% correct thresholds (method of constant stimuli) were 1.5 and 0.7, respectively. The two main findings of this study are: (1) decreasing the number of targets does not aid in localization, and (2) increasing the space between the rods enhances localization. Taken as a whole, the experiments suggest dolphins have a well-developed ability to resolve spatial information through sonar.
Reprint pdfs may be obtained from Brian Branstetter at or from Adam Pack at


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Bossart, G. D., C. Cray, J. L. Solarzano, S. J. Decker, L. H. Cornell, N. H. Altman (1996). Cutaneous papillomaviral-like papillomatosis in a killer whale (Orcinus orca). Marine Mammal Science, Vol. 12:2, p. 274-281.

Quote: "In this report, we document the first case of cutaneous papillomaviral-like papillomatosis in a killer whale. An approximately 10-yr-old male killer whale of Icelandic origin ("Keiko") developed bilateral axillary skin lesions soon after its arrival at a Mexico City oceanarium in 1985." ..."Studies are underway to characterize this presumptive viral disease and to address the potential immunological aspects of its pathogenesis. These studies include evaluation and characterization of the physiological and immunological status of the whale, isolation and characterization of the papilloma-associated virus, and subsequently the design and implementation of potential treatment regimens."

Note: This report is noteworthy because it mentions the word "virus" in the title ("papillovaviral-like") and throughout the paper, and it states that this virus is the "first case" found in a killer whale, strongly suggesting that Keiko was infected with a virus foreign to wild populations, without quite stating clearly that Keiko actually carried any virus. At the time the paper was written many spokespeople for the marine park industry were stating publicly that Keiko should never be released because he carried a contagious virus that could infect wild populations. In 1993, prior to this report, one of its authors, (Cornell), had written a report stating that Keiko's skin problems were the result of environmental stresses and not related to any virus. In 1998, after Bossart, et al.'s report was published, a group of six veterinarians and specialists appointed by the USDA examined Keiko and found him negative for 48 suspected viruses. (See USDA) report, below.) Bossart, et al.'s frightening viral theory was apparently incorrect.


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Bowers, C.A. and R.S. Henderson, (1972). PROJECT DEEP OPS: Deep Object Recovery with Pilot and Killer Whales. NUC TP 306. Undersea Surveillance and Ocean Sciences Department, Naval Undersea Center, San Diego, CA. Unclassified, 86 pp.

Note: Describes in detail the US Navy program from 1968 to 1971 for two male killer whales (Ahab and Ishmael) which were captured in Puget Sound, WA and airlifted to Point Mugu, CA, and later to Kaneohe, HI. Both killer whales were maintained at NUC Hawaii in fenced ocean pens, "...with low maintenance costs and excellent animal health." By September 1970, both whales had attained "open ocean reliability," wherein they would accompany a vessel out to sea an average of five times per week for a round trip distance of 10-12 nautical miles, typically swimming alongside the vessel at speeds of 6-7 knots. Ishmael on 19 February 1971 did not respond to his underwater recall signal and apparently swam away. On 8 June 1971, Ahab went on a 24 hour excursion ranging over 50 nautical miles in a northwesterly direction along the Oahu coast, and no further sea trials were conducted with him. Ahab died in 1974 at an estimated age of 15-16.


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Brill, R.L. and W.A. Friedl (1993). Reintroduction to the wild as an option for managing Navy Marine Mammals. Technical Report 1549, Naval Command, Control and Ocean Surveillance Center, San Diego, CA, 92152-5001.

Note: In 1992, as part of a cost-cutting effort, Congress became aware that the US Navy held over fifty "surplus" dolphins. This report documents the results of a study group formed to satisfy a Congressional request to "...develop training procedures which will allow mammals which are no longer required for this project to be released back into their natural habitat..." Instead, the group concluded: "There is no compelling scientific reason for reintroducing nonendangered species. Proven methods of operant conditioning can be used to prepare marine mammals for reintroduction to the wild. The success of reintroducing marine mammals to the wild, however, depends upon resources, methodologies, and technologies which do not currently exist. The success of a Navy reintroduction program would depend on developing technologies for monitoring and tracking reintroduced animals to quantify the success of the effort. Such technology does not exist and its development is estimated to take at least 2 years. In terms of cost effectiveness, the lifetime care and maintenance of the animals is preferable to reintroduction."

Note: The methodologies and technologies for reintroduction did exist (See Mate, 1989a, below) and they were published and available as of the drafting of the Navy report.


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Claridge, D., K. C. Balcomb (1993). In Search of Marine Mammals. Bahamas Naturalist, Vol 7:1 p. 11-17.

Note: In addition to a general survey of marine mammals of the northern Bahamas, this article discusses Bahama Mama, an adult female bottlenose dolphin inadvertently released to her assumed native habitat in 1992 after at least seventeen years of captivity. No official followup occurred, however this dolphin was positively photo-identified up to eight months after release in the company of wild dolphins in the Bahamas. This reintroduction, with no preparation, although not an example for future releases, gives reason for confidence in the species' ability to readapt to natural conditions.


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Cornell, L (1993). Preliminary report to Jerye Mooney, Fund for the Animals, Re: Keiko-Reino Aventura, Mexico City, Mexico 7/08/93 .

Quote: "This male orca, now about 10 to 12 years of age has been examined by several veterinarians in the past year or so to determine his health status and to establish his value for purchase by their aquariums and marine zoological parks. Keiko has been held in a small pool for these past years, one which could not meet even the meager standards and guidelines of the United States Department of Agriculture (USDA).

"The question now is how long can the whale survive in this facility and where will he go if removed from Mexico City?

"To their credit the owners and curatorial and training staff at Reino Aventura realize the animal is in improper conditions and have repeatedly asked other zoological facilities for their help in relocating him as they have not the money to build him new pools and life support systems as would be needed to secure his future. Until now they have repeatedly been refused in their attempts to sell or relocate him because he suffers from skin conditions which appear to be viral pappilomatous masses at the axillary area on both pectoral fins and another similar lesion on his tail stock anterior to his flukes. If these lesions are indeed viral, and his history would indicate they might be, his contact with other orcas and perhaps other animals of any kind could place those animals in jeopardy of exposure and possibly infection by the same virus(s) until he has been cleared up, assuming this is a virus which is not already endemic in these animals and which is obvious in Keiko because of his environment.

"The results of the clinical blood values and the tissue samples will not be available to us for some days, so for this preliminary report we will evaluate the animal solely on the basis of his history and our examinations, both behaviorally and physically.

"Keiko is, as we have pointed out, a male orca captured in the North Atlantic by Icelandic fishermen in about November of 1983. Judging by his alleged capture size he was about a yearling at that time plus or minus a year.

"After his capture, he was placed in a facility in Canada along with several other orcas and maintained in training as a future show animal until his sale to Reino Aventura in 1985. He is remarkably well adapted to his situation in that he is completely docile, well trained, under the circumstances and appears to be very well liked by the staff. And he appears to like the staffs of trainers as well. He is very responsive to them even when he is not hungry. He is approximately 20 feet in length and weighs only about 5000 pounds, considerably small of stature for an orca of his age and sexual maturity. He is unusually alert and is accompanied in his small shallow pool by a male bottlenosed dolphin which has not yet shown signs of skin diseases despite his continued daily environmental and physical contact with Keiko. Keiko eats only a small amount -120 pounds of food each day- due to the excessively high water temperatures in his pool (average 75-80 plus degrees fahrenheit). These excess temperatures-killer whales are usually found in water temperatures below 60 degrees F-are also responsible for his thin stature as there is no need for extra blubber to maintain warmth in this heat, instead his problem is how to stay cool as is evidenced by the daily lethargy which overtakes the animal as each day progresses in warmer weather. His teeth are worn down from rubbing on hard surfaces and are about 50% to the gum line at the anterior third of his jaws both top and bottom.

"The most significant findings of the physical examination other than his small size and teeth are the proliferative skin lesions at his axillary region and tail stock and the overall poor condition of his skin generally which is solely the result of the improper mix of salt in his pool. The lesions are very rough and bumpy in texture and are spreading again, at this time despite the extensive previous treatments with autogenous vaccines made from tissues removed from the whale. He has also been treated with large doses of immune response stimulants to no great permanent avail.

"According to the records shown to me, Dr.S Solorzano remarked at the small skin lesions at the base of both pectoral fins shortly after the whale's arrival mexico in 1985, this would indicate a chronicity of some determination. That there have been several extensive and time consuming attempts to "cure" Keiko indicate there is not likely to be an answer to his problem in his present situation and facility. Thus, if the whale is to be saved, rehabilitated and released, his facility must be rebuilt to modern, state of the art conditions which is not likely due to the owners' lack of funding, or, he must be moved somewhere with high quality cool sea water. This means some effort on the part of those interested parties. In the past several people have seen or reported lesions similar to this in orcas in captive environments. All of these have been in man made sea water save one. All facilities involved were of questionable water quality at the time the lesions were seen. All except this one have at this writing been cleared up, apparently spontaneously, after the water quality problems involved were addressed. (I would not be surprised to have, some day, a report of these lesions naturally occurring in young wild killer whales as we have already seen with walrus and sealions).

"Thus, to save Keiko one must first rebuild his existing pools or locate a facility willing to take the whale which has cool natural sea water as its source. The animal, once in such a facility, will likely improve its skin condition spontaneously, in time, with the retrieval in its body of the natural trace elements he now lacks and he will also gain weight accordingly, when no longer stressed and challenged by the chronic heat loss problems he now faces.

"There is no doubt that whales and dolphins can successfully be released to the wild. Many people have been involved in such releases in the past, some on purpose and some accidentally.

Lanny H. Cornell, DVM

Addendum to Keiko summary:

"The histopathology report done by routine histology is non commital about infection either by bacteria or viruses. The pathologist reports he believes the skin reaction to be the result of continued insult by chemical exposure, and states he has seen this previously in whales but does not give particulars

"The electronmicroscopy report has been slow coming in as they usually are. The pathologist here reports he sees no viruses but does see numerous bacterial colonies in the tissues submitted. The tissues were taken by scalpel from the most active parts of the lesion nearest the junction with normal skin tissue visually. This is normally where one would see the invasive organism(s) and would be the best place to judge the kind of confection present. Thus, one would have to believe we are dealing with a contact dermatitis here, caused by some external source and secondarily invaded by bacteria. If this were primarily a virus or a bacterial infection one would find the causative organisms all over the wounds instead of just in some areas as we see here (emphasis added).

"Conclusions: It would appear we are dealing with an iatrogenic disease. Probably this problem is the result of chronic water quality and/or environmental problems in the animal's water and could be corrected on site through the expenditure of a proper water filtration and treatment plant, or more likely, since they have had the animal there for some years and done nothing to change their water system, by moving the animal to a proper location with viable water quality for killer whales.


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Herman, Louis M. (2005). Intelligence and rational behavior in the Bottlenosed Dolphin. In Rational Animals, Susan Hurley and Matthew Nudds, editors.
A rational animal is defined as one that can perceive and represent how its world is structured and functions, and can make logical inferences and draw conclusions that enable it to function effectively and productively in that world. Further, a rational animal is able to incorporate new evidence into new perspectives of the world and can then modify its behaviours appropriately—in effect creating a new or revised model of the world in which it is immersed. Rational behaviour is necessarily built on the bedrock of general and specific intellectual capacity. Intelligence, a multidimensional trait, may appear to various degrees in various behavioural, cognitive, or social domains. Data and observations are presented on dolphin cognitive performance and on apparent rational responses within four intellectual domains within the context of a variety of empirical studies that we have conducted. These domains are: (a) the declarative (semantic or representational) domain (does the dolphin display knowledge or understanding about things?); (b) the procedural domain (does the dolphin exhibit competency in means, operations, or methods?); (c) the social domain (does the dolphin reveal social awareness and appropriate responsiveness in social interactions or relations?); and (d) the domain of the self (does the dolphin exhibit knowledge or awareness of itself?). In each case, the particular experimental paradigms are briefly outlined and instances of apparent inferenctial or creative acts within each paradigm are given. Read the full chapter here (715kb .pdf file).


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Herman, L. M., Matus, D. S., Herman, E. Y. K., Ivancic, M., and Pack, A. A. (2001). The Bottlenosed Dolphin's (Tursiops truncatus) Understanding of Gestures as Symbolic Representations of its Body Parts. Animal Learning & Behavior, 29, 250-264.
We assigned gestural symbols to nine different body parts of a bottlenosed dolphin (Tursiops truncatus) (rostrum, mouth, melon, pectoral fin, dorsal fin, side, belly, genitals, tail). The dolphin was first trained to touch any floating object it chose with the body part indicated by a gestural symbol. In Experiment 1, we tested the dolphin's ability to now touch specific gesturally referenced objects using specific gesturally referenced body parts. In Experiment 2, we tested its ability to either touch or toss gesturally referenced objects with gesturally referenced body parts, or to simply display those body parts, or shake them back and forth. The acts of touching, tossing, displaying, and shaking were each associated with specific gestures and appeared in random sequences within test sessions. The results demonstrated highly significant levels of performance throughout these tasks, including many successes on the first occasions of new body-part uses. These findings provided strong evidence that the gestural symbols we used for body parts were semantically processed and understood by the dolphin as representing those body parts. In addition, the dolphin's ability to use its different body parts in the same way (e.g., touching objects with each of the nine referenced body parts), and to use the same body part in different ways (e.g., displaying or shaking its dorsal fin, or touching or tossing objects with its dorsal fin), suggested a body-image representational system for conscious awareness and conscious control of body parts similar to that postulated for humans and revealed through human brain lesion studies.
Reprints are available from:

Louis M. Herman
Kewalo Basin Marine Mammal Laboratory
1129 Ala Moana Blvd.
Honolulu HI 96814


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John Jett, Jeffrey M. Ventre, Courtney S. Vail (2012). Evidence of Lethal Mosquito Transmitted Viral Disease in Captive Orcinus orca Florida Marine Mammal Health Conference.
Two recently discovered studies document the presence of viral diseases carried by a mosquito vector in captive killer whales, Orcinus orca. In both cases, the transmission of these diseases was implicated in the cause of death for these animals. In the first case, a 25-year-old male orca, Kanduke, died suddenly and unexpectedly in the summer of 1990 at Sea World of Florida in Orlando. The necropsy in this instance identified the St. Louis encephalitis virus as the cause of death. Buck et al (1993) subsequently wrote a peer-reviewed paper describing the presence of this avian virus in the tissue of Kanduke. In the second case , a 14-year-old male orca, Taku, also died suddenly and without notable premonitory signs of illness in 2007 at Sea World of Texas in San Antonio. The necropsy in this case confirmed the presence of West Nile Virus in brain tissue and suggested the observed pathologies were consistent with those caused by West Nile Virus in other animals.

This initial evidence suggests a direct causal link between orcas maintained in public display facilities and premature death due to viruses transmitted through a mosquito vector. Further analysis is required to determine the presence of, and exposure to, these viruses in captive cetacean populations and stemming from the shallow and static environments where loafing and other surface behaviors increase susceptibility to transmission through mosquito bite. The West Nile Virus has been isolated in some populations of wild dolphins who may be similarly susceptible as a result of sustained surface behaviors in shallower coastal waters. Additionally, anecdotal eyewitness reports of mosquitoes being observed on the dorsal surfaces of killer whales in a captive environment reveals the additional risks associated with confinement and housing of this species in subtropical environments.

The occurrence of avian-borne viruses in captive killer whales requires further inquiry, and suggests the possibility of such viruses in other cetaceans maintained in captivity. This information is critical to the debate about keeping cetaceans in captivity and may provide additional explanation for past or future illnesses and death in these facilities. Free-ranging, wild killer whales are not stationary and suspended with their dorsal surfaces exposed for extended periods of time, thereby providing an opportunity for transmission via mosquitoes carrying avian viruses. No data has been found that documents these diseases in their wild counterparts.


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Marino, Lori, Scott O. Lilienfeld, Randy Malamud, Nathan Nobis and Ron Brogliod (2010). Do Zoos and Aquariums Promote Attitude Change in Visitors? A Critical Evaluation of the American Zoo and Aquarium Study. Society and Animals 18 (2010) 126-138.
Modern-day zoos and aquariums market themselves as places of education and conservation. A recent study conducted by the American Zoo and Aquarium Association (AZA) (Falk et al., 2007) is being widely heralded as the fi rst direct evidence that visits to zoos and aquariums produce long-term positive eff ects on people’s attitudes toward other animals. In this paper, we address whether this conclusion is warranted by analyzing the study’s methodological soundness. We conclude that Falk et al. (2007) contains at least six major threats to methodological validity that undermine the authors’ conclusions. Th ere remains no compelling evidence for the claim that zoos and aquariums promote attitude change, education, or interest in conservation in visitors, although further investigation of this possibility using methodologically sophisticated designs is warranted.See full paper HERE.


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Marino, Lori, Gay Bradshaw and Randy Malamud (2009). The Captivity Industry - The reality of zoos and aquariums BEST FRIENDS MAGAZINE March/April 2009.
Millions of people visit zoos, marine parks and aquariums every year. Ostensibly, these places provide an opportunity to look at, connect with and appreciate the beauty and behavior of the animals. Indeed, everyone is drawn to the majesty and mystery of animals who look and live so differently than we do, but nonetheless seem so similar to us. But more is going on than meets the eye. Exactly what are we learning about other animals in these places? How is the zoo experience different for the animals than it is for the visitors? And what might we learn about ourselves by casting a more examining eye on the institution of zoos and aquariums?
Most zoo visitors don’t think about what it means that the animals on display have been removed from their native habitats. When they do think about it, people often come to the conclusion that captivity is a necessary evil: Zoos and aquariums are necessary because it is important for people to be able to look at other animals and because this human experience actually helps other animals in the wild. Subsequently, the price we pay for this (or, more accurately, the price the animals pay) is justified.
But this rationalization sidesteps a fundamental question: Why do zoos exist in the first place? How did they begin? To understand why zoos endure so tenaciously in Western culture, we need to look at their historical origins.
Full article HERE.


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McBain, et al. (1998). Summary Report of Evaluation Panel Convened to Assess the Health of Keiko-January 28, 1998.

Panel Members:

Dr. James McBain, Sea World, Inc.
Dr. Al Smith, Oregon State University
Dr. Jeffery Stott, University of California at Davis
Dr. Joseph Geraci, National Aquarium in Baltimore
Mr. Bud Krames, Dolphin Quest
Dr. Barbara Kohn, USDA, APHIS, AC - Facilitator

Other Contributors:

Dr. Isis Johnson, USDA, APHIS, AC
Dr. Randy Ridenour, USDA, APHIS, AC

This independent evaluation was done with the full backing and support of the Free Willy Keiko Foundation. Foundation liaisons were Mr. Joseph Gaskins and Mr. Robert Ratliffe.

The Panel wishes to thank the staff at the Free Willy Keiko Foundation and the Oregon Coast Aquarium for their cooperation with this evaluation. The Panel was welcomed with open arms. We wish to thank Dr. Lanny Cornell for his cooperation.

Keiko, a male killer whale, Orcinus orca, was transported to the United States and housed at a newly built facility within the Oregon Coast Aquarium (OCA) in January 1 1996. Since that time the animal has been under the care of the OCA and the Free Willy Keiko Foundation (FWKF). Due to the history and popularity of the whale, his health and well being have been subjected to a high degree of public and media scrutiny. In August 1997, after a change in personnel handling the day-to-day care of Keiko and after conflicting reports of his health status, APHIS was asked to facilitate the formation of an independent panel of marine mammal experts who would assess the current health status of Keiko. This panel was formed in October 1997 with the cooperation of the FWKF. The panel included veterinary experts, including a virologist and immunologist, as well as two veterinary clinicians, a behaviorist, and an APHIS representative as a facilitator. The animal was evaluated by the panel members during December 1997 and January 1998.

Keiko is an approximately 18 year old killer whale whose living condition and health concerns came to light when he was chosen to star in the movie, Free Willy. At that time, Keiko resided in a facility in Mexico (Reino Aventura), in which the pool was small and water quality was poor including inappropriate temperature. Keiko has had no conspecific companionship since he resided in Canada, but he did have dolphin companionship at Reino Aventura. After several years of negotiations and attempts to move Keiko to a more appropriate facility, arrangements were made to move him to the OCA facility, which was leased by the FWKF. Keiko's health has been a constant concern with the most visible problem being a viral (assumed) skin condition which was visible even during the filming of the movie. The skin condition did appear to improve after the transfer to the Oregon facility with its improved water quality.

Keiko was examined by a marine mammal veterinarian and samples were obtained for generally accepted routine medical testing, including a complete blood count and chemistry profile. ...

Results and Evaluation:
To gain the best picture of the health status of any animal, one should monitor appropriate parameters over time, using repeated testing. This panel was formed to evaluate a "snapshot" of Keiko's medical and behavioral condition. To provide the best evaluation under these circumstances, the panel relied on the medical and behavioral records of the animal, as well as examinations and testing done in November 1997 through January 1998.

Based on clinical pathology results, there is a high probability that Keiko developed a hepatopathy beginning in June 1997. The primary manifestation of this event was a significantly elevated liver enzyme which did not return to normal until December 1997. Keiko was treated with an antifungal drug for a suspected lung infection during the latter period of enzyme elevation. This complicated interpretation of the enzyme values since the antifungal agent used is known to occasionally produce a transient elevation in liver enzymes, which may persist over a long period of time. The return of the liver enzymes to normal levels indicated that, in the very least, the condition is in remission.

During his residency in Oregon, Keiko experienced a tooth fracture which later required extraction. There have also been multiple episodes of hematuria. Recent urinalyses demonstrate that hematuria is no longer present. Dr. Lanny Cornell, attending veterinarian for the FWKF, indicated that Keiko has a penile lesion which was the likely source of blood in the urine. The lesion has healed. Observers have reported the occurrence of behaviors described as "cramping" and "twitching." The Panel's veterinary clinicians have not seen these behaviors, nor is any video available. As a result their cause and significance cannot be determined. The behaviors have been noted since Keiko's arrival in Oregon, and to date no disease condition has been associated with them.

In late December 1997, a small skin lesion on the leading edge of the right pectoral flipper was observed. It was approximately 1" in diameter and visually appeared to be a papilloma. The lesion was biopsied, and although cytopathology was evident on the first but not the second and third growth passages, histology and initial cell culture tend to support the growth being the result of a papilloma (wart) virus. This condition is known to occur in wild and captive whales and is not considered a health challenge to Keiko (emphasis added). Other skin lesions which have been observed on Keiko have been examined and biopsied when appropriate (fresh lesions). Although such lesions resembled possible viral skin lesions, no specific viral etiology has been identified (emphasis added).

Blood (serum and buffy coats) samples were subjected to rigorous viral isolation and/or viral antigen testing for 49 antigens, including 33 serotypes of caliciviruses (oceanic and nonoceanic), marine species virus isolates of herpes virus, rotavirus-like virus, entorvirus-like virus, retrovirus-like virus, and three adenoviruses, as well as other miscellaneous viruses, including morbillivrius, parvovirus, and human hepatitis virus, canine adanovirus, and LDH virus. Antibody testing for 48 of the 49 viruses is complete at this time. Antibody tests were negative, and there were no viruses isolated (emphasis added).

Samples collected to evaluate the immunological status of Keiko revealed that he has a low circulating B-lymphocyte count and a slightly elevated total immunogloubulin level. Immunealactrophoresis of the serum proteins indicated that there may be a missing isotype of IgG. However, the significance of this finding is unknown. T-lymphocyte function appears to be adequate in this animal.

Behavioral observations of Keiko indicate a variation in his behavior patterns. In December 1997, he appeared "frustrated" and not content. In January 1998, Keiko appeared calm, if bored. Both observers felt Keiko might be feeling the effects of not having any control over his environment. However, no stereotypic or destructive (typical neurotic behaviors such as head butting or staring into the walls) swimming or other behaviors were observed.

Keiko related well to his trainers, but it was felt that the response thresholds for the training sessions were low, and Keiko's response to stimuli, though not normal, was slow. The primary reinforcement tool preferred by Keiko was tactile stimulation after a session. He does not appear to be food driven in his interactions. Keiko was provided enrichment devices and interacted with them randomly, especially enjoying the high-powered water jets used for environmental enrichment.

Overall, Keiko appeared to have no behavioral problems that adversely affected his health. Several panel members expressed concern that Keiko, may not have a great deal of stamina and that even small body movements created visible movement of skin. This apparent flaccidity of Keiko's body could indicate insufficient muscle mass, lack of muscle tone, or recent changes in weight. Keiko continues to gain weight and grown since his move to Oregon.

APHIS inspections, conducted by a 2-person team, showed the facility in compliance with the AWA regulations and standards in July 1997 and December 1997.

Summary and Recommendations
There is no current indication that Keiko is ill. He showed no clinical pathological evidence of chronic deep-seated infection during his residence in Oregon. Immunological test results are apparently within known normal parameters, and there was no evidence of recent viral challenges to 48 different viruses. Keiko appeared to be exhibiting no abnormal behavior patterns. At the time of the study, Keiko was recovering from an illness (probable hepatopathy) of several months' duration. The only known chronic condition in evidence is probable papillomatosis. This snapshot analysis must be viewed as that-a look at one point in time. Questions and concerns about Keiko's long-term health status and options for his future need to be studied over a much longer period of time. Given Keiko's past health history and ongoing concerns and scrutiny of his health, the panel makes the following recommendations:

1. Continue monitoring and follow-up testing to further establish a baseline for Keiko's medical results and to provide reliable scientific documentation of his overall health picture.

2. Given Keiko's past health history and potential future plans, a written line of authority must be established, which assures that the husbandry and medical programs are integrated in a way which places a single person in ultimate authority. This will required commitment, cooperation, and communication between the husbandry staff, water quality engineers and operators, and veterinary care personnel.

3. Ancillary to "2" above, complete and useful medical, training, and feeding records are necessary for any future evaluation of Keiko's health. These records should be well organized and readable and provide an accurate picture of all tests, treatments and responses.

4. Keiko appears to have flaccidity in his body, evidenced by highly movable skin. This could bean insufficient muscle mass or lack of muscle tone. Keiko should continue a program to improve his body tone and endurance. Such a program should include, at least, a program of regular, increasing exercise, and monitoring of weight and appetite.

5. Although Keiko's dependence on human interaction may facilitate handling by the trainers, killer whales are social creatures and should be afforded interactions with same or other compatible marine species. Section 3.109 of the AWA regulations and standards requires such access. A companion animal is recommended and should be a compatible cetacean or, if necessary, pinniped species.

6. Any decision on the rehabilitation of Keiko should be made in concert with an ongoing, long-term health study and evaluation. An expert panel assembled by the responsible parties is recommended to oversee this task.

Note: This is reprinted in full because it clears up the confusion created by the claims that Keiko ever had a contagious foreign pathogen, as suggested by Bossart, et al., and because this panel provides a model process for examining any potential candidate for release or retirement in natural habitats.


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Moore, Michael Greg Early, Kathleen Touhey, Susan Barco, Frances Gulland, Randall Wells. (2007) Rehabilitation and release of marine mammals in the United States. Marine Mammal Science 23 (4), 731–750.
Rehabilitation of stranded marine mammals elicits polarized attitudes: initially done alongside display collections, but release of rehabilitated animals has become more common. Justifications include animal welfare, management of beach use conflict, research, conservation, and public education. Rehabilitation cost and risks have been identified that vary in degree supported by data rather than perception. These include conflict with fisheries for resources, ignorance of recipient population ecology, poor understanding of long-term survival, support of the genetically not-so-fit, introduction of novel or antibiotic-resistant pathogens, harm to human health, and cost. Thus facilities must balance their welfare appeal against public education, habitat restoration, human impact reduction, and other conservation activities. Benefits to rehabilitating marine mammals are the opportunity to support the welfare of disabled animals and to publish good science and so advance our understanding of wild populations. In specific cases, the status of a population may make conservation the main reason for rehabilitation. These three reasons for rehabilitation lead to contrasting, and sometimes conflicting, management needs. We therefore outline a decision tree for rehabilitation managers using criteria for each management decision, based on welfare, logistics, conservation, research, and funding to define limits on the number of animals released to the wild.


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Newman, K., H. Markowitz (San Francisco State University, San Francisco CA 94132) (1993). Echolocation by killer whales (Orcinus orca) while in pursuit of live fish. Abstract from Marine Mammal Conference.
Echolocation use by cetaceans has been postulated to be functional in a natural environment, but might not be used as frequently in a captive setting where the water is clear and the whales are handfed. The object of this study was to see if captive Orcinus orca used echolocation when presented with live fish. We fed live coho salmon (Onchorhynchus klautch) to two captive killer whales at Marine World Africa, U.S.A., Vallejo, CA. The experiment was videotaped and recorded on a high frequency Racal 4D store four-track tape machine at 30 inches per second. A hydrophone array, consisting of a B&K 8104, a B&K 8105 and a Magnavox, was used to receive the sounds. Recordings of echolocation clicks were slowed down and analyzed with a Kay Elemetrics DSP 5500 Sonagraph and a MacAdios sound analysis program.

Results of this study demonstrate that captive killer whales will pursue, capture, and eat live fish. The whales in this study used echolocation while in pursuit of fish, as well as at other times. Preliminary analyses of echolocation clicks reveal spectral energy up to 80 kilohertz.


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Pack, A. A. & Herman, L. M. (2007) The dolphin's (Tursiops truncatus) understanding of human gazing and pointing: Knowing what and where. Journal of Comparative Psychology, 121, 34-45.
The authors tested whether the understanding by dolphins (Tursiops truncatus) of human pointing and head-gazing cues extends to knowing the identity of an indicated object as well as its location. In Experiment 1, the dolphins Phoenix and Akeakamai processed the identity of a cued object (of 2 that were present), as shown by their success in selecting a matching object from among 2 alternatives remotely located. Phoenix was errorless on first trials in this task. In Experiment 2, Phoenix reliably responded to a cued object in alternate ways, either by matching it or by acting directly on it, with each type of response signaled by a distinct gestural command given after the indicative cue. She never confused matching and acting. In Experiment 3, Akeakamai was able to process the geometry of pointing cues (but not head-gazing cues), as revealed by her errorless responses to either a proximal or distal object simultaneously present, when each object was indicated only by the angle at which the informant pointed. The overall results establish that these dolphins could identify, through indicative cues alone, what a human is attending to as well as where.


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Reiss, D., and L. Marino (2001) Mirror self-recognition in the bottlenose dolphin: a case of cognitive convergence. Proc. Natl. Acad. Sci. USA 98:5937-5942.
The ability to recognize oneself in a mirror is an exceedingly rare capacity in the animal kingdom. To date, only humans and great apes have shown convincing evidence of mirror self-recognition. Two dolphins were exposed to reflective surfaces, and both dem- onstrated responses consistent with the use of the mirror to investigate marked parts of the body. This ability to use a mirror to inspect parts of the body is a striking example of evolutionary convergence with great apes and humans.
Entire paper as HTML file


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Simon, Malene, M. B. Hanson, L. Murrey, J. Tougaard and F. Ugarte. (2007). From captivity to the wild and back: An attempt to release Keiko the killer whale. Marine Mammal Science, July 2009.


A number of cetaceans have been released into the wild, with research or the improved welfare of the individuals in question as the main goal. In a few cases, releases have been monitored with methods such as telemetry or photo-identification (Gales andWaples 1993, Veit et al. 1997,Wells et al. 1998, Reynolds et al. 2000). As a rule, the animals released successfully into the wild had been captive for relatively short periods of time (e.g., 2 yr, Wells et al. 1998), were held in sea pens rather than concrete tanks, and some were released in the company of conspecifics (Veit et al. 1997, Wells et al. 1998). We describe here the last phases of a project aimed at releasing a single killer whale that had been captured as a calf, raised in tanks and kept isolated from conspecifics during most of his life. FULL PAPER HERE


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Small, R. and D. DeMaster (1995a). Survival of five species of captive marine mammals. Marine Mammal Science, Vol. 11:2, p. 209-226.
Survival in captivity was calculated for 1707 bottlenose dolphins (BD), 72 killer whales (KW), 73 white whales (WW), 3,090 California sea lions (CSL), and 47 Steller sea lions(SSL) based on data in the Marine Mammal Inventory Report (MMIR) of the NMFS. Mean annual survival rates (ASRs) between 1988 and 1992 were 0.951, 0.937, and 0.954 for BD, KW, and WW, respectively, and 0.952 and 0.969 for CSL and SSL, respectively. These estimates represent significant increases in survival for both BD and CSL over the last 5 yr. Using all of the MMIR data (1940-1992), the ASR of BD calves (less than 1yr of age) was significantly less than the ASR of non-calves (0.666 vs 0.946, P, less than 0.0001). Survival of captive-born CSL was significantly higher than those born in the wild (0.962 vs 0.945, P = 0.003), but the difference was not significantly different for BD (0.948 vs 0.944, P = 0.60). For non-calf BD and KW, captive animals survived at a slightly lower rate (BD 0.944 vs 0.961, P = 0.07; KW 0.938 vs 0.976 P less than 0.001) than animals in the wild (BD: Wells and Scott 1990, KW: Olesiuk et. al. 1990). Survival of captive non-pup SSL was slightly higher (0.968 vs 0.930) than animals in the wild (York 1994, life table analyses). Survival rates were significantly different among institutions for BD calves and non-calves, CSL pups and non-pups, and SSL non-pups.

Quote: Survival of the wild population Olesiuk et al. studied, based on approximately 250 non-calves, was significantly higher than our estimates for non-calf captive killer whales (0.976 vs. 0.938, P<0.001).


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Small, R. and D. DeMaster (1995b). Acclimation to captivity: a quantitive estimate based on survival of bottlenose dolphins and California sea lions. Marine Mammal Science, Vol. 11:4, p. 510-519.

Quote: "...over the 5-yr period between 1988 and 1992 compared with estimates based on data through 1987...Survival in captivity for killer whales Orcinus orca ...remained the same."

Note: This study plus more recent data indicates that survival in captivity for killer whales has not improved in recent years.


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Valentry, Duane (1969). Big Star All at Sea. Sea Frontiers, Vol 15:4, pp. 219-223.

Note: After almost eight years of captivity at Marineland of the Pacific, a twenty year old pilot whale named Bimbo was successfully reintroduced to the wild. Captured in January/February, 1960 at a length of 17' 6", he performed well for about three years. When his female pilot whale and dolphin companions died, Bimbo's behavior changed drastically. "One day he would be as friendly as ever, the next in a wildly agitated state or apathetic and apparently depressed." It was decided to keep him as an attraction whether or not he performed. After four years of treatment including antidepressant drugs and tranquilizers, Bimbo smashed into a window, flooding spectators. He was released in August, 1967 at a length of 20' 6", "...after much planning and weeks of isolation in a tank for physical tests to make sure he was fit for fending on his own at sea." He was resighted in 1969 near Santa Barbara, CA by a U.S. Navy collector, and again in 1974 near San Clemente identified from photographs by L Cornell and J. Prescott (pers. comm., John Prescott.)


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Wells, R. S., K. Bassos-Hull, K. S. Norris (1999). Experimental return to the wild of two bottlenose dolphins. Marine Mammal Science: Vol. 14:1, p. 51-71.
In the first scientific experiment of its kind, two young male bottlenose dolphins (Tursiops truncatus) were captured in Tampa Bay, Florida, and then returned to the wild at the same locale in October 1990, after two years in captivity. The dolphins' age/sex class and the capture and release site were selected prior to their collection. The ranging and social association patterns of the host community were examined prior to, and, including the two animals, after release. The dolphins remained together for the first month, then began interacting more with other dolphins and less with each other. Within the first year, one dolphin returned to the waters near his capture site and has remained there at least through September 1993. The other dolphin has remained in his original home range at least through June 1996. Observations of each dolphin have shown them to be fully integrated into the local dolphin societies. They displayed typical behavioral, ranging, and social association patterns. Their body condition has been excellent at each observation. They have not been observed interacting with humans. The apparent success of this experiment cannot necessarily be generalized to all potential candidates for return to the wild, but the results can be used to guide future experiments.





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