Why Animal Rights Activists are Wrong about Zoos and Aquariums

An In-Depth Look at the Animal Rights Industry’s Allegations Against Zoos and Aquariums

Deceptive Anti-Zoo Campaigns Undercut Support and Critical Funding for Wildlife Conservation, Put Animals at Risk, and Are Not Based on Science or Animal Welfare

Over the last several years, a number of animal rights activist groups, including People for the Ethical Treatment of Animals (PETA), the Humane Society of the United States (HSUS), and the lesser known World Animal Protection (WAP), among others, have stepped up their pressure campaigns aimed at online travel agencies such as Expedia and Booking.com in order to persuade them to stop selling tickets to accredited zoos, aquariums, and marine parks. While wrapping themselves in the rhetoric of “animal welfare” and “animal protection,” these groups disseminate false and injurious allegations against accredited, world- renowned zoological facilities that provide extraordinary care for their animals and conduct substantial conservation work, public education, and scientific research that benefit animals in the wild. Meanwhile, the animal activist groups making the emotional, outdated and scientifically unsupportable claims, use little if any of their substantial resources to actually help animals in need themselves. Instead, they deploy millions to hire lawyers, lobbyists and public relations firms to attack and harm the reputations of some of the finest zoos and aquariums in the world, with the ultimate goal of ending the public display of all animals in human care.

While Alliance of Marine Mammal Parks & Aquariums (AMMPA) members strongly share the desire of our travel partners to ensure high animal welfare standards in tourism, the animal policy decisions made by travel companies have serious consequences for animals in human care, animals in the wild, and the zoos and aquariums that care for, study, and work to protect them. Animal tourism policies should be thoughtful, carefully researched, and based on peer- reviewed science, best practices in the zoological field, and the standards of recognized, expert accrediting and certifying bodies, not the unsubstantiated allegations and emotional appeals of animal rights activists. Otherwise, blanket policies that lump highly regarded, accredited zoological institutions in with substandard and inhumane operators stand to do more harm than good. As they consider changes to their animal tourism policies, travel companies should consult with knowledgeable experts from zoological accrediting bodies, as well as the independent scientists who conduct research in accredited facilities and in the wild, rather than relying solely on information and advice from animal activists who lack professional animal care experience, scientific credentials, or a record of peer-reviewed, published research relevant to the discussion.

“With our ocean in peril and wildlife facing what’s known as the Sixth Extinction, it is now more important than ever to find every viable way to connect people with animals for conservation purposes,” said Dr. Kristi West, a researcher at the Marine Mammal Stranding Lab at the University of Hawai’i Mānoa’s Institute of Marine Biology and a collaborator with the U.S. National Oceanic and Atmospheric Administration’s (NOAA) Marine Mammal Health and Stranding Response Program. “This includes accredited and humane-certified zoos, aquariums and marine parks that are leading efforts to save imperiled marine habitats and threatened animal species in the wild through public education, conservation, science and rescue efforts.”

Funding from government and NGO sources for conservation programs is woefully insufficient, making revenue from zoo and aquarium guest programs and visitation critically important. The unfortunate ramifications of animal rights activists’ continued efforts to bully online travel platforms to stop visits to leading zoos and aquariums will inevitably be a loss of funding for critical scientific studies, conservation and public education programs, advances in animal care, and the rescue and rehabilitation of sick and injured animals in the wild.

“The animal rights industry’s coordinated anti-zoo propaganda campaigns and attacks on the funding sources of the zoological community are actually harming the very animals activists claim they want to protect,” said Dr. Jason Bruck, a marine mammal scientist at Oklahoma State University. “Only through scientific study involving both animals under human care and animals in the wild will we be able to develop the conservation technologies and techniques of the 21st Century to help us protect these magnificent animals.”

Bruck said that the testing of new drones to study the health of wild dolphins and new methods of saving beached whales are just some of the tangible benefits modern zoos and aquariums are making possible through their support of scientific research.

“Independent scientists from all over the world rely on zoos and aquariums to collect meaningful data to both understand and save whales and dolphins, and this is a reality not widely understood by the public and often ignored by animal rights activists,” Bruck said. “If we lose these important institutions, we may very well lose some of our best tools in the fight to save endangered species.”

The animal rights industry’s assault on zoos and aquariums also could put thousands of animals at risk of homelessness if accredited zoological institutions are unable to continue to support the high cost of providing top quality animal care.

The inflammatory disinformation campaigns of animal rights activists are littered with stunningly false and unsubstantiated allegations. Here is a look at just a few of the false claims commonly featured in anti-zoo-and-aquarium narratives, along with the actual scientific information relevant to each issue.

(1)Scientific Research in Zoos and Aquariums

  1. Animal activist groups have incorrectly suggested that research in marine mammal facilities is of little importance for understanding cetaceans. This is blatantly false. In fact:
    • The vast majority of basic information about dolphins' perception, physiology, and cognition was discovered in research conducted at marine mammal facilities (e.g., echolocation and how it works,[1] diving physiology,[2] energetics,[3] gestation period,[4] hearing range,[5] signature whistles,[6] etc.).
    • Having close access to animals in human care allows scientists to study the animals and gather information that would otherwise be inaccessible. This basic information from studies in facilities directly informs scientists' interpretation of data from wild studies.
      • For example, once researchers understood that dolphin communication utilizes individually-specific signature whistles to maintain contact[7], they were then able to better understand thecommunication between dolphin mothers and calves during separations in the wild.[8]
  • See Scientist Statement supporting the importance of research in marine mammal facilities, signed by 82 scientists throughout the world. [Read Scientist Statement]
  1. Animal activist groups claim that research in marine mammal facilities does not benefit conservation in any way, suggesting that it is not relevant to wild animals or to conservation. This is false. Research in marine mammal facilities positively impacts conservation efforts for wild cetaceans in at least three ways:
    • Providing baseline information (e.g., typical respiration rates, metabolic rates, gestation length, hearing range and thresholds, etc.) necessary to inform conservation plans and practices.
      • For example, knowing a beluga whale’s hearing range and the frequency of newborn contact calls enables scientists and policymakers to understand that communication between beluga mothers and calves can be drowned out by boat noise.[9] This has direct conservation implications for how increased boat traffic can affect beluga mortality in the wild.[10]
    • Documenting cetaceans' physiological and behavioral responses to environmental stressors such as sound and contaminants, to further inform population managers.[11]
      • For example, swim trial studies combining movement tags and measurements of energy expenditure (i.e. respirometry) help scientists understand how entanglement and noise (e.g. sonar, oil and gas exploration, etc.) affect cetaceans.[12]
    • Developing and testing new techniques and tools for assessing cetacean health, which can then be used to assess wild and stranded animals.[13]
      • For example, noninvasive bio-logging tags used in hundreds of studies ranging from basic ecology to the effects of human disturbance are continuously improved in zoological facilities,[14] while novel methods are developed to sample DNA and hormones from exhalations,[15] improving health and genetics studies.

(2)Public Education in Zoos and Aquariums

  1. Animal rights activist groups incorrectly claim there is little objective evidence to suggest that keeping cetaceans in “captivity” is educational. This is false. Peer- reviewed scientific studies have shown that:
    • Experiencing live animals creates emotional connections.[16]
    • Such emotional connections increase conservation-mindedness.[17]
    • Experiences with live animals at zoos and aquariums positively impact visitors' conservation-related attitudes, knowledge, and behavior.[18]
      • To take just a single example, before the dolphin-safe label was conceived, millions of dolphins were dying in tuna net fisheries. During this time, a group of students from Colorado visited a dolphin facility in the Florida Keys, where they were introduced to dolphins and learned about the tuna issue. The students went back home, petitioned their entire school district, and got tuna banned from lunchrooms. StarKist tuna company lists this as one of the events that led to them to adopt dolphin-safe tuna practices and the label on their products.[19]
  2. Animal activist groups fail to recognize the educational value of experiencing animals in accredited zoological facilities, arguing that alternative experiences such as whale watching are better methods of educating and inspiring conservation. This is problematic on several levels:
    • To date, there have been no studies that have compared which of these methods are most effective for educating and inspiring conservation.
    • This is not an either/or situation.
      • Today, animal species are disappearing at an alarming rate due in large part to human impacts on the environment. We are in the middle of the Sixth Extinction.[20]
      • At the same time, children are becoming less and less connected to the very nature we need to protect.[21]
      • For conservation purposes, the importance of finding every way possible to connect people with animals cannot be overstated.
    • It is unwise and counter to the goal of conservation to suggest that everyone should or is able to view cetaceans in the wild.
      • Studies have shown that commercial whale watching often harms the wild whales that are being viewed, both through injuries and mortalities from collisions with the boats, as well as through causing behavioral changes that can impact biologically important behaviors such as feeding, resting, and reproduction.[22]
  • While responsible whale watching on a controlled scale is possible, significantly increasing whale-watching tourism would increase boat traffic, noise, pollution, and stress on the very populations we are attempting to conserve.[23]
  • Assuming that all or even most students, families and adults have the ability and means to travel to and participate in a whale-watching excursion is discriminatory and elitist.

(3)Survival and Life Expectancy of Animals in Human Care v. the Wild

The animal activist group, WAP, incorrectly claims that the survival rate of 97 percent for dolphins in facilities applies only to the U.S. Navy’s dolphins, who live very different lives than dolphins in marine parks. This is blatantly false.

  • The annual survival rate of 97.2 percent includes dolphins from all US facilities (including the U.S. Navy, marine parks, and other facilities).[24]
  • Decades ago, the survival rates of dolphins and killer whales in facilities were lower than in the wild.[25] However, survival rates have consistently and significantly increased over the years in marine mammal parks and aquariums.[26]
  • The most recent data show that:
    • The current survivorship of SeaWorld killer whales is not statistically different from that of any known wild killer whale population.[27]
    • Dolphins in zoos and aquariums today live as long or longer than dolphins in the wild.[24]

The group also incorrectly claims that the most current dolphin longevity research compared dolphins in facilities to only unhealthy wild populations. This is false.

  • In fact, one of the populations used in the most recent study[24] has been repeatedly used as the “healthy” comparison by NOAA in studies of wild populations.[28]

(4)Health of Animals in Human Care v. the Wild

Animal rights activist groups incorrectly suggest that cetaceans in zoological facilities contract more illnesses than cetaceans in the wild, due to chronic stress on the animals' immune systems. This is false. To the contrary:

  • There are no scientific studies suggesting that dolphins in marine mammal facilities are more prone to disease than dolphins in the wild. In fact:
    • Recent studies have shown that the immune systems of wild dolphins are much more challenged than the immune systems of dolphins in human care.[29]
  • There are no scientific studies suggesting that dolphins in marine mammal facilities are any more stressed than dolphins in the wild. In fact:
    • Studies have shown that cortisol levels (i.e., the "stress hormone") of dolphins in marine mammal facilities are either very similar to, or lower than, cortisol levels of wild dolphins, depending on the sampling technique.[30]

(5)Space of Animals in Human Care v. the Wild

Animal rights activists incorrectly claim that the space provided to cetaceans in marine mammal facilities is detrimental to the animals' welfare because it is significantly smaller than their home ranges in the wild. This is conjecture and is misleading.

  • In the wild, the lifestyle of dolphins and whales requires a large amount of space in order to search for diminishing food sources, find mates, and relocate when new threats are presented (often due to anthropogenic factors). Under human care, food sources and safety from predators are never a concern.
  • Therefore, as with all animals in human care situations (e.g., pets, domestic animals, etc.), the relevant animal welfare question is not whether marine mammal facilities exactly duplicate the wild, but rather whether they can meet the animals' needs, in terms of exercise and stimulation.
  • Of course, sufficient space to meet the animals' needs is required. However, there are no data suggesting that cetaceans in zoological settings need extraordinary amounts of physical space to achieve that end.
    • The positive reinforcement training sessions that are standard for cetaceans ensure that these animals get plenty of physical and mental exercise.[31]
  • For megafauna like dolphins, “optimal space may be best defined by qualitative rather than quantitative variables,” according to one of the foremost experts on animal welfare, Dr. Terry Maples.[32]
  • In other words, common features of cetacean zoological care such as cognitive and behavioral enrichment, and social stimulation, are more important to animal welfare than simply adding more space.[33]

(6)Can Cetaceans in Human Care Thrive?

The animal rights industry falsely claims that cetaceans cannot thrive in marine mammal facilities. This, again, is simply not true.

  • Today, cetaceans at high-quality, accredited facilities live long and healthy lives. They receive high-quality food, veterinary care, exercise, and behavioral enrichment,[32]and their survival rates,[24,27] health,[29] stress levels,[30] etc., are the same as or better than those of their counterparts in the wild. This is the evidence that is relevant to whether they can thrive in marine mammal facilities. They can, and they do.
  • However, not all marine mammal facilities worldwide are accredited and have high quality animal care. And, like any animal, cetaceans do not thrive in facilities with substandard care. Improving animal welfare worldwide will necessarily require, among other things, improving care at unaccredited, substandard facilities until they are able to become accredited, and addressing specific problems when they arise.

Conclusion

Thoughtful scrutiny of the claims made by the animal rights industry is crucial to ensure that policy decisions on animal tourism that could adversely affect animals in human care and in the wild, and the important work of hundreds of accredited zoos and aquariums, are based on peer-reviewed, scientific research rather than on the emotional appeals, anthropomorphism, and unsupported allegations of those who oppose animals in human care. We encourage companies evaluating their animal policies to read the supporting studies referenced in this document and to read the supporting studies animal rights activists reference, or note when such references are conspicuously absent.

We also encourage travel companies to consult directly with independent scientists currently working with cetaceans in accredited zoos, aquariums and marine parks, many of whom also do research with animals in the wild, for accurate information about the welfare of the animals in zoological facilities based on their own hands-on experience and to hear from them about the essential contributions their research is making to the welfare of both animals in human care and animals in the wild.

Finally, we encourage travel companies to reject the many misguided new sets of “standards” and inspection schemes being proposed by animal rights activist groups, as they are not based on best zoological practices or informed by peer- reviewed science or the opinions of experts with experience caring for or studying animals in zoological facilities. Instead, we urge travel companies to embrace the well- established standards of recognized accrediting and certifying bodies such as AMMPA, American Humane, and the Association of Zoos and Aquariums and to promote tourism to zoos, aquariums, and marine parks that have worked hard to meet those standards and earn their accreditation or certification.

We share our travel partners’ desire to promote animal welfare in tourism and are happy to provide additional information, resources, and references. Inquiries may be directed to news@ammpa.org.

The Alliance of Marine Mammal Parks & Aquariums is the leading trade association and accrediting body for zoos, aquariums, and marine parks throughout the world that exhibit marine mammals. The Alliance supports the highest standards of care for marine mammals and contributes to their conservation in the wild through public education, scientific research, and the rescue and rehabilitation of sick and injured animals in the wild. Our accredited institutions in the U.S., Canada, Mexico, Europe, Asia, and the Caribbean collectively possess the largest body of marine mammal experience and expertise in the world.

REFERENCES

  1. e.g., Kellogg, W. N. (1958). Echo ranging in the porpoise. Science, 128, 982-988.

Norris, K. S., Prescott, J. H., Asa-Dorian, P. V., & Perkins, P. (1961). An experimental demonstration of echolocation behavior in the porpoise, Tursiops truncatus (Montague). Biological Bulletin, 120, 163-176.

Au, W. W. L. (1993). The sonar of dolphins. New York: Springer-Verlag.

  1. e.g., Ridgway, S. H., & Howard, R. (1979). Dolphin lung collapse and intramuscular circulation during free diving: evidence from nitrogen washout. Science, 206(4423), 1182-1183.

Skrovan, R. C., Williams, T. M., Berry, P. S., Moore, P. W., & Davis, R. W. (1999). The diving physiology of bottlenose dolphins (Tursiops truncatus). II. Biomechanics and changes in buoyancy at depth. Journal of Experimental Biology, 202(20), 2749-2761.

Noren, S. R., Cuccurullo, V., & Williams, T. M. (2004). The development of diving bradycardia in bottlenose dolphins (Tursiops truncatus). Journal of Comparative Physiology B, 174, 139-147.

  1. e.g., Williams, T. M., Friedl, W. A., & Haun, J. E. (1993). The physiology of bottlenose dolphins (Tursiops truncatus): Heart rate, metabolic rate and plasma lactate concentration during exercise. Journal of Experimental Biology, 179, 31-46.

Holt, M. M., Noren, D. P., Dunkin, R. C., & Williams, T. M. (2015). Vocal performance affects metabolic rate in dolphins: Implications for animals communicating in noisy environments. The Journal of Experimental Biology, 218, 1647-1654.

  1. e.g., Essapian, F. S. (1963). Observations on abnormalities of parturition in captive bottle- nosed dolphins, Tursiops truncatus, and concurrent behavior of other porpoises. Journal of Mammalogy, 44, 405-414.

Cornell, L. H., Asper, E. D., Antrim, J. E., Searles, S. S., Young, W. G., & Goff, T. (1987). Progress report: Results of a long-range captive breeding program for the bottlenose dolphin, Tursiops truncatus and Tursiops truncatus gilli. Zoo Biology, 6, 41-53.

Duffield, D. A., Odell, D. K., McBain, J. F., & Andrews, B. (1995). Killer whale (Orcinus orca) reproduction at Sea World. Zoo Biology, 14, 417-430.

  1. e.g., Hall, J. D., & Johnson, C. S. (1972). Auditory thresholds of a killer whale Orcinus orca Linnaeus. The Journal of the Acoustical Society of America, 51(2B), 515-517.

Kellogg, W. N. (1953). Ultrasonic hearing in the porpoise, Tursiops truncatus. Journal of comparative and physiological psychology, 46, 446-450.

  1. e.g., Caldwell, M. C., & Caldwell, D. K. (1965). Individualized whistle contours in bottle-nosed dolphins (Tursiops truncatus). Nature, 207, 434-435.

Tyack, P. L. (1986). Whistle repertoires of two bottlenosed dolphins, Tursiops truncatus: Mimicry of signature whistles? Behavioral Ecology and Sociobiology, 18, 251-257.

Janik, V. M., & Slater, P. J. B. (1998). Context-specific use suggests that bottlenose dolphin signature whistles are cohesion calls. Animal Behaviour, 56, 829-838.

  1. e.g., Caldwell, M. C., & Caldwell, D. K. (1965). Individualized whistle contours in bottle-nosed dolphins (Tursiops truncatus). Nature, 207, 434-435.

Caldwell, M. C., & Caldwell, D. K. (1968). Vocalization of naïve captive dolphins in small groups. Science, 159, 1121-1123.

  1. Smolker, R. A., Mann, J., & Smuts, B. B. (1993). Use of signature whistles during separations and reunions by wild bottlenose dolphin mothers and infants. Behavioral Ecology and Sociobiology, 33, 393-402.
  2. Vergara, V., Michaud, R., & Barrett-Lennard, L. (2010). What can captive whales tell us about their wild counterparts? Identification, usage, and ontogeny of contact calls in belugas (Delphinapterus leucas). International Journal of Comparative Psychology, 23, 278-309.

[10] e.g., http://digitaledition.chicagotribune.com/tribune/article_popover.aspx?guid=c849eedb-1743- 4c01-875d-44c6739dcb7f

  1. See review in Houser, D. S., Finneran, J. J., & Ridgway, S. H. (2010). Research with Navy marine mammals benefits animal care, conservation, and biology. International Journal of Comparative Psychology, 23, 249-268.
  2. e.g., van der Hoop, J. M., Fahlman, A., Hurst, T., Rocho-Levine, J., Shorter, K. A., Petrov, V., & Moore, M. J. (2014). Bottlenose dolphins modify behavior to reduce metabolic effect of tag attachment. Journal of Experimental Biology, 217(23), 4229-4236.

Williams, T. M., Kendall, T. L., Richter, B. P., Ribeiro-French, C. R., John, J. S., Odell, K. L., ... & Stamper, M. A. (2017). Swimming and diving energetics in dolphins: a stroke-by-stroke analysis for predicting the cost of flight responses in wild odontocetes. Journal of Experimental Biology, 220(6), 1135-1145.

  1. e.g., Dennison, S., Moore, M. J., Fahlman, A., Moore, K., Sharp, S., Harry, C. T., ... & Wells,

R. S. (2012). Bubbles in live-stranded dolphins. Proceedings of the Royal Society B, 279, 1396- 1404.

Fair, P. A., Schaefer, A. M., Houser, D. S., Bossart, G. D., Romano, T. A., Champagne, C. D., ... & Reif, J. S. (2017). The environment as a driver of immune and endocrine responses in dolphins (Tursiops truncatus). PLoS ONE, 12(5), e0176202.

Mann, D., Hill-Cook, M., Manire, C., Greenhow, D., Montie, E., Powell, J., ... & DiGiovanni Jr, R. (2010). Hearing loss in stranded odontocete dolphins and whales. PLoS ONE, 5(11), e13824.

Ruiz, C. L., Nollens, H. H., Venn-Watson, S., Green, L. G., Wells, R. S., Walsh, M. T., ... & Jacobson, E. R. (2009). Baseline circulating immunoglobulin G levels in managed collection and free-ranging bottlenose dolphins (Tursiops truncatus). Developmental & Comparative Immunology, 33(4), 449-455.

Schwacke, L. H., Smith, C. R., Townsend, F. I., Wells, R. S., Hart, L. B., Balmer, B. C., ... & Lamb, S.

V. (2013). Health of common bottlenose dolphins (Tursiops truncatus) in Barataria Bay, Louisiana, following the Deepwater Horizon oil spill. Environmental Science & Technology, 48, 93-103.

  1. e.g., Gabaldon, J., Turner, E. L., Johnson-Roberson, M., Barton, K., Johnson, M., Anderson,

E. J., & Shorter, K. A. (2019). Integration, Calibration, and Experimental Verification of a Speed Sensor for Swimming Animals. IEEE Sensors Journal, 19(10), 3616-3625.

Pearson, H. C., Jones, P. W., Srinivasan, M., Lundquist, D., Pearson, C. J., Stockin, K. A., & Machovsky-Capuska, G. E. (2017). Testing and deployment of C-VISS (cetacean-borne video camera and integrated sensor system) on wild dolphins. Marine biology, 164(3), 42.

Johnson, M., Tyack, P., Gillespie, D., & McConnell, B. (2014). A multi-week behavioral sampling tag for sound effects studies: Design trade-offs and prototype evaluation. SAINT ANDREWS UNIV (UNITED KINGDOM).

Johnson, M., & Tyack, P. (2005). Development and Field testing of the DTAG for Deep-Diving Odontocetes (No. WHOI-130705SP). WOODS HOLE OCEANOGRAPHIC INSTITUTION MA.

 [15] Frère, C. H., Krzyszczyk, E., Patterson, E. M., Hunter, S., Ginsburg, A., & Mann, J. (2010). Thar she blows! A novel method for DNA collection from cetacean blow. PloS one, 5(8), e12299.

Richard, J. T., Robeck, T. R., Osborn, S. D., Naples, L., McDermott, A., LaForge, R., ... & Sartini, B.L. (2017). Testosterone and progesterone concentrations in blow samples are biologically relevant in belugas (Delphinapterus leucas). General and comparative endocrinology, 246, 183- 193.

  1. e.g., Myers, O. E,. Saunders, C. D., & Birjulin, A. A. (2004). Emotional dimensions of watching zoo animals: An experience sampling study building on insights from psychology. Curator, 47, 299–321.

Bruni, C., Fraser, J., & Schultz, P. (2008). The value of zoo experiences for connecting people with nature. Visitor Studies, 11, 139–150.

Clayton, S., Fraser, J., & Saunders, C. D. (2009). Zoo experiences: Conversations, connections, and concern for animals. Zoo Biology, 28, 377–397.

  1. e.g., Skibins, J. C., & Powell, R. B. (2013). Conservation caring: Measuring the influence of zoo visitors' connection to wildlife on pro-conservation behaviors. Zoo Biology, 32, 528–540.

Powell, D. M., & Bullock, E. V. (2014). Evaluation of factors affecting emotional responses in zoo visitors and the impact of emotion on conservation mindedness. Anthrozoös, 27, 389–405.

  1. Miller, L. J., Zeigler-Hill, V., Mellen, J., Koeppel, J., Greer, T., & Kuczaj, S. (2013). Dolphin shows and interaction programs: Benefits for conservation education? Zoo Biology, 32, 45–53.

Skibins, J. C., & Powell, R. B. (2013). Conservation caring: Measuring the influence of zoo visitors' connection to wildlife on pro-conservation behaviors. Zoo Biology, 32, 528–540.

Moss, A., Jensen, E., & Gusset, M. (2014). Evaluating the contribution of zoos and aquariums to Aichi Biodiversity Target 1. Conservation Biology, 29, 537–544.

  1. http://www.nytimes.com/1990/04/18/garden/how-youths-rallied-to-dolphins-cause.html
  2. Ceballos, G., Ehrlich, P. R., Barnosky, A. D., García, A., Pringle, R. M., & Palmer, T. M. (2015). Accelerated modern human–induced species losses: Entering the sixth mass extinction. Science Advances, 1(5), e1400253.
  3. Louv, R. (2008). Last child in the woods: Saving our children from nature-deficit disorder. Algonquin Books.
  4. See review in Parsons, E. C. M. (2012). The negative impacts of whale-watching. Journal of Marine Biology, Article ID 807294. doi:10.1155/2012/807294.
  5. e.g., de Vere, A. J., Lilley, M. K., & Frick, E. E. (2018). Anthropogenic impacts on the welfare of wild marine mammals. Aquatic Mammals, 44(2), 150-180.
  6. Jaakkola, K., & Willis, K. (2019). How long do dolphins live? Survival rates and life expectancies for bottlenose dolphins in zoological facilities vs. wild populations. Marine Mammal Science, 35, 1418–1437.

https://youtu.be/YMViAQMvrJY

  1. DeMaster, D. P., & Drevenak, J. K. (1988). Survivorship patterns in three species of captive cetaceans. Marine Mammal Science, 4, 297-311.

Duffield, D. A., & Wells, R. S. (1991). Bottlenose dolphins: Comparison of census data from dolphins in captivity with a wild population. Soundings, 16(2), 11-15.

Small, J., & Demaster, D. P. (1995). Survival of five species of captive marine mammals. Marine Mammal Science, 11, 209 - 226.

  1. Small, J., & Demaster, D. P. (1995). Survival of five species of captive marine mammals. Marine Mammal Science, 11, 209 - 226.

Innes, W.S. (2005). Survival rates of marine mammals in captivity: Temporal trends and institutional analysis. MS Thesis, Duke University.

Jett, J., & Ventre, J. (2015). Captive killer whale (Orcinus orca) survival. Marine Mammal Science, 31, 1362-1377.

Robeck, T. R., Willis, K., Scarpuzzi, M. R., & O’Brien, J. K. (2015). Comparisons of life-history parameters between free-ranging and captive killer whale (Orcinus orca) populations for application toward species management. Journal of Mammalogy, 96,1055-1070.

Jaakkola, K., & Willis, K. (2019). How long do dolphins live? Survival rates and life expectancies for bottlenose dolphins in zoological facilities vs. wild populations. Marine Mammal Science, 35, 1418–1437.

  1. Robeck, T. R., Willis, K., Scarpuzzi, M. R., & O’Brien, J. K. (2015). Comparisons of life-history parameters between free-ranging and captive killer whale (Orcinus orca) populations for application toward species management. Journal of Mammalogy, 96,1055-1070.
  2. e.g., Balmer, J. E., Ylitalo, G. M., Rowles, T. K., Mullin, K. D., Wells, R. S., Townsend, F. I., Pearce, R. W., Bolton, J. L., Zolman, E. S., Balmer, B. C., & Schwacke, L. H. (2018). Persistent organic pollutants (POPs) in blood and blubber of common bottlenose dolphins (Tursiops truncatus) at three northern Gulf of Mexico sites following the Deepwater Horizon oil spill. Science of the Total Environment, 621, 130-137.

Schwacke, L. H., Twiner, M. J., De Guise, S., Balmer, B. C., Wells, R. S., Townsend, F. I., Rotstein,

D. C., Varela, R. A., Hansen, L. J., Zolman, E. S. & Spradlin, T. R. (2010). Eosinophilia and biotoxin exposure in bottlenose dolphins (Tursiops truncatus) from a coastal area impacted by repeated mortality events. Environmental Research, 110(6), 548-555.

Schwacke, L. H., Zolman, E. S., Balmer, B. C., De Guise, S., George, R. C., Hoguet, J., Hohn, A. A., Kucklick, J. R., Lamb, S., Levin, M., & Litz, J. A. (2011). Anaemia, hypothyroidism and immune suppression associated with polychlorinated biphenyl exposure in bottlenose dolphins (Tursiops truncatus). Proceedings of the Royal Society B: Biological Sciences, 279(1726), 48-57.

Smith, C. R., Rowles, T. K., Hart, L. B., Townsend, F. I., Wells, R. S., Zolman, E. S., Balmer, B. C., Quigley, B., Ivančić, M., McKercher, W., & Tumlin, M. C. (2017). Slow recovery of Barataria Bay dolphin health following the Deepwater Horizon oil spill (2013-2014), with evidence of persistent lung disease and impaired stress response. Endangered Species Research, 33, 127- 142.

  1. Fair, P. A., Schaefer, A. M., Houser, D. S., Bossart, G. D., Romano, T. A., Champagne, C. D., ... & Reif, J. S. (2017). The environment as a driver of immune and endocrine responses in dolphins (Tursiops truncatus). PLoS ONE, 12(5), e0176202.

Ruiz, C. L., Nollens, H. H., Venn-Watson, S., Green, L. G., Wells, R. S., Walsh, M. T., ... & Jacobson, E. R. (2009). Baseline circulating immunoglobulin G levels in managed collection and free-ranging bottlenose dolphins (Tursiops truncatus). Developmental & Comparative Immunology, 33(4), 449-455.

  1. See review in Proie, S. (2013). A systematic review of cortisol levels in wild and captive Atlantic bottlenose dolphin (Tursiops truncatus), killer whale, (Orcinus orca), and beluga whale (Delphinapterus leucas). MA Thesis, Evergreen State College.
  2. e.g., Brando, S. I. (2010). Advances in husbandry training in marine mammal care programs.

International Journal of Comparative Psychology, 23(4), 777-791.

  1. Maple, T. L., & Perdue, B. M. (2013). Zoo animal welfare. Heidelberg: Springer. (p. 78)
  2. Yamanishi, Y., & Hayashi, M. (2011). Assessing cognitive experiments on the welfare of captive chimpanzees by direct comparison of activity budgets between wild and captive chimpanzees. American Journal of Primatology, 73, 1231-1238.

Shepherdson, D., Lewis, K. D., Carlstead, K., Bauman, J., & Perrin, N. (2013). Individual and environmental factors associated with stereotypic behavior and fecal glucocorticoid metabolite levels in zoo housed polar bears. Applied Animal Behaviour Science, 147, 268-277.

Maple, T. L., & Perdue, B. M. (2013). Zoo animal welfare. Heidelberg: Springer.