Towards understanding the welfare of cetaceans in accredited zoos and aquariums

Health and Welfare Benefits of Computerized Cognitive Enrichment in California Sea Lions (Zalophus californianus) at the US Navy Marine Mammal Program

Cognitive enrichment is becoming more prevalent in professional marine mammal facilities. Research with dolphins has suggested that such enrichment provides more welfare benefits than enrichment that does not incorporate cognitive challenge. However, there is little research supporting the use of cognitive enrichment as a means to improve the welfare of sea lions. Recently, a novel form of technological cognitive enrichment, the Enclosure Video Enrichment (EVE) system, was introduced to a population of California sea lions at the US Navy's Marine Mammal Program as a means to enhance welfare. Two of the initial focal animals introduced to EVE were selected based on their health history and the possible benefits of cognitive enrichment in improving health measures. To evaluate this, information regarding the animals' consumption of their offered diet was compared to other animals in the population of similar age and the absence of a similar health history. Subsequently, the total diet consumption of the targeted animals was evaluated in the two years prior to the introduction to EVE and compared to the total diet consumption during the initial 2 years of regular EVE sessions. There was a significant decrease in the number of days in which the sea lions did not consume their entire offered diet in the two years after implementing regular EVE sessions, an increase in participation and performance of voluntary husbandry behaviors, and a reduction in the number of days animals were clinically ill. This study provides evidence of cognitive enrichment as a management tool to improve animal health and welfare as well as performance in training sessions.

Using Anticipatory Behavior to Detect the Change in Interest in an Activity Repeated Several Times and Avoid Habituation in Bottlenose Dolphins (Tursiops Truncatus)

Environmental enrichment is an essential component of the management policies used by zoos and aquaria to promote animals' welfare. However, when enrichments are provided several times, they can cause habituation and lose their enrichment effects. A simple method to avoid it could be making a preventive assessment about the trend of animals' interest in a stimulus provided several times. Here, we hypothesized that anticipatory behavior could be used to assess the decrease in interest in playing with objects when the activity is repeated. Moreover, we also assumed that this could be done before providing objects to play with. Our results support this hypothesis. Specifically, we found a positive correlation between the time the 7 dolphins tested spent performing anticipatory behavior before the enrichment sessions and the time they spent playing with objects during those sessions. As a result, anticipatory behavior performed before enrichment sessions predicted dolphins' interest in the session and allowed us to assess whether the sessions had lost their enrichment effect.

Dolphin-WET-Development of a Welfare Evaluation Tool for Bottlenose Dolphins (Tursiops truncatus) under Human Care

Ensuring high standards of animal welfare is not only an ethical duty for zoos and aquariums, but it is also essential to achieve their conservation, education, and research goals. While for some species, animal welfare assessment frameworks are already in place, little has been done for marine animals under human care. Responding to this demand, the welfare committee of the European Association for Aquatic Mammals (EAAM) set up a group of experts on welfare science, cetacean biology, and zoo animal medicine across Europe. Their objective was to develop a comprehensive tool to evaluate the welfare of bottlenose dolphins (Tursiops truncatus), named Dolphin-WET. The tool encompasses 49 indicators that were either validated through peer review or management-based expertise. The first of its kind, the Dolphin-WET is a species-specific welfare assessment tool that provides a holistic approach to evaluating dolphin welfare. Inspired by Mellor's Five Domains Model and the Welfare Quality®, its hierarchical structure allows for detailed assessments from overall welfare down to specific indicators. Through combining 37 animal-based and 12 resource-based indicators that are evaluated based on a two- or three-level scoring, the protocol offers a detailed evaluation of individual dolphins. This approach allows for regular internal monitoring and targeted welfare management, enabling caretakers to address specific welfare concerns effectively.

The Cetacean Sanctuary: A Sea of Unknowns

Housing cetaceans in netted sea pens is not new and is common for many accredited managed-care facilities. Hence, the distinction between sanctuary and sea pen is more about the philosophies of those who run these sanctuary facilities, the effects of these philosophies on the animals' welfare, and how proponents of these sanctuaries fund the care of these animals. Here, I consider what plans exist for cetacean sanctuaries and discuss the caveats and challenges associated with this form of activist-managed captivity. One goal for stakeholders should be to disregard the emotional connotations of the word "sanctuary" and explore these proposals objectively with the best interest of the animals in mind. Another focus should be related to gauging the public's understanding of proposed welfare benefits to determine if long-term supporters of donation-based sanctuary models will likely see their expectations met as NGOs and their government partners consider moving forward with cetacean sanctuary experiments.

Survival improvements of marine mammals in zoological institutions mirror historical advances in human longevity

An intense public debate has fuelled governmental bans on marine mammals held in zoological institutions. The debate rests on the assumption that survival in zoological institutions has been and remains lower than in the wild, albeit the scientific evidence in support of this notion is equivocal. Here, we used statistical methods previously applied to assess historical improvements in human lifespan and data on 8864 individuals of four marine mammal species (harbour seal, Phoca vitulina; California sea lion, Zalophus californianus; polar bear, Ursus maritimus; common bottlenose dolphin, Tursiops truncatus) held in zoos from 1829 to 2020. We found that life expectancy increased up to 3.40 times, and first-year mortality declined up to 31%, during the last century in zoos. Moreover, the life expectancy of animals in zoos is currently 1.65-3.55 times longer than their wild counterparts. Like humans, these improvements have occurred concurrently with advances in management practices, crucial for population welfare. Science-based decisions will help effective legislative changes and ensure better implementation of animal care.

Are Dolphins Kept in Impoverished Environments?

Numerous studies have demonstrated the negative effects of impoverished environments versus the positive effects of enriched environments on animals' cognitive and neural functioning. Recently, a hypothesis was raised suggesting that conditions for dolphins in zoological facilities may be inherently impoverished, and thus lead to neural and cognitive deficits. This review directly examines that hypothesis in light of the existing scientific literature relevant to dolphin welfare in zoological facilities. Specifically, it examines how dolphins are housed in modern zoological facilities, where the characteristics of such housing fall on the continuum of impoverished-to-enriched environments, and the extent to which dolphins show behavioral evidence characteristic of living in impoverished environments. The results of this analysis show that contrary to the original hypothesis, modern zoological facilities do not inherently, or even typically, house dolphins in impoverished conditions. However, it also notes that there is variation in animal welfare across different zoological facilities, and that "not impoverished" would be a particularly low bar to set as an animal welfare standard. To optimize cognitive well-being, strategies for providing additional cognitive challenges for dolphins in zoological facilities are suggested.

Integrating Reference Intervals into Chimpanzee Welfare Research

Animal welfare researchers are committed to developing novel approaches to enhance the quality of life of chimpanzees living in professional care. To systematically monitor physical, mental, and emotional states, welfare scientists highlight the importance of integrating non-invasive, animal-based welfare indicators. This study aimed to create species-specific reference intervals for behavioral measures and physiological biomarkers. Specifically, we analyzed data from 40 adult chimpanzees (22 females, 18 males) residing at 16 zoological facilities to generate reference intervals for behavioral states and events, behavioral diversity, fecal glucocorticoid metabolites (GCMs), and fecal immunoglobulin-A (IgA). Comparisons of sex and age using linear regression models revealed significant differences for several behaviors. The proportion of time spent engaged in mutual/multiple social grooming significantly decreased as individuals aged. Furthermore, males spent a higher proportion of time performing aggressive contact behaviors and displaying to other chimpanzees when compared to females. Males also performed sexual examination behaviors at a higher rate than females. Behavioral diversity, fecal GCM, and fecal IgA did not vary by sex or age. In the future, values for individual chimpanzees can be compared to the ranges reported here for particular age/sex classes. Ultimately, animal care professionals can utilize reference intervals to make evidence-based decisions regarding management practices and environmental conditions.

Quantifying the 60-Year Contribution of Japanese Zoos and Aquariums to Peer-Reviewed Scientific Research

Simple Summary

Today’s zoos and aquariums claim to be shifting from being entertainment facilities to centers for the conservation of biodiversity. To make this shift, scientific research, including understanding the biology of endangered species and improving the environment of captive animals, is essential. Several studies have examined the trends in the number of research papers published by zoos and aquariums globally and indicated that this number has increased over the past few decades. In this study, we examined the trends in the number of papers published by Japanese zoos and aquariums over the past 62 years to determine whether research activities are also developing in Japan. We found that the number of research papers has significantly increased and that the research fields have diversified since around 1990. However, we also found some problems: about a quarter of the institutions have published no papers, research targets in zoos were biased toward captive mammals and that aquariums conducted little research on animal welfare. Addressing these issues, we would argue, will help Japanese zoos and aquariums to make further progress.

Abstract

With the shift in their social roles, modern zoos and aquariums are required to develop scientific research. Although zoos and aquariums worldwide have reported an increase in the number of papers they publish and the diversification of their fields in recent decades, the specific circumstances in Japan are slightly unclear. We listed peer-reviewed papers authored by Japanese zoos and aquariums using search engines and quantitatively evaluated the changes in the number of papers published over 62 years. Our results showed that papers published in Japan have increased remarkably since the 1990s, and research fields have diversified as in the rest of the world. In particular, joint research with research institutes has seen an upward trend, and the instances of English-language papers have increased. Meanwhile, the content of the research was biased. In zoos, research on animal welfare has been increasing, but the focus was heavily biased toward captive mammals. Aquariums contributed to the understanding of local ecosystems through the fundamental study of wildlife, but there were fewer papers on improving husbandry. Our results indicated that while research by Japanese zoos and aquariums is developing, research on welfare, conservation, and education regarding native endangered species must still be improved.