Refinement Database

Database on Refinement of Housing, Husbandry, Care, and Use of Animals in Research

This database, created in 2000, is updated every four months with newly published scientific articles, books, and other publications related to improving or safeguarding the welfare of animals used in research.

Tips for using the database:

  • This landing page displays all of the publications in the database.
  • Use the drop-down menus to filter these publications by Animal Type, Setting, and/or Topic.
  • Clicking on a parent category (e.g., Rodent) will include publications relating to all the items in that category (e.g., Chinchilla, Gerbil, Guinea Pig, etc.).
  • You may also add a keyword to further narrow your search.
  • Please note that at this time, only publications dated 2010 or later (with some exceptions) can be filtered by Animal Type and Topic, and only publications dated 2020 or later (with some exceptions) can be filtered by Setting. Most publications older than 2010 can only be searched by keyword. 
Skovlund, C. R., Kirchner, M. K., Moos, L. W. et al. 2021. A critical review of animal-based welfare indicators for polar bears (Ursus maritimus) in zoos: Identification and evidence of validity. Animal Welfare 30(1), 1-18.

Captive polar bears (Ursus maritimus) are well-documented as being prone to behavioural disorders and, as a result, their welfare is the cause of increasing concern. There is therefore a need for an evidence-based approach to...

Fernandez, E. J. 2021. Appetitive search behaviors and stereotypies in polar bears (Ursus maritimus). Behavioural Processes 182, 104299.

Stereotypies in captive animals have been defined as repetitive, largely invariant patterns of behavior that serve no obvious goal or function. Stereotypies are commonly attributed to boredom or stress and are typically treated by enriching...

Whitmer, E. R., Trumbull, E. J., Harris, H. S. et al. 2021. Use of potassium chloride for low-residue euthanasia of anesthetized California sea lions (Zalophus californianus) and northern elephant seals (Mirounga angustirostris) with life-threatening injury or disease. Journal of the AVMA 259(2), 197-201.

BACKGROUND: The need for field euthanasia of pinnipeds occasionally arises for circumstances in which carcass retrieval for disposal is logistically challenging to impossible. This could include mass stranding events, remote field research, or carcasses that...

Vonk, J., McGuire, M. C., Johnson-Ulrich, Z. 2021. Bearing fruit: Piloting a novel judgment bias task in an American black bear. Zoo Biology 40(2), 89-97.

Judgment bias tasks can reveal changes in affect in animals as a function of environmental manipulations such as provision of enrichment. We assessed affect in an American black bear across seasonal changes in availability of...

Emmett, C., Digby, M., Pope, J. et al. 2021. Social behaviour in zoo bachelor groups: A case study of related South American fur seals. Animals 11(9), 2682.

Appropriate management of social groups is one of the greatest challenges that face zoos and aquaria worldwide. To facilitate breeding programmes, particularly in polygynous species, there is a need to house surplus males in bachelor...

Maher, C. J., Gibson, A., Dixon, L. M. et al. 2021. Developing a reliable welfare assessment tool for captive hibernatory bear species. Animals 11(11), 3090.

Animal welfare assessments are essential for the identification of welfare hazards and benchmarking of welfare improvements, though welfare assessments for zoo species are lacking. Bears are commonly housed in zoos but currently no composite welfare...

Zemanova, M. A. 2021. Noninvasive genetic assessment is an effective wildlife research tool when compared with other approaches. Genes 12(11), 1672.

Wildlife research has been indispensable for increasing our insight into ecosystem functioning as well as for designing effective conservation measures under the currently high rates of biodiversity loss. Genetic and genomic analyses might be able...

Bernstein-Kurtycz, L. M., Koester, D. C., Snyder, R. J. et al. 2021. “Bearly” changing with the seasons: Bears of five species show few behavioral changes across seasons and at varying visitor densities. Animal Behavior and Cognition 8(4), 538–557.

In natural environments, bear behavior follows seasonal patterns but the zoo environment differs from the natural environment in several ways, including the presence of zoo visitors. Although typically difficult to disentangle, we were able to...

Fuller, G., Hamilton, J., Allard, S. 2021. DNA damage as a potential non-invasive indicator of welfare: A preliminary study in zoo-housed grizzly bears (Ursus arctos horribilis). Journal of Zoological and Botanical Gardens 2(3), 316–334.

Measures of oxidative stress have potential for integrating positive and negative life experiences into comprehensive cellular indicators of animal welfare. We explored this possibility when three adult grizzly bear brothers at the Detroit Zoo were...

Melfi, V. A., Dorey, N. R., Ward, S. (Eds.) 2020. Zoo Animal Learning and Training. John Wiley & Sons: Hoboken, NJ, 384 pp.

Comprehensively explains animal learning theories and current best practices in animal training within zoos. This accessible, up-to-date book on animal training in a zoo/aquaria context provides a unified approach to zoo animal learning, bringing together...

Harvey, A., Beausoleil, N., Ramp, D. et al. 2020. A ten-stage protocol for assessing the welfare of individual non-captive wild animals: Free-roaming horses (Equus ferus caballus) as an example. Animals 10(1), 148.

Knowledge of the welfare status of wild animals is vital for informing debates about the ways in which we interact with wild animals and their habitats. Currently, there is no published information about how to...

Zemanova, M. A. 2020. Towards more compassionate wildlife research through the 3Rs principles: Moving from invasive to noninvasive methods. Wildlife Biology 2020(1), no page numbers.

Research in ecology and wildlife biology remains crucial for increasing our knowledge and improving species management and conservation in the midst of the current biodiversity crisis. However, obtaining information on population status often involves invasive...

Hammond, C. 2020. Comparing the frequency of stereotypical and non-stereotypical behaviours in captive brown bears (Ursus arctos arctos) at The Wildwood Trust. RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 47(1), 4-7.

Zoos play an important role in conservation, participating in captive breeding programmes and scientific research. The research can be shared and inform practice in the field and zoos. A behavioural observation study was conducted on...

Miller, L. J., Vicino, G. A., Sheftel, J. et al. 2020. Behavioral diversity as a potential indicator of positive animal welfare. Animals 10(7), 1211.

Modern day zoos and aquariums continuously assess the welfare of their animals and use evidence to make informed management decisions. Historically, many of the indicators of animal welfare used to assess the collection are negative...

Fernandez, E. J., Yoakum, E., Andrews, N. 2020. Seasonal and daily activity of two zoo-housed grizzly bears (Ursus arctos horribilis). Journal of Zoological and Botanical Gardens 1(1), 1–12.

Captive grizzly bears, like their wild counterparts, engage in considerable variability in their seasonal and daily activity. We documented the year-long activity of two grizzly bears located at the Woodland Park Zoo in Seattle, Washington...

Vaicekauskaite, R., Schneider, J. N., Delfour, F. 2019. Does enrichment improve well being in animals under human care? A case study of two harbor seals (Phoca vitulina). Journal of Applied Animal Welfare Science 22(3), 255-266.

Harbor seals in the wild live in a stimulating environment; therefore, nonhuman-animal caretakers have increasingly been using environmental enrichment to improve the well being of seals under human care. The purpose of this study was...

Sherwen, S. L., Hemsworth, P. H. The visitor effect on zoo animals: Implications and opportunities for zoo animal welfare. Animals 9(6), 366.

Achieving and maintaining high standards of animal welfare is critical to the success of a modern zoo. Research has shown that an animal's welfare is highly dependent on how various individual animal factors (e.g., species...

Chudeau, K. R., Johnson, S. P., Caine, N. G. 2019. Enrichment reduces stereotypical behaviors and improves foraging development in rehabilitating Eastern Pacific Harbor Seals (Phoca vitulina richardii). Applied Animal Behaviour Science 219, 104830.

There is empirical support for the efficacy of enrichment in decreasing stereotypical behaviors and increasing naturalistic behaviors in laboratory, agricultural, and zoological settings. However, little research has been done on the possible value of enrichment...

Egelkamp, C. L., Ross, S. R. 2019. A review of zoo-based cognitive research using touchscreen interfaces. Zoo Biology 38(2), 220-235.

In the past few decades, there has been an increase in the number of zoo-based touchscreen studies of animal cognition around the world. Such studies have contributed to the field of comparative cognition despite the...

Soriano, A. I., Vinyoles, D., Maté, C. 2019. Patterns of animal–enrichment interaction in captive brown bears. Zoo Biology 38(3), 239-247.

We studied the behavioral responses of three brown bears (Ursus arctos) to different types of enrichment devices to assess the predominant pattern of animal-enrichment interaction (PAI) to each type of enrichment. We assessed the bears'...

Van Horn, R. C., Sutherland-Smith, M., Bracho Sarcos, A. E. et al. 2019. The Andean bear alopecia syndrome may be caused by social housing. Zoo Biology 38(5), 434-441.

The Andean bear alopecia syndrome is a progressive and chronic condition documented in ex situ populations. Recent advances focus on treating symptoms, not preventing future cases. We therefore explored the epidemiology of this syndrome through...

Cox, R. J., Nol, P., Ellis, C. K. et al. 2019. Research with agricultural animals and wildlife. ILAR Journal 60(1), 66-73.

In fiscal year 2016, agricultural animals such as swine, sheep, goats, and cattle represented 10% of the 820 812 animals used in USDA-regulated research. In addition to traditional agricultural animals, research studies using captive wildlife...

Fischer, C. P., Romero, L. M. 2019. Chronic captivity stress in wild animals is highly species-specific. Conservation Physiology 7(1), coz093.

Wild animals are brought into captivity for many reasons—conservation, research, agriculture and the exotic pet trade. While the physical needs of animals are met in captivity, the conditions of confinement and exposure to humans can...

Bacon, H. 2018. Behaviour-based husbandry—A holistic approach to the management of abnormal repetitive behaviors. Animals 8(7), 103.

The field of zoo animal welfare science has developed significantly over recent years. However despite this progress in terms of scientific research, globally, zoo animals still face many welfare challenges. Recently, animal welfare frameworks such...

Clegg, I. 2018. Cognitive bias in zoo animals: An optimistic outlook for welfare assessment. Animals 8(7), 104.

Cognitive bias testing measures how emotional states can affect cognitive processes, often described using the “glass half-full/half-empty” paradigm. Classical or operant conditioning is used to measure responses to ambiguous cues, and it has been reported...