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...

Coleman, K., Shapiro, S. J. (Eds.). 2021. Behavioral Biology of Laboratory Animals (1st ed). CRC Press, Boca Raton, FL.

This 30-chapter volume informs students and professionals about the behavioral biology of animals commonly housed in laboratory and other captive settings. Each species evolved under specific environmental conditions, resulting in unique behavioral patterns, many of...

Alnes, I. B., Jensen, K. H., Skorping, A. et al. 2021. Ontogenetic change in behavioral responses to structural enrichment from fry to parr in juvenile Atlantic salmon (Salmo salar L.). Frontiers in Veterinary Science 8, 638888.

Enrichment is widely used as a tool for studying how changes in environment affect animal behavior. Here, we report an experimental study investigating if behaviors shaped by stimuli from environmental enrichment depending on the stage...

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...

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...

Monreal-Pawlowsky, T., Vaicekauskaitė , R., Palencia Membrive, G. et al. 2021. Goal-oriented behavioural and environmental enrichment in aquarium species. Journal of Zoo and Aquarium Research, 9(4), 273-280.

Environmental enrichment is a common tool used in zoo and aquarium settings to provide mental and physical stimulation to animals under human care. This paper aims to present a primary approach to goal-oriented environmental and...

Janhunen, M., Piironen, J., Vainikka, A. et al. 2021. The effects of environmental enrichment on hatchery-performance, smolt migration and capture rates in landlocked Atlantic salmon. PLOS ONE 16(12), e0260944.

Enrichment of rearing environment with natural elements has been suggested to improve the welfare and post-release survival of cultured fish. We studied the combined effects of shelter structures, periodical water flow and water level changes...

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...

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...

Petrović, T. G., Vučić, T. Z., Nikolić, S. Z. et al. 2020. The effect of shelter on oxidative stress and aggressive behavior in crested newt larvae (Triturus spp.). Animals 10(4), 603.

Shelters are important for animal survival. Provision of adequate hiding places allow animals to express their natural sheltering behavior and it can have different positive effects on cortisol levels, physiological processes and mental performance. Although...

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...

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...

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...

Mather, J. A. 2019. Ethics and care: For animals, not just mammals. Animals 9(12), 1018.

Animals come in a huge array of types, species and structures, but without realizing it, we have focused our care on those like us, mammals. They look something like us, so it's easy to empathize...

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...

Wolfensohn, S., Shotton, J., Bowley, H. et al. 2018. Assessment of welfare in zoo animals: Towards optimum quality of life. Animals 8(7), 110.

Zoos are required to maintain a high standard of animal welfare, and this can be assessed using a combination of resource-based and animal-based indices usually divided into behavioural indicators, physiological indicators and clinical/pathological signs. Modern...

Wagman, J. D., Lukas, K. E., Dennis, P. M. et al. 2018. A work-for-food enrichment program increases exploration and decreases stereotypies in four species of bears. Zoo Biology 37(1), 3–15.

Zoo‐housed bears are prone to exhibiting stereotypic behaviors, generally considered indicators of negative welfare. We explored the effects of a variable‐time feeding enrichment schedule on behavioral indicators of welfare in four bear species at Cleveland...