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. 
Williams, E., Hunton, V., Hosey, G. et al. 2023. The impact of visitors on non-primate species in zoos: A quantitative review. Animals 13(7), 1178.

Visitors are a prominent feature in the lives of zoo animals, and their presence can cause a range of impacts on zoo animals (typically classed as positive, negative or neutral impacts), commonly referred to as...

Sweet, R., Cheyne, S. 2023. Hierarchical position of individual captive western lowland gorillas Gorilla gorilla gorilla and its impact on neighbour associations and behaviour. Journal of Zoo and Aquarium Research 11(2), 259–266.

This study investigated the social relationships observed within a captive breeding group of western lowland gorillas Gorilla gorilla gorilla at a European Association of Zoos and Aquaria (EAZA) accredited facility: Blackpool Zoo, UK. Gorillas are...

Leeds, A., Boyer, D., Ross, S. R. et al. 2021. Patterns of wounding in mixed-sex social groups of western lowland gorillas (Gorilla gorilla gorilla). Applied Animal Behaviour Science 236, 105226.

Long-term, multi-institutional assessments have become a reliable tool for evaluating patterns of wounding in zoo-living primates, with results informing on best practices for species-specific care protocols and population management strategies. For western lowland gorillas (Gorilla...

Gartland, K. N., Carrigan, J., White, F. J. 2021. Preliminary relationship between overnight separation and wounding in bachelor groups of western lowland gorillas (Gorilla gorilla gorilla). Applied Animal Behaviour Science 241, 105388.

Despite no significant difference in wounding between bachelor and mixed-sex groups of western lowland gorillas (Gorilla gorilla gorilla) in zoological settings, anecdotal concerns around the frequency and severity of wounding in bachelor groups have perpetuated...

Edes, A. N., Baskir, E., Bauman, K. L. et al. 2021. Effects of crowd size, composition, and noise level on pool use in a mixed-species penguin colony. Animal Behavior and Cognition 8(4), 507–520.

Studies on how visitors affect penguins in human care report a mixture of negative, neutral, and positive impacts on behavior and physiology. Swimming is a highly motivated behavior that may promote positive welfare in penguins...

O’Malley, M., Woods, J. M., Byrant, J. et al. 2021. How is Western lowland gorilla (Gorilla gorilla gorilla) behavior and physiology impacted by 360 degree visitor viewing access? Animal Behavior and Cognition 8(4), 468–480.

The effect visitors may have on the welfare of professionally managed animals is vital to consider. The present study utilized an experimental approach to examine how 360° visitor viewing access (i.e., viewing from all sides...

Leeds, A., Good, J., Schook, M. W. et al. 2020. Evaluating changes in salivary oxytocin and cortisol following positive reinforcement training in two adult male western lowland gorillas (Gorilla gorilla gorilla). Zoo Biology 39(1), 51-55.

Positive reinforcement training (PRT) is associated with increases in species-typical behavior and decreases in stereotypic and abnormal behavior in participating animals. Physiological changes following PRT, for example, increases in oxytocin (OXT) and/or decreases in cortisol...

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...

Heintz, M. R.; Fuller, G., Allard, S. 2019. Exploratory investigation of infrared thermography for measuring gorilla emotional responses to interactions with familiar humans. Animals 9(9), 604.

Interactions between zoo professionals and animals occur regularly and are believed to be enriching for animals. Little empirical information exists on how animals perceive these interactions, and particularly how the interactions affect the emotional states...

Coke, C., Skoumbourdis, E., Rodgers, J. C. et al. 2018. Blunting/cutting canines of adult male monkeys: A discussion by the Laboratory Animal Refinement & Enrichment Forum. Animal Technology & Welfare 17(2), 105-107.

"When you keep adult Rhesus macaque (Macaca mulatta) males, adult Cynomolgus (Macaca fascicularis) males or adult Vervet males (Chlorocebus pygerythrus), in the same enclosure, is it advisable to have the canines of the males blunted...

Cronin, K. A., Bethell, E. J., Jacobson, S. L. et al. 2018. Evaluating mood changes in response to anthropogenic noise with a response-slowing task in three species of zoo-housed primates. Animal Behavior and Cognition 5(2), 209–221.

In the zoo environment, anthropogenic noise is common as sound levels fluctuate due to visitors, construction, habitat design, and special events. In this study, changes in the mood of three species of zoo-housed primates in...

Sands, C., Evans, C., Buckmaster, C. A. 2017. The grooming sleeve: Encouraging conspecific-like behavior and strengthening the human-animal bond. Laboratory Animal Science Professional 5(2) (June), 52-53.

The act of grooming has been found to greatly decrease stress, heart rate, and cortisol levels in nonhuman primates; this decrease in stress and cortisol is seen in the animal being groomed, as well as...

Bayne, K. A., Beaver, B. V., Mench, J. A. et al. 2015. Laboratory animal behavior. In: Laboratory Animal Medicine, 3rd edition. Fox, J. G., Anderson, L., Otto, G., et al. (eds). Elsevier, Inc., Amsterdam, NL. pp. 1617-1651.

The study of laboratory animal behavior has increased steadily over the last decade, with expanding emphasis on a variety of commonly used species. In the United States, this trend was initially focused on species for...

Chelluri, G. I., Ross, S. R., Wagner, K. E. 2013. Behavioral correlates and welfare implications of informal interactions between caretakers and zoo-housed chimpanzees and gorillas. Applied Animal Behaviour Science 147, 306-315.

In captive animal facilities, human staff members are a relevant part of the animals’ social environment in addition to providing care and managing the social group. Structured, predictable interactions and relaxed, spontaneous contacts may all...

Bergman, T. J., Sheehan, M. J. 2013. Social knowledge and signal in primates. American Journal of Primatology 75(7), 683-694.

Primates are notable for having a rich and detailed understanding of their social environment and there has been great interest in the evolution and function of social knowledge in primates. Indeed, primates have been shown...

Hosey, G., Melfi, V. 2012. Human-animal bonds between zoo professionals and the animals in their care. Zoo Biology 31(1), 13-26.

Some human-animal relationships can be so positive that they confer emotional well-being to both partners and can thus be viewed as bonds. In this study, 130 delegates at zoo research and training events completed questionnaires...

Camacho, J. N., Boskovic, S., Moeller, E. 2012. Improved nonhuman primate social housing using visual cues associated for an intensive research study. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 636-637 (Abstract #PS35).

Lean management-based visual tools have been used to improve the quality of animal care associated with a complex research study involving immune-compromised cynomolgus monkeys (M. fascicularis) in various postsurgical recovery states. In order to effectively...

Baker, K. C. 2012. Implementation of pair housing for laboratory primates. American Journal of Primatology 74(S1), 31. (35th Meeting of the American Society of Primatologists Scientific Program, Abstract #20)

There is a general consensus among those studying the welfare of captive primates that social housing is the most effective means for promoting psychological well-being. It is well established that socially-housed rhesus macaques (Macaca mulatta)...

Schapiro, S. J., Bernacky, B. J. 2011. Socialization strategies and disease transmission in captive colonies of nonhuman primates. American Journal of Primatology 74(6), 518-527.

In captive research environments for nonhuman primates (NHP), social housing strategies are often in conflict with protocols designed to minimize disease transmission. This is particularly true in breeding colonies, and is especially relevant when attempting...

Coleman, K. 2011. Caring for nonhuman primates in biomedical research facilities: Scientific, moral and emotional considerations. American Journal of Primatology 73(3), 220-225.

Animal care for nonhuman primates (NHPs) in biomedical facilities has undergone major changes in the past few decades. Today, most primate facilities have dedicated and highly trained animal care technicians who go to great efforts...

Claxton, A. M. 2011. The potential of the human-animal relationship as an environmental enrichment for the welfare of zoo-housed animals. Applied Animal Behaviour Science 133(1), 1-10.

Environmental enrichment strategies are used to improve both the physiological and psychological welfare of captive animals, which can be achieved by increasing the expression of natural behaviour and decreasing abnormal behaviours. Examples of successful environmental...

Moreau, E. 2010. To squeeze or not to squeeze? A Discussion on LAREF, September, 2009. Laboratory Primate Newsletter 49(2), 3-4.

The discussion was started by the following questions: "Is the squeeze-back mechanism more or less stressful than the pole and collar system for removing a macaque from his cage for an IM (intramuscular) injection?" and...

Kuhar, C. W., Smith, K., Soltis, J. 2008. The visitor effect on apes: real or imaginary? Enriching or stressful? American Journal of Primatology 70(S1), 23 (31st Meeting of the American Society of Primatologists Scientific Program, Abstract #8).

The “visitor effect” problem, whether zoo visitors are stressful or enriching to zoo animals, is made difficult to analyze by numerous methodological challenges. The extremes in visitor attendance patterns during the holiday season at Disney’s...

Lutz, C. K., Novak, M. 2005. Environmental enrichment for nonhuman primates: Theory and application. ILAR Journal 46(2), 178-191.

Only social contact satisfies the goal of promoting a wide variety of species-typical activities while at the same time reducing or preventing the development of abnormal behavior... A number of toys should be provided initially...

Kulpa-Eddy, J. A., Taylor, S., Adams, K. M. 2005. USDA perspectives on environmental enrichment for animals. ILAR Journal 46(2), 83-94.

This article provides a brief historical background of the events and circumstances that led to the 1985 Animal Welfare Act (AWA) amendments. It describes the development of the regulations promulgated by the US Department of...