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. 
Winnicker, C., Gaskill, B., Garner, J. P. et al. 2016. A Guide to the Behavior & Enrichment of Laboratory Rodents. Charles River Laboratories.

Covering species-typical behavior as well as abnormal/malfunctional behavior and stereotypes observed in mice, rats, hamsters and gerbils, this is an excellent resource for those looking to implement or enhance an existing behavioral husbandry and enrichment...

Yamanashi, Y., Matsunaga, M., Shimada, K. et al. 2016. Introducing tool-based feeders to zoo-housed chimpanzees as a cognitive challenge: Spontaneous acquisition of new types of tool use and effects on behaviours and use of space. Journal of Zoo and Aquarium Research 4(3), 147-155.

Cognitively challenging environments are vital to the welfare of captive animals. However, practical enrichment devices that can facilitate animals’ natural behaviours and accommodate individual variation are still limited. We created two types of feeders to...

Leeds, A., Elsner, R., Lukas, K. 2016. The effect of positive reinforcement training on an adult female western lowland gorilla’s (Gorilla gorilla gorilla) rate of abnormal and aggressive behavior. Animal Behavior and Cognition 3(2), 78–87.

Positive reinforcement training (PRT) has become a widely used tool in improving the ease with which husbandry and veterinary procedures are performed for animals under human care. PRT provides positive social interaction, cognitive stimulation, and...

Crast, J., Bloomsmith, M. A., Jonesteller, T. 2015. Effects of changing housing conditions on mangabey behavior (Cercocebus atys): Spatial density, housing quality, and novelty effects. American Journal of Primatology 77(9), 1001-1014.

The separate influences of spatial density and housing quality on the behavior of captive animals are difficult to measure because the two factors are often intrinsically linked. Here, we recorded affiliative and agonistic behavior in...

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...

Bethell, E. J., Koyama, N. F. 2015. Happy hamsters? Enrichment induces positive judgement bias for mildly (but not truly) ambiguous cues to reward and punishment in Mesocricetus auratus. Royal Society Open Science 2, 140399.

Recent developments in the study of animal cognition and emotion have resulted in the ‘judgement bias’ model of animal welfare. Judgement biases describe the way in which changes in affective state are characterized by changes...

Washburn, D. 2015. The four Cs of psychological wellbeing: Lessons from three decades of computer-based environmental enrichment. Animal Behavior and Cognition 2(3), 218–232.

Three decades ago, the Animal Welfare Act was amended to require researchers to provide environments that promoted the psychological, as well as the physical, wellbeing of nonhuman primates maintained for research purposes. We developed a...

Charmoy, K., Sullivan, T., Miller, L. 2015. Impact of different forms of environmental enrichment on foraging and activity levels in gorillas (Gorilla gorilla gorilla). Animal Behavior and Cognition 2(3), 233–240.

The maintenance of species-specific behaviors for animals in zoological institutions is of top priority, as this can help ensure high levels of animal welfare. Strict feeding schedules within institutions can often impact natural foraging behaviors...

Monts de Oca, N., Diaz, L., McMahen, D. et al. 2014. The use of lean management principles to enhance a nonhuman primate environmental enrichment program. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 580-581. (Abstract #P122).

Sewage back-up and overflows in the rooms of our primate facility initiated an analysis of the factors contributing to the clogging of the drains. An investigation reviewing the materials responsible for the clogging of the...

Rose, A. M., Ferrecchia, C. E., Van Andel, R. 2014. Developing an enrichment plan for water-regulated nonhuman primates. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 565 (Abstract #P60).

Environmental enrichment for nonhuman primates is an essential requirement in laboratory animal research. The Animal Welfare Regulations and the Guide for the Care and Use of Laboratory Animals state that the facility’s enrichment program must...

Willey, S. 2014. Nonhuman primate enrichment room planning, design, and use. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 539 (Abstract #PS52).

Princeton University continually makes efforts to improve and enhance the quality of life of our NHPs used in research. A part of this effort is to continue to improve our environmental enrichment program, promoting the...

Qi, K., De-mi, S., Chuan, Q. 2014. Current understanding and use of environmental enrichment in China. Enrichment Record 20, 8-11.

In practice, consideration is given to providing most of the species used in research,testing and education withsome level of environmental enrichment. However, although the current level of awareness and understanding about the benefits of environmental...

Callan, T. 2014. Primates Presents. Enrichment Record 18, 5-6.

In the world of enrichment, ideas can be limitless. Sometimes, you just have to think outside the box... or in this case, "inside the box"! Who doesn't love a present with the colorful exterior and...

Alworth, L. C., Buerkle, S. C. 2013. The effects of music on animal physiology, behavior and welfare. Lab Animal 42(2), 54-61.

Physiological and psychological effects of listening to music have been documented in humans. The changes in physiology, cognition and brain chemistry and morphology induced by music have been studied in animal models, providing evidence that...

Reinhardt, V. (ed.) 2013. Compassion Makes a Difference - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume III. Animal Welfare Institute, Washington, DC.

This is the third volume of discussions that took place on the Laboratory Animal Refinement & Enrichment Forum (LAREF). This forum is dedicated to the exchange of personal experiences of refining the conditions under which...

Pierre, P. J., Torres, N. A., Rosga, M. D. et al. 2013. Colony-wide assessment of the foraging devices: Refinement of delivery practices, cost and the caloric content delivered via foraging devices. American Journal of Primatology 75(S1), 82. (36th Meeting of the American Society of Primatologists Scientific Program, Abstract #163)

Foraging opportunities are a key component of enrichment in captive nonhuman primates (NHP) providing manipulative opportunities in which animals can engage in species-typical behaviors. Recent studies suggest captive NHP populations have increased body weight over...

Hrapkiewicz, K., Colby, L. A., Denison, P. 2013. Clinical Laboratory Animal Medicine: An Introduction (4th Ed). Wiley-Blackwell, Ames, IA.

Clinical Laboratory Animal Medicine: An Introduction, Fourth Edition offers a user-friendly guide to the unique anatomy and physiology, care, common diseases, and treatment of small mammals and nonhuman primates. Carefully designed for ease of use...

Ryan, E. B., Proudfoot, K. L., Fraser, D. 2012. The effect of feeding enrichment methods on the behavior of captive Western lowland gorillas. Zoo Biology 31(2), 235-241.

Three feeding enrichment treatments were tested in an outdoor yard used by six Western lowland gorillas (Gorilla gorilla gorilla). In "Yard-toss", forage was thrown by hand over one third of the yard. In "Set-up", forage...

Olivo, D. 2012. The benefits of adding a little color to a monkey's environment. Enrichment Record 10, 7.

Imagine if your everyday world was boring, blah and completely sterile looking with limited amounts of color. Unimaginable, right? Here at Legacy Schering Plough/Merck, we thought the same about our nonhuman primates who look at...

Froberg-Fejko, K. M., Lecker, J. L. 2012. Going back to nature: The benefits of wood enrichment. Lab Animal 41(11), 345-347.

Environmental enrichment can be defined as altering the living environment of captive animals in order to provide them with opportunities to express more of their natural behavioral repertoire. The challenge of providing effective enrichment in...

Carey, M. C., West, A. M., Lozano, A. et al. 2012. Designing gum-based enrichment for captive patas monkeys (Erythrocebus patas). American Journal of Primatology 74(S1), 42. (35th Meeting of the American Society of Primatologists Scientific Program, Abstract #53)

In the wild, patas monkeys (Erythrocebus patas) consume Acacia spp. gum for 20% of their active time. While providing gum-based enrichment to other gummivorous primates is not a unique idea, there have been no reports...

Luchins, K. R., Baker, K. C., Gilbert, M. H. et al. 2011. Manzanita wood: A sanitizable enrichment option for nonhuman primates. JAALAS 50(6), 884-887.

Wooden objects are often used as nonhuman primate enrichment to provide variety and novelty, promote exploratory behavior, and supply an outlet for curiosity. However, concerns have been raised regarding the ability to sanitize wood by...

Wood, L. L., Boyd, A. M., Rose, R. et al. 2011. Implementation of an enrichment rack for singly housed male nonhuman primates. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 732 (Abstract #PS54).

The racks provide four different levels of horizontal bars where manipulanda can be hung. .. The racks are positioned in front of a 4-caged housing system. .. The enrichment racks have produced an increase in...

Malone, M. A., Leighty, K. A., Kuhar, C. W. et al. 2011. Behavioral response of silverback gorillas (Gorilla gorilla gorilla) to videos. Journal of Applied Animal Welfare Science 14(2), 96-108.

This study examined the impact of video presentations on the behavior of 4 silverback, western lowland gorillas (Gorilla gorilla gorilla). On each of 5 occasions, gorillas viewed 6 types of videos (blue screen, humans, an...

Huber, H. F., Lewis, K. P. 2011. An assessment of gum-based environmental enrichment for captive gummivorous primates. Zoo Biology 30(1), 71-78.

In the wild, many primates consume gums exuded from trees, and many species are gum specialists. In spite of this, few data exist concerning gum feeding in captivity. Using a web-based survey of 46 zoos...