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. 
Lambert, K. 2021. DIY: Busy boxes. Laboratory Animal Science Professional 9(6) (November/December), 32.

This article describes the ingredients and directions to make this simple DIY destructible enrichment for NHP and swine.

Vining, A. Q., Nunn, C. L., Samson, D. R. 2021. Enriched sleep environments lengthen lemur sleep duration. PLOS ONE 16(11), e0253251.

Characteristics of the sleep-site are thought to influence the quality and duration of primate sleep, yet only a handful of studies have investigated these links experimentally. Using actigraphy and infrared videography, we quantified sleep in...

Brooks, J., Yoshimura, H., Taki, Y. 2021. Knowledge-based enrichment: Development of a novel enrichment device for captive chimpanzees. Zoo Biology 40(5), 398-406.

The field of environmental enrichment has grown considerably, but most enrichment is still focused on tasks where highly valued food rewards are directly visible. We designed a device which would instead make use of knowledge...

Laméris, D. W., Verspeek, J., Depoortere, A. et al. 2021. Effects of enclosure and environmental enrichment on the behaviour of ring-tailed lemurs (Lemur catta). Journal of Zoological and Botanical Gardens 2(2), 164–173.

Environmental enrichment is widely used to improve the quality of life of animals under human care. To successfully implement enrichment programs, it is important to evaluate their effect in different enclosure types since housing conditions...

Matsuzawa, T. 2020. WISH cages: Constructing multiple habitats for captive chimpanzees. Primates 61(2), 139–148.

This article aims to introduce environmental enrichment for captive chimpanzees in Japan in a historical context. It describes the most recent endeavor of constructing huge cages and connecting multiple habitats. The Ai Project, a series...

Skalníková, P., Frynta, D., Abramjan, A. et al. 2020. Spontaneous color preferences in rhesus monkeys: What is the advantage of primate trichromacy? Behavioural Processes 174, 104084.

Color perception and color signaling play an important role in various aspects of animal behavior. However, in mammals, trichromatic vision characterized by three retinal photopigments tuned to peak short, middle and long wavelengths is limited...

Regaiolli, B., Angelosante, C., Marliani, G. et al. 2020. Gum feeder as environmental enrichment for zoo marmosets and tamarins. Zoo Biology 39(2), 73-82.

Tamarins and marmosets are small-bodied social callitrichines. Wild callitrichines feed on exudates, such as sap and gum; particularly, marmosets are mainly gummivores, while tamarins consume gums only occasionally and opportunistically. Zoo marmosets and tamarins are...

Ebel, S. J., Kopp, K. S., Liebal, K. 2020. Object preferences in captive Sumatran orang-utans (Pongo abelii). Behavioural Processes 170, 103993.

While preferences for perceptual features of objects are well studied in humans, little is known about this trait in other great apes. We therefore presented captive Sumatran orang-utans (Pongo abelii) with objects that differed in...

Inoue, N., Shimada, M. 2020. Comparisons of activity budgets, interactions, and social structures in captive and wild chimpanzees (Pan troglodytes). Animals 10(6), 1063.

Chimpanzees in zoos with sufficient and appropriate environmental enrichment devices are expected to exhibit behaviors, interactions, and societies similar to those in the wild. In this study, we compared the activity budgets of each observed...

Reinhardt, V. (ed.) 2020. It’s Okay to Cry - Discussions by the Laboratory Animal Refinement & Enrichment Forum [LAREF], Volume V. Animal Welfare Institute, Washington, DC.

This is the 5th volume of selected discussions that took place on the electronic Laboratory Animal Refinement & Enrichment Forum between February 2016 and December 2019. The forum was created in October 2002; it allows...

Greene, L. K., Clarke, T. A., Southworth, C. A. et al. 2020. Daily lettuce supplements promote foraging behavior and modify the gut microbiota in captive frugivores. Zoo Biology 39(5), 334-344.

For captive primates, greater provisioning of leafy greens or foliage can promote natural foraging behavior while boosting fiber intake. Recalcitrant fiber, although minimally available to endogenous metabolism, is readily fermented into nutrients by gut microbes...

Verspeek, J., Stevens, J. M. G. 2020. Food preference and nutrient composition in captive bonobos (Pan paniscus). Primates 61(5), 661-671.

Food preference has been studied in a range of Hominoidea in the wild and in captivity, allowing for interspecific comparisons. Chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla gorilla) prefer low-fibre, high-sugar foods, suggesting that frugivory...

Yamanashi, Y., Bando, H., Matsunaga, M. et al. 2020. Development of bed-building behaviors in captive chimpanzees (Pan troglodytes): Implication for critical period hypothesis and captive management. Primates 61(5), 639-646.

Wild great apes build beds for sleeping by combining tree branches or other vegetation, but the development of this behavior is poorly understood. We investigated the development of bed-building behaviors by conducting complementary cross-sectional and...

Mellor, E. L., Cuthill, I. C., Schwitzer, C. et al. 2020. Large lemurs: Ecological, demographic and environmental risk factors for weight gain in captivity. Animals 10(8), 1443.

Excessive body mass, i.e., being overweight or obese, is a health concern associated with issues such as reduced fertility and lifespan. Some lemur species are prone to extreme weight gain in captivity, yet others are...

Coventry, C. 2020. Positive reinforcement training as physiotherapy for a brown capuchin (Sapajus apella). RATEL (Journal of the Association of British and Irish Wild Animal Keepers) 47(2), 16-17.

Physiotherapy can be used to treat an animal following surgery, to help correcting abnormal gait and for treating tendon, bone or ligament damage. […] Of course, an animal can’t just be given a set of...

Perea Garcia, J. O., Miani, A., Kristian Olsen Alstrup, A. et al. 2020. Orangulas: Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan (Pongo pygmaeus): Effect of scheduled visual enrichment on behavioral and endocrine aspects of a captive orangutan. Journal of Zoo and Aquarium Research, 8(1), 67-72.

Captivity may have adverse effects on captive great apes, who would spend much more of their time engaged in foraging and other activities in the wild. Enrichment interventions have the potential to alleviate the adverse...

Boesch, C. 2020. Mothers, environment, and ontogeny affect cognition. Animal Behavior and Cognition 7(3), 474–489.

The book “Folk Physics for Apes” remains a fascinating book about the way one captive peer-group of chimpanzees understand the world in which they grew. However, the very special living conditions these seven individuals faced...

Jacobson, S. L., Kwiatt, A. C., Ross, S. R. et al. 2019. The effects of cognitive testing on the welfare of zoo-housed Japanese macaques (Macaca fuscata). Applied Animal Behaviour Science 212, 90-97.

Cognitive testing programs are being implemented more frequently in zoo settings due to the benefits these programs can provide for the animals, researchers and zoo visitors. However, the impact that cognitive studies have on the...

Bliss-Moreau, E., Baxter, M. G. 2019. Interest in non-social novel stimuli as a function of age in rhesus monkeys. Royal Society Open Science 6(9), 182237.

Human cognitive and affective life changes with healthy ageing; cognitive capacity declines while emotional life becomes more positive and social relationships are prioritized. This may reflect an awareness of limited lifetime unique to humans, leading...

Bloomsmith, M. A., Clay, A. W., Lambeth, S. P. et al. 2019. Survey of behavioral indices of welfare in research chimpanzees (Pan troglodytes) in the United States. JAALAS 58(2), 160-177.

Chimpanzees demand specialized housing and care and the highest degree of attention to animal welfare. The current project used a survey method to collate information on chimpanzee housing and behavioral indices of welfare across all...

Animal Welfare Institute. 2019. Let’s get serious about animal play. AWI Quarterly 68(3) Fall, 19.

This article describes the importance of providing laboratory animals with opportunities to engage in play, and provides a few practical ideas for how to do this.

Heyworth, C. 2019. Inventive enrichment to facilitate weight gain in the common marmoset (Callithrix jacchus) during invasive studies. Laboratory Animal Science Professional 7(4) (December), 38-41.

To provide the highest standard of care to marmosets during invasive surgical studies, studies that often lead to weight loss, it is paramount to call upon inherent species-specific enrichment tactics to mitigate weight loss. Weight...

Anderson, J. R., Ang, M. Y. L., Lock, L. C. et al. 2019. Nesting, sleeping, and nighttime behaviors in wild and captive great apes. Primates 60(4), 321–332.

The past few decades have seen a burgeoning of scientific studies on great apes’ use of nests for sleeping in the wild, as well as their nesting behavior and sleep in captivity. We review recent...

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...

Leeds, A., Lukas, K. E. 2019. Monitoring the social behavior of a bachelor mandrill (Mandrillus sphinx) dyad participating in touchscreen-mediated cognitive testing. Zoo Biology 38(4), 397-402.

Cognitive testing of primates in zoos is becoming increasingly common. Cognition experiments are generally thought to be beneficial as they provide participants with an opportunity to engage in species-specific cognitive functioning, perhaps more so than...