# Evaluating Behavioral Management Practices for Laboratory Nonhuman Primates: An International Survey

## TL;DR

This study surveyed global practices in managing nonhuman primates in labs, finding regional differences in welfare standards and opportunities for improvement.

## Contribution

The largest international survey of behavioral management practices for laboratory nonhuman primates, comparing EU, UK, and US facilities.

## Key findings

- EU and UK facilities reported higher standards in social housing and enclosure size compared to US facilities.
- US facilities showed progress in exercise enclosures but lagged in other areas like destructible enrichment.
- Comparisons with past US surveys revealed some improvements over time but persistent challenges like staffing and costs.

## Abstract

Nonhuman primates are used in biomedical research worldwide, and improving their welfare is essential for ethical and scientific reasons. Behavioral management practices, such as social housing, environmental enrichment, and appropriate enclosure design, help animals express natural behaviors and reduce stress, but approaches vary internationally. This study reports the largest survey of behavioral management for research laboratory primates, gathering information from 49 facilities in the EU, UK and US. The survey examined key areas of social housing, nursery rearing, enclosure size and design, and types of enrichment. For the US, comparisons were made with previous surveys to identify changes over time, providing a unique perspective on long-term trends. Results show notable regional differences. EU and UK facilities generally reported higher standards, including more social housing and larger enclosures, while US facilities demonstrated progress in some areas, such as exercise enclosures, but with opportunities for further improvement in others. Cost, space, and staffing were commonly identified as challenges in the US. These findings provide valuable insights into recent practices and highlight opportunities for improvement through knowledge sharing and harmonized approaches. Strengthening behavioral management benefits animal welfare and enhances the quality of research, supporting global efforts to refine care and promote best practice.

The largest survey to date of behavioral management practices among facilities breeding and housing nonhuman primates (NHPs) for research was conducted from 2019 to 2020. Its primary objective was to analyze and compare practices across the European Union (EU), the United Kingdom (UK), and the United States of America (US), identify regional differences, and highlight opportunities for refinement. Detailed information was captured on the management of NHPs at 49 facilities in these regions. Most respondents reported the number of NHPs at their institutions, which totaled 50,842. The findings suggest large variation in NHP behavioral management practices between world regions. Facilities in the UK and EU are at the forefront of best practice in many components of behavioral management. These involve the proportion of NHP populations housed socially, the age at which infants are removed from dams, the provision of pen enclosures, caging exceeding the regulatory/accreditation minimum floor space, and destructible enrichment (including floor substrates). Comparisons with the results of previous surveys conducted in the US in 2003 and 2014 show positive changes and progress over time, including a greater proportion of facilities providing access to exercise enclosures with more frequent implementation. Some previously reported impediments to social housing involving clinical and staffing constraints as well as scientific instrumentation eased over time. While there were increases in the use of social housing for some species, there was no increase across all species over the six-year interval since 2014. The proportion of US facilities providing destructible enrichment for caged NHPs remained the same. Importantly, overall, the data demonstrate that, with knowledge transfer and sufficient resources, perceived constraints on key elements of behavioral management can be overcome to improve NHP welfare and facilitate good science. The findings have been used to identify and discuss recommendations for best practice to improve animal welfare.