NABR Responds to IUCN’s Decision on Long-Tailed Macaques Status Amid Controversy

NABR Critique on IUCN’s Endangered Status for Long-Tailed Macaques

On October 9, 2025, the International Union for Conservation of Nature (IUCN) made a significant decision to maintain the "endangered" classification for long-tailed macaques (Macaca fascicularis). This announcement has sparked a heated response from the National Association for Biomedical Research (NABR), which had previously challenged the IUCN's findings. The NABR's challenge centers around the assertion that the IUCN's assessment was based on flawed scientific interpretations put forth by researchers such as Hansen and others.

The NABR’s petition, submitted in 2023, argued that the scientific data used by the IUCN lacked credibility and misrepresented the true dynamics related to the species' population. They provided evidence that the reviews cited by IUCN do not reflect the latest scientific understanding. Dr. Ray Hilborn, a prominent scientist and NABR member, expressed his disappointment in the IUCN’s decision, stating, "The absence of reliable data on population trends and the misinterpretation of existing data raise serious doubts about the scientific process undertaken by IUCN in arriving at this decision."

In a contrasting evaluation, the U.S. Fish and Wildlife Service rejected a petition that sought to classify long-tailed macaques as endangered under the Endangered Species Act (ESA). The Service concluded that the petition did not contain credible information substantiating the impact on the species' overall population. This decision underscores a growing divide in the interpretation of data regarding the status of long-tailed macaques, highlighting that no government worldwide recognizes this species as endangered.

The ongoing debate is intensified by claims from various stakeholders. A separate petition filed by Dr. Hank Jenkins to the IUCN questions the integrity of the studies authored by Hansen, particularly with respect to alleged conflicts of interest that necessitate further investigation. However, the potential existence of these conflicts remains unclear, which adds another layer of complexity to the IUCN’s process in assessing the long-tailed macaque’s status.

NABR highlights the critical importance of long-tailed macaques in biomedical research due to their physiological and genetic similarities to humans. With over five of the top twenty prescription drugs developed using contributions from this species, their significance in advancing fields like regenerative medicine and vaccine development is undeniable. A recently published report by the National Institutes of Health reiterated the vital role of long-tailed macaques in the scientific community, calling into question the validity of IUCN's current stance.

Matthew R. Bailey, the president of NABR, criticized the IUCN for succumbing to activist pressures despite overwhelming scientific evidence asserting that long-tailed macaques are not endangered. He noted, "It’s perplexing that IUCN would classify this species as endangered while also acknowledging it as one of the most invasive species globally. The scientific information available clearly indicates that this species is not at risk; in fact, in several countries, they are regarded as invasive."

Amidst these discussions, long-tailed macaques have drawn attention as part of a broader investigation by the House Oversight Committee in the United States, which scrutinizes PETA and other animal rights organizations for alleged attempts to improperly influence government inquiries involving private entities and foreign governments. This situation exemplifies a contentious intersection of science and advocacy.

As per a publication listing the world's 100 worst invasive alien species, long-tailed macaques have been flagged by IUCN as an invasive species. The NABR continues to advocate for a science-driven policy regarding animal research and to educate policymakers and the public about their importance in contributing to health advancements.

The NABR's critical perspective raises essential questions regarding the interplay between scientific integrity, animal rights activism, and public policy. The outcome of the IUCN's decision could have profound implications for future research practices and conservation strategies. For further details on NABR’s position and their ongoing efforts, the organization invites the public to visit their official site, NABR.

References

1. Hilborn, R. and Smith, D. R. (2023). Is the long-tailed macaque at risk of extinction? American Journal of Primatology.
2. Hilborn, R. and Smith, D. R. (2025). Estimating the abundance of widely distributed primates. American Journal of Primatology.
3. Albrecht, L., et al. (2021). COVID-19 Research Lessons from Non-Human Primate Models.
4. IUCN, 100 of the World's Worst Invasive Alien Species.

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