NABR Responds to IUCN's Classification of the Long-Tailed Macaque as Endangered

NABR’s Response to IUCN’s Endangered Classification for Long-Tailed Macaque

On October 9, 2025, the International Union for Conservation of Nature (IUCN) announced its decision to maintain the long-tailed macaque (Macaca fascicularis) within the endangered species category. This decision has drawn significant scrutiny, particularly from the National Association for Biomedical Research (NABR), which has contested the IUCN’s classification.

The NABR argues that the IUCN’s decision stems from misinterpretations of scientific data presented in a study by Hansen et al. They assert that these inaccuracies undermine the integrity of the classification process for this species. NABR’s position is grounded in a request submitted to IUCN in 2023, which aimed to challenge the basis on which the long-tailed macaque was deemed endangered. They also indicate that ongoing discussions surrounding potential conflicts of interest among the authors of the Hansen study warrant further investigation.

Criticism of IUCN’s Decision

Dr. Hank Jenkins, a researcher and advocate in the field, has formally requested the IUCN to look into possible conflicts of interest that may affect the decision-making process surrounding the classification of the long-tailed macaque. He highlighted that transparency regarding the authors of the review and their potential biases is vital to assure the scientific community and the public of the validity of the classifications being made.

Adding to the discourse, on October 7, 2024, the U.S. Fish and Wildlife Service rejected a petition from several conservation groups that sought to include long-tailed macaques under the Endangered Species Act (ESA). The Service cited a lack of credible information and evidence that suggested any real impact on the overall populations of the species. This rejection aligns with NABR's view that the long-tailed macaque’s status has been unjustifiably criticized.

Inconsistent Scientific Evidence

Dr. Ray Hilborn, a globally respected scientist and part of NABR’s scientific review team, expressed disappointment with IUCN, stating, “The lack of data on population trends and the distortion of existing data raise serious questions about the scientific approach used by IUCN in their decision-making.” This sentiment is shared across several scientific publications that call into question the methods utilized for the assessment of the macaque's population status.

Long-tailed macaques have found extensive use in biomedical research due to their physiological and genetic similarities to humans. These primates have contributed to major advancements in various medical fields, including oncology, vaccine development, and regenerative medicine. A recent report from the National Institutes of Health (NIH) reiterates the vital role that long-tailed macaques play in medical research, particularly amid the COVID-19 pandemic.

NABR’s Stance

Matthew R. Bailey, President of NABR, criticized IUCN’s decision to label the long-tailed macaque as endangered, despite the overwhelming scientific consensus against such classification. He asserted that ample evidence indicates this species should not be classified as endangered in any jurisdiction, with many nations categorizing long-tailed macaques as an invasive species instead.

Bailey raised concerns about the pressure from animal rights activists influencing IUCN’s stance, claiming, “It is perplexing that IUCN would describe this species as endangered while simultaneously acknowledging its invasive status in several countries.”

The ongoing debate highlights a critical intersection between conservation efforts and scientific integrity, drawing attention to the complexities of wildlife classification and the influence of external factors on policy-making. As NABR continues to advocate for transparent scientific evaluations, they maintain their commitment to informing stakeholders and the public about the importance of these discussions to ensure public health and the integrity of the scientific process.

For more information regarding NABR’s position and their ongoing efforts in biomedically responsible research policies, please visit their website at www.nabr.org.