Muslim World Report

The Vanishing Scavengers and the Rising Threat to Human Health

Dr. Anthony Lindsay | Jun 24, 2025 10:19 AM | 9 min read | 1730 words

TL;DR: The decline of apex scavengers, especially vultures, poses a significant threat to ecosystems and human health by increasing the risk of zoonotic diseases. Their loss disrupts natural processes, leading to public health crises, particularly in vulnerable communities. Immediate action, awareness, and a shift in societal attitudes toward wildlife conservation are essential for mitigating these threats.

The Decline of Nature’s Scavengers: A Global Health Alarm

Recent research from Stanford University has unveiled a troubling trend that poses significant threats to both ecosystems and human health: the rapid decline of large scavenger animals, particularly apex scavengers like vultures. The study indicates that over one-third of 1,376 vertebrate species are now classified as threatened or declining, with scavengers experiencing the most severe losses (Sonawane et al., 2025). These species play an indispensable role in their ecosystems, cleaning up carrion and preventing the spread of diseases. As their populations dwindle, we face heightened risks of zoonotic diseases—those capable of transferring from animals to humans.

The Importance of Scavengers

Scavengers occupy a crucial niche in the ecosystem as nature’s cleanup crew, consuming dead animals and recycling nutrients back into the soil. They help prevent the spread of diseases that can arise from decomposing bodies. Key points include:

  • Digestive Systems: Vultures, for example, have strong digestive systems that allow them to consume carrion without falling ill from pathogens, thus breaking the cycle of disease transmission that could affect humans and domestic animals (Gibb et al., 2020).
  • Ecosystem Health: The decline of these species not only represents a loss of biodiversity but also threatens the health of the ecosystems they inhabit—ecosystems which in turn support human populations.

The implications of this decline are particularly alarming when considering the cascading effects on disease dynamics. In regions where vultures have disappeared, smaller scavengers, such as rats and feral dogs, have taken their place. These animals are less efficient at consuming carrion, resulting in an accumulation of decomposing remains that creates an ideal environment for the emergence and transmission of pathogens. Historical precedents, such as the vulture crisis in India, precipitated by the widespread use of diclofenac—a non-steroidal anti-inflammatory drug that proved lethal to vultures—demonstrate the interconnectedness of species health and human welfare. The dramatic 90% decline in vulture populations led to a public health crisis characterized by spikes in rabies and other zoonotic diseases as feral dog and rodent populations surged to fill the ecological void (Ripple et al., 2014; Frank & Sudarshan, 2023).

Global Relevance of Scavenger Decline

The global decline of scavengers reflects a broader issue of biodiversity loss and underscores the urgent need to reassess our relationship with the natural world. The health of our ecosystems is directly intertwined with human health; therefore, the decline of scavengers represents not merely an environmental concern but a looming public health crisis (Gibb et al., 2020). Key considerations include:

  • Strained Healthcare Systems: As countries contend with the fallout from these changes, the potential for widespread health issues threatens to impose immense strains on healthcare systems, particularly in already vulnerable communities.
  • Economic Impacts: The crisis serves as a stark wake-up call, challenging dominant narratives that prioritize economic growth over ecological stability.

What if scavengers continue to decline unchecked?

Should the decline of scavenger species continue unabated, we can expect:

  • Increase in Zoonotic Diseases: A significant rise in zoonotic diseases, echoing past incidents linked to vulture declines. The increased populations of less efficient scavengers, such as rats and feral dogs, could lead to higher incidences of diseases like rabies and leptospirosis, with far-reaching consequences for public health (Keesing & Ostfeld, 2021).
  • Healthcare Strain: Vulnerable populations, particularly in regions with limited healthcare access, will bear the brunt of these outbreaks, experiencing health crises and economic fallout as healthcare systems struggle to keep up with demand.
  • Economic Strain: The destabilization of public health systems could result in soaring healthcare costs and diminished productivity, exacerbating the cycle of poverty in already fragile communities.
  • Ecosystem Dynamics Shifts: Overpopulation of herbivores due to the absence of natural predators could lead to overgrazing, devastating agricultural lands and reducing food security (Young et al., 2014).

This scenario illustrates how the disappearance of scavengers can create a domino effect, impacting not only biodiversity but also sustainable agricultural practices and economic stability.

What if governments take immediate action?

If governments worldwide choose to act promptly on this critical issue, the outcomes could be significant, albeit complex. Potential actions include:

  • Restoration of Scavenger Populations: This would require habitat conservation, legal protection, and public awareness campaigns aimed at highlighting the vital role these species play in maintaining ecosystem health (Dirzo et al., 2014).
  • Strategies and Partnerships: Countries could adopt strategies similar to those employed for other endangered species, blending conservation efforts with community engagement to foster coexistence between humans and scavengers.
  • Sustainable Agricultural Practices: Rethinking agricultural practices that contribute to habitat loss and the decline of scavenger species could create a healthier environment for these vital species while promoting ecological balance.

The implications of proactive approaches could yield economic benefits through ecotourism and sustainable practices that uplift local communities. By prioritizing biodiversity, nations could enhance resilience against potential health crises, ultimately improving public health outcomes.

What if society adopts a new worldview toward nature?

Envisioning a societal shift toward a deeper recognition of our interconnectedness with nature could reshape our global landscape. If we collectively embrace a worldview that emphasizes the intrinsic value of all species, including scavengers, we may initiate transformative changes in how we interact with our environment. This shift would demand:

  • Widespread Education: Aimed at dismantling anthropocentric views of nature and promoting the importance of biodiversity for a sustainable future (Morand & Lajaunie, 2021).
  • Policy Changes: Cultural transformation could influence policy changes at local, national, and international levels, fostering collaborations among scientists, conservationists, and policymakers.

By acknowledging that healthy ecosystems are foundational to human health, society could mobilize resources toward safeguarding vulnerable species like vultures—not merely out of altruism but because their well-being is intrinsically linked to our survival.

Furthermore, a collective action approach could enhance resilience against climate change, as diverse ecosystems are better equipped to adapt to rapidly changing conditions. This new paradigm could drive innovation in sustainable practices that benefit both humanity and nature, ultimately leading to a healthier planet for future generations.

Strategic Maneuvers for Conservation

Given the gravity of the situation, a multi-faceted approach involving various stakeholders is essential to address the decline of scavenger species. Governments, non-governmental organizations (NGOs), local communities, and the international community must collaborate to forge comprehensive strategies aimed at both conservation and public health.

Government Initiatives

For governments, the first step should be enacting protective legislation for scavenger species. This may involve:

  • Stricter Regulations: On land use, habitat destruction, and the use of veterinary drugs that adversely impact scavengers.
  • Public Health Initiatives: Invest in initiatives that educate communities about the ecological roles of these animals and the potential health risks posed by their decline.

Collaboration with public health agencies will be vital to integrate eco-health perspectives into healthcare policies, ensuring that as we protect biodiversity, we also bolster human health (Wilkinson et al., 2018). Policies aimed at reducing habitat destruction, coupled with educational campaigns that explain the ecological importance of scavengers, can foster a sense of stewardship within communities.

Non-Governmental Organizations (NGOs)

NGOs can bridge the gap between communities and policymakers. They can:

  • Mobilize Resources: For conservation projects, spearhead awareness campaigns, and facilitate partnerships among stakeholders.
  • Engage Communities: By implementing community-based programs that incentivize the protection of scavenger species, creating sustainable livelihoods tied to ecological health.

For example, NGOs could collaborate with local farmers to create wildlife-friendly practices that benefit both agriculture and scavenger populations. Such collaborations can enhance community resilience and create win-win scenarios where both ecosystems and local economies thrive.

International Collaboration

At the international level, cooperation is paramount. Multinational agreements focusing on biodiversity conservation can provide frameworks for resource sharing and knowledge exchange, such as:

  • Best Practices Sharing: Countries that have successfully restored scavenger populations could share their best practices.
  • Funding for Conservation Efforts: Funds could be allocated to support conservation efforts in regions facing severe wildlife declines.

Global health authorities must also recognize the links between biodiversity and public health, integrating this understanding into health policy discussions (Levi et al., 2020). International bodies such as the World Health Organization (WHO) and the Convention on Biological Diversity (CBD) could play pivotal roles in creating synergies between health and environmental policies, advocating for conservation strategies that protect both nature and human populations.

Conclusion

The decline of scavengers is an urgent issue that intertwines ecological stability with public health. As we navigate the complexities of this predicament, it is essential to leverage interdisciplinary approaches that unite conservationists, health experts, policymakers, and communities. By recognizing the interconnectedness of all life forms and acting decisively to protect biodiversity, we can forge a healthier future for our planet and its inhabitants.

References

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  • Frank, E., & Sudarshan, A. (2023). The Social Costs of Keystone Species Collapse: Evidence from the Decline of Vultures in India. SSRN Electronic Journal.
  • Gibb, R., Franklinos, L. H. V., Redding, D. W., & Jones, K. E. (2020). Ecosystem perspectives are needed to manage zoonotic risks in a changing climate. BMJ, 375, n3389.
  • Keesing, F., & Ostfeld, R. S. (2021). Impacts of biodiversity and biodiversity loss on zoonotic diseases. Proceedings of the National Academy of Sciences, 118(8), e2023540118.
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  • Morand, S., & Lajaunie, C. (2021). Outbreaks of Vector-Borne and Zoonotic Diseases Are Associated With Changes in Forest Cover and Oil Palm Expansion at Global Scale. Frontiers in Veterinary Science, 8, 661063.
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  • Sonawane, C., Xu, M., Ward, N. C., et al. (2025). Global decline of apex scavengers threatens human health. Proceedings of the National Academy of Sciences, 122(1), e2417328122.
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