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Scavengers clean up wetlands and boost their health

Often associated with death and decay, scavengers – animals that consume carrion (dead animal matter) – play an unexpectedly vital role in maintaining the health and balance of wetland ecosystems. While they may not be the most charismatic of creatures, their ecological contributions are undeniable.

A study by researchers from the Ecology area of the Miguel Hernández University of Elche (UMH) and the Ecology department of the University of Alicante (UA) reveals the fundamental importance of scavengers and carrion in wetlands. 


Scavengers encompass a diverse range of species, including:


These large birds possess a keen sense of smell and excellent eyesight, enabling them to locate carcasses from great distances. Their powerful digestive systems allow them to safely consume decomposing flesh, preventing the spread of bacteria and pathogens.


Insects such as flies, beetles, and their larvae play a critical role in the initial decomposition of organic matter. They lay eggs within carrion, and their larvae consume the decaying flesh, breaking it down into smaller components and releasing nutrients into the environment.

Aquatic scavengers

Crayfish, certain fish species, and some crocodilians, like the gharial, opportunistically consume dead animal matter found in aquatic habitats. This contributes to the breakdown of organic material, prevents the buildup of harmful substances, and recycles nutrients within the aquatic ecosystem.

Essential functions of scavengers in wetlands

The recently published study underscores the numerous benefits scavengers provide to wetland ecosystems:

Nutrient cycling in wetlands by scavengers

When scavengers feed on dead animals, they break down complex organic compounds into simpler nutrients like nitrogen and phosphorus. These nutrients are then released back into the soil and water, where they can be absorbed by plants and algae. This process supports the growth of these primary producers, which form the base of the wetland food chain.

Regulation of water quality

By consuming decaying organic matter, scavengers help prevent its excessive accumulation within the wetland. If left unchecked, this buildup can lead to reduced oxygen levels (which harms fish and other aquatic life), increased water pollution, and the potential for harmful bacterial growth.

Scavenger’s ecosystem

Certain scavenging species, like crayfish, actively modify their wetland environment as they forage and create burrows. These disturbances increase the physical complexity of the habitat, creating niches for a wider variety of plants and animals. This, in turn, contributes to greater biodiversity and overall ecosystem health.

Knowledge gaps in scavengers and wetland ecosystems

While the general ecological functions of scavengers are understood, their specific roles and contributions within wetland ecosystems require further investigation.

There is a significant gap in knowledge compared to the extensive research on scavengers in terrestrial (land-based) environments. This targeted understanding is crucial for developing effective conservation strategies for wetlands.

Wetlands provide a multitude of benefits for both humans and wildlife. They naturally filter and purify water, help mitigate the impacts of floods, store carbon (helping combat climate change), and provide essential habitats for countless species.

The alarming loss of over 60% of the world’s wetlands in the last century underscores the critical need for research and action to conserve these remaining precious ecosystems.

Taking action for wetland health beyond scavengers

Here’s how you can contribute to the protection of wetlands and their often-overlooked inhabitants:

Support wetland conservation initiatives

To support wetland conservation initiatives effectively, you can start by understanding the various threats these ecosystems face, such as urban development, pollution, and climate change. Advocating for the protection and restoration of wetlands involves:

  • Educating yourself and others about the importance of wetlands: Learn how wetlands are not only biodiversity hotspots but also crucial for climate regulation and flood control.
  • Participating in local conservation projects: Look for opportunities to get involved with organizations that are working to restore wetland areas. This might include planting native species, cleaning up waterways, or monitoring wildlife.
  • Promoting and supporting policies that protect wetlands: Engage with policymakers and support legislation that aims to protect these ecosystems. This could involve writing to local representatives or supporting environmental NGOs that lobby for stronger environmental protections.

Minimize pollution

Minimizing pollution to protect wetland ecosystems and their inhabitants involves several key actions:

  • Be mindful of household chemicals: Choose environmentally friendly products for cleaning and gardening, which are less likely to harm the waterways if they run off into nearby drains or soils.
  • Proper disposal of waste: Dispose of hazardous wastes like paints, oils, and batteries at designated disposal facilities instead of dumping them down household drains or in the trash where they can leach into groundwater and surface water.
  • Reduce plastic usage: Plastics often end up in water bodies, harming aquatic and semi-aquatic wildlife. Opting for reusable products over single-use plastics can significantly reduce this impact.

Raise awareness

Raising awareness about the importance of scavengers and wetlands can lead to greater community involvement and support for conservation measures. You can raise awareness by:

  • Creating informative content: Use platforms like blogs, YouTube, or social media to share facts and information about wetlands and their role in the ecosystem. Include information about scavengers and how they contribute to environmental health.
  • Hosting educational events: Organize talks, webinars, or walks in local wetland areas with a focus on teaching community members about the ecological roles these environments play.
  • Engaging with schools: Work with local schools to include wetland conservation in their curriculum. This could involve field trips to wetlands or guest lectures from wildlife experts.

By undertaking these actions, you help ensure the health of wetland ecosystems and support the diverse life forms that rely on them for survival.

The next time you encounter a scavenger in its natural habitat, remember that it’s not just performing a mundane task – it’s fulfilling a crucial ecological role. By recognizing the often-overlooked value of scavengers, we can better appreciate the intricate balance of wetland ecosystems and the vital importance of their conservation.

The study is published in the journal Biological Reviews.


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