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03-13-2024

Why birds enjoy eating feces and what it means for their health

Forget the early bird getting the worm. A new study by the University of South Australia reveals a surprising breakfast choice for some birds: poo. Moreover, birds aren’t picky feces eaters. They can even go for droppings from other species.

This behavior, called coprophagy, might seem unusual, but researchers believe it’s a vital survival strategy for birds.

Feces supports bird digestion

Dr. Barbara Drigo, lead author of the study, explained that consuming feces significantly boosts the birds’ digestive systems. It allows them to absorb essential nutrients they might otherwise miss.

This adaptation is especially important for long-distance migratory birds, which constantly switch between periods of no food and intense feeding during their global journeys. The ingested feces modify the bacteria and microbes living in the birds’ guts. This microbial shift allows the birds to adjust to new environments and food sources, particularly during seasonal changes.

But the benefits go beyond just nutrition. The research suggests that coprophagy might also be a form of self-medication, helping birds fight off infections. However, this intriguing theory needs further investigation to be confirmed.

Bird microbiome enhanced by feces

A healthy gut microbiome, teeming with diverse microbes, is essential for birds. The tiny residents play a vital role in digestion, immune response, and disease resistance. This dynamic community isn’t fixed; it’s constantly influenced by food, surroundings, and behaviors like coprophagy.

Humans often offer birds seemingly harmless treats like bread. However, bread, especially in large quantities, disrupts the delicate balance of bird’s gut microbes.

Unlike their natural, diverse diets, bread offers minimal nutrition and reduces gut microbial diversity. This decline weakens a bird’s ability to digest food effectively, fight infections, and stay healthy.

By consuming feces, birds can reintroduce or enrich beneficial gut microbes. These microbes improve digestion and nutrient absorption, potentially mitigating the negative impacts of subpar diets like those high in bread. This behavior is particularly valuable when natural food sources are scarce or seasonal.

Maintaining a balanced ecosystem

Birds play a critical role in seed dispersal, pest control, and the food chain. Their health and behavior directly impact the health of entire ecosystems. Therefore, supporting a healthy avian gut microbiome is essential not only for bird well-being but also for a balanced ecosystem.

The study’s findings highlight the interconnectedness of diet, gut health, and the environment. Experts urge us to reconsider practices like feeding bread to birds, which disrupt natural processes. Encouraging natural foraging and protecting natural habitats are key to supporting healthy bird populations and, consequently, a healthy planet.

Diseases due to coprophagy

The study also highlights significant health risks related to birds eating feces. One major concern is disease transmission. Migratory birds, with their vast ranges, can efficiently spread pathogens across continents.

This movement increases the risk of disease spread not only among bird populations but potentially to humans, especially in areas with close bird-human interaction.

Coprophagy, whether consuming feces from their own species (allocoprophagy) or different species (heterospecific coprophagy), opens the door to ingesting harmful pathogens like bacteria, viruses, and parasites.

“Depending on their geographical range, behaviour and interactions with other animals and environments, birds – especially migratory ones – can efficiently spread pathogens around the world,” Drigo noted.

Antimicrobial resistance

Another critical issue identified by Drigo’s research is exposure to antimicrobials like pesticides and cleaning products found in human-dominated environments.

“Birds foraging in human environments are exposed to chemicals and metals from waste, sewage and refuse, which can alter their microbiota, potentially leading to antimicrobial resistance.” explained Drigo.

This is further exacerbated by the presence of various chemicals and heavy metals in these environments, potentially leading to increased AMR. AMR is a threat not only for the birds’ health but also for public health.

The spread of resistant bacteria from wildlife to humans, particularly in areas with close interaction, could render antibiotics and other antimicrobials ineffective in treating human infections.

Study significance

The study serves as a call to action for scientists to investigate how coprophagy affects birds throughout their lives and across diverse environments. Understanding this behavior better is crucial for a more holistic view of avian health.

Coprophagy, though initially shocking, demonstrates the incredible ways animals adapt to their surroundings. The study serves as a powerful reminder of nature’s complexity and the endless discoveries waiting to be unveiled with a keen eye.

For those fascinated by the secrets of bird diets, the research offers a window into the hidden world of birds. As we strive to understand the interplay between nutrition, health, and the environment, scientists continue to illuminate the interconnectedness of life on Earth.

The research is published in the journal Biological Reviews.

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