Cute but Dangerous? The Story of "Garbage and Evolution" Taught by Urban Raccoons

In the evening alleyway, a raccoon with a face like it's wearing a mask stares intently from the convenience store's garbage area——.

"Rummaging through the trash again..." you might frown, but according to the latest research, they might be more than just "nuisance animals." Signs of "evolution" toward becoming animals that live alongside humans are appearing in the bodies of raccoons living in cities.Phys.org

"Short Snouts" Found in Urban Raccoons

A research team led by Rafaela Lesch from the University of Arkansas at Little Rock analyzed about 20,000 photos of raccoons taken across North America, comparing individuals from urban and rural areas. They found that raccoons living in cities tend to have "shorter snouts" compared to those in the countryside.Phys.org

This "short snout" is considered one of the features that often appear in the early stages of domestication. The research paper, published in the journal 'Frontiers in Zoology,' has garnered significant attention for suggesting that the very shape of raccoons' bodies might be changing as they adapt to human habitats.Phys.org

What is the "Domestication Syndrome"?

Animals that have come to live near humans, such as dogs, cats, and livestock like pigs and cattle, exhibit certain common patterns. For example——

• Changes in fur color, such as parts of the body turning white

• Reduction in fangs and teeth

• Changes in ear and tail shapes, such as floppy ears and curled tails

• Roundness of the skull and facial features

• Decrease in aggression and a calm, friendly disposition

These changes are collectively called the "domestication syndrome," and it is recently thought to be related to the developmental process involving neural crest cells.Phys.org

Lesch and her team's research supports the hypothesis that the very early stages of this syndrome might be emerging in raccoons, which are not yet "fully domesticated" animals.

Is "Human Garbage" the Cause?

So why are only urban raccoons changing? Researchers point to the vast resource of "garbage" generated by human life.

Garbage bags filled with food waste, trash cans with loose lids, back doors of restaurants open late at night——these places are like all-you-can-eat buffets for raccoons. Individuals that are not too afraid of humans and can calmly rummage through trash cans can efficiently gather calories. Conversely, individuals that are overly aggressive or too timid to stay around humans may struggle to find enough food.Phys.org

Over a long timescale, "raccoons that can live near humans without being too afraid" are more likely to survive and leave offspring. As a result, changes similar to the domestication syndrome appear in their facial features and skull shapes——this is the interpretation of the study.

20,000 Photos Tell the Story of "Citizen Science"

A feature of this study is that it used a large number of photos taken by citizens, not just experts, for analysis. They measured the length of raccoon heads from various images, including trail cameras, surveillance cameras, and photos submitted by the public, and statistically examined the relationship with urbanization.Phys.org

Furthermore, the research team plans to 3D scan raccoon skulls stored at universities to verify whether the results estimated from photos are truly accurate. They also plan to extend the same method to other urban wildlife, such as armadillos and opossums. If similar trends are found across multiple species, the view that "cities are new stages for domestication" will become even more plausible.Phys.org

Will They Follow the Same Path as Dogs and Cats?

We humans have intentionally selected many dogs, cats, and livestock, favoring individuals we find "smart," "calm," and "manageable" for breeding. As a result, it is believed that dogs emerged from wolves and domestic cats from wildcats.

However, in the case of raccoons, humans are not actively trying to "domesticate" them. In fact, they are often disliked as "troublesome garbage raiders." Nevertheless, natural selection may be quietly and surely favoring individuals with traits that make it easier to live near humans.

If this process continues for decades or centuries——urban raccoons might become more round-faced, gentle, and less afraid of humans, resembling "semi-domesticated" animals. One researcher jokingly remarked, "If the next domesticated animal is the raccoon, it might be called the 'trash panda.'"Phys.org

The "Trash Panda Debate" Heats Up on Social Media

When this news was reported by overseas media, it quickly spread on social media, and the topic of "raccoon domestication" trended in the Japanese-speaking world as well. Various reactions are flowing through timelines.

"I thought they were just rummaging through trash, but they're on the forefront of evolution. Trash pandas are smart..."

"They're cute, but raccoons can carry rabies and parasites, so I hope they don't become 'pets' too easily."

"Isn't it too much of an environmental impact that human garbage can even change animals' bodies?"

"I hope a boom like 'The next trendy pet is the raccoon!' doesn't come. We should have learned from Rascal."

"Cities are no longer 'human-only spaces' but 'new ecosystems' where diverse creatures live together."

Some express optimism, saying, "If domestication makes them calmer, won't garbage damage decrease?" However, experts warn that if humans and raccoons get too close, the risk of infectious diseases and bite injuries may increase.

Urban Wildlife: More Than Just "Cute"

In Japan, raccoons are also a problem as invasive species in various regions. Individuals imported as pets have escaped or been released, and now they have become wild nationwide. Damage to crops and impacts on native species have become serious, and municipalities continue to capture and control them.

If urban raccoons show signs of domestication syndrome, it is evidence that they are "geniuses at adapting to human society" and that "human life is creating new ecosystems." While we are excitedly discussing "cute" and "interesting" on social media, quiet evolution may be progressing in the corners of cities.

How Should We Interact with Raccoons?

So, how should we face raccoons in the future?

1. Ensure Proper Garbage Management
   Using trash cans with lids and not leaving food waste out overnight can reduce "all-you-can-eat" opportunities for raccoons, helping prevent damage and weakening the unconscious push towards domestication by humans.

2. Avoid Approaching or Feeding Them
   Feeding them because they are "cute" encourages expansion of their range and familiarity with humans, ultimately increasing danger for both humans and animals.

3. Continue Scientific Monitoring
   Research like this provides important clues to visualize the impact of urban environments on living creatures. Participating in citizen science projects and supporting monitoring by municipalities and research institutions are actions we can take.
   
   
   

The "Evolution Story" Has Just Begun

Researchers are now working to accumulate more precise skeletal data to determine whether the differences between urban and rural raccoons are truly evolutionary changes or temporary environmental factors. If the same phenomenon is found in other urban wildlife like armadillos and opossums, an even more intriguing story may emerge, suggesting that by living with humans, wild animals are "domesticating" themselves.Phys.org

In the city's night, two eyes shine behind the convenience store. The owner is not just a "garbage scavenger" but perhaps a shrewd agent of evolution, continuously adapting to human society at this very moment. Whether our garbage and the urban stage will produce the next "domestic" animal——the answer lies with us humans.