Pet Rabbits Turn Into Invasive Feral Pests in the Wilderness

In the wild, domestic rabbits can become invasive feral pests, causing significant ecological and economic damage, researchers reveal how.

Short Summary:

• Study finds feral rabbits thrive due to mixed domestic and wild genetic origins.
• Rabbits becoming feral cause severe environmental and economic impacts.
• Insights into rabbit genetics may help manage invasive populations.

Domestic rabbits, widely adored as pets, can become invasive pests when reintroduced into the wild. Researchers from Uppsala University and BIOPOLIS-CIBIO have uncovered genetic secrets that enable these rabbits to adapt and thrive outside captivity. The study, involving the largest genetic dataset of rabbits ever assembled, reveals that feral rabbits, populations of once-domestic rabbits that returned to the wild, have a unique mix of domestic and wild origins. This genetic variability is key to their survival and colonization capabilities.

“Some changed so much from their wild ancestors, it is difficult to imagine they are related, like chihuahuas that descend from wolves,” explains Dr. Pedro Andrade, a researcher at BIOPOLIS-CIBIO and lead author of the study.

For years, scientists have pondered how domestic animals, optimized for life with humans, survive—and even thrive—when they return to the wild. Rabbits provide a fascinating case study. Historically, rabbits have been introduced to various regions by humans, often with disastrous results. For instance, the introduction of 24 rabbits by Englishman Thomas Austin to Australia in 1859 led to an ecological catastrophe, causing a dramatic spike in rabbit populations and significant environmental damage, as reported by Smithsonian Magazine.

The new study, published in the journal Nature Ecology & Evolution, sequenced the genomes of nearly 300 rabbits from six feral populations across Europe, South America, and Oceania, as well as domestic and wild rabbits from their native range in Southwest Europe. This extensive dataset provided crucial insights into the genetic makeup of feral rabbits.

“Domestic rabbits are so common, that our initial expectation was that these feral populations would be composed of domestic rabbits that somehow managed to re-adapt to the wild, but our findings point to a more complex scenario,” noted Dr. Miguel Carneiro, one of the senior authors of the study.

This complex scenario involves the elimination of genetic traits linked to domestication—a process driven by natural selection. Genetic variants that made rabbits more vulnerable to predators were often purged. For example, coat colors like albino or full black, common in domestic rabbits, were rarely seen in feral rabbits, highlighting the impact of predation pressures.

“In these feral populations, you will typically not see an albino, or a fully black rabbit, even if these fancy coat colors are very common in domestic rabbits,” adds Dr. Leif Andersson, professor at Uppsala University. “This is a concrete example of natural selection in action.”

The study also found strong natural selection acting on genes associated with behavior and the development of the nervous system. Traits linked to tameness, crucial for living close to humans, were often eliminated.

“Tameness is crucial for domestic animals to live close to humans, but it will not help a rabbit that finds itself back in the wild survive, so natural selection removes the genetic variants linked to tameness,” Dr. Andrade explains.

Understanding these genetic changes is not just academic. The findings have significant implications for managing invasive rabbit populations. Feral rabbits cause hundreds of millions of dollars in damages annually and threaten biodiversity. Their impact is so severe that in places like Paris and Vancouver, significant efforts are required to manage their populations and repair the damage they cause. For example, France24 reported extensive damage by feral rabbits to the lawns of the Esplanade des Invalides in Paris, estimated to cost about €366,000 (approximately $391,000 USD) in repairs.

Similarly, the Australian rabbit population, now over 200 million, has caused extensive environmental damage, leading to the extinction of many native ground-dwelling mammals and plants, exacerbating soil erosion, and destroying crops. To prevent such disasters, researchers emphasize the importance of controlling domestic rabbits and preventing their escape into the wild. In Hawaii, for example, laws require rabbits to be kept in raised hutches to prevent escape and safeguard the fragile ecosystem.

The findings also serve as a cautionary tale for other domestic animals that can turn feral. Feral pigs and cats are other examples of domestic animals causing substantial ecological damage. Researchers urge policymakers to utilize these insights to evaluate and mitigate future invasion risks effectively.

“The best strategy to mitigate the impacts of invasive species is to prevent them from being introduced in the first place, so we hope our study provides important evidence to help evaluate and identify future invasion risks,” Dr. Carneiro concludes.

For rabbit enthusiasts, understanding the potential ecological impact of feral rabbits is crucial. While they make delightful companions, ensuring they do not escape and contribute to wild populations is essential for maintaining ecological balance. To learn more about responsibly keeping rabbits as pets, visit BunnyEat.com, your ultimate destination for expert advice, quality products, and a supportive community dedicated to enhancing the lives of rabbits and their owners.

For further details on the genetic study, refer to the research paper: Andrade, P. et al. (2024). Selection against domestication alleles in introduced rabbit populations. Nature Ecology and Evolution. DOI: 10.1038/s41559-024-02443-3.

Contact Information:

• Leif Andersson; Uppsala University (Sweden), Texas A&M University (USA)
• Email: [email protected]
• Phone: +46 70 425 02 33