Americans across several states have reported an increase in sightings of squirrels afflicted with a disfiguring poxvirus, leading some to dub the animals "zombie squirrels." The virus, known as squirrel fibromatosis, causes wart-like growths and tumors on the skin, sometimes leaving the animals with oozing sores and patchy fur.
Reports have emerged from Florida, North Carolina, Ohio, and Michigan. Jessie Crislip of Ashtabula, Ohio, shared images of a squirrel with visible warts on its eyes and head, expressing concern for the animal's suffering. Similarly, a North Carolina resident noted seeing multiple squirrels looking "like this" in early June, expressing personal unease.
Wildlife rehabilitation centers have also seen an increase in affected animals. Halfway Home Wildlife Rehab in Michigan reported taking in several squirrels infected with the poxvirus over the past month. Among them were three gray squirrels named Phlox, Bubbles, and Bugsy, all exhibiting significant skin lesions. Phlox, who arrived in early June covered in growths, showed significant improvement and was released back into the wild in late June. Bugsy is continuing to recover at the center, while Bubbles presented with sores on her eyes and genitals, alongside a maggot embedded in her fur.
Squirrel fibromatosis is caused by a leporipoxvirus and is spread through direct contact between infected and healthy squirrels, primarily through lesions or saliva. The growths can be hairless, break open, and leak fluid. While the disease can appear alarming, wildlife experts state that it is a naturally occurring condition and often runs its course without intervention. Shevenell Webb of the Maine Department of Inland Fisheries and Wildlife noted that cases can vary in severity, with some being localized and others systemic, which can be fatal.
Wildlife officials suggest that the increased sightings may be linked to homeowners using bird feeders. Concentrating squirrels in areas where they can easily spread the virus, potentially through saliva left on uneaten birdseed, is a possible contributing factor. Sightings of affected animals tend to rise during the summer months when squirrels are more active in their search for food.