About 80 percent of Iowa deer tested between late November 2020 and early January were infected with the pandemic coronavirus according to a New York Times report. The deer picked up mutations and variants in similar patterns to humans across the state, suggesting humans passed infections to deer multiple times.
The rapid rise in the prevalence of infections indicates that the deer are also spreading SARS-CoV-2 to one another, as found in a study posted on the preprint repository bioRxiv.
Source: Science, November 4, 2021. Link. Researchers have yet to determine if deer can pass the virus back to humans, or whether other wild animals are also transmitting the virus.