Lots of mammals are capable of this, and we can determine which ones are even if we don't isolate the cause of thie pandemic.
SARS-CoV-2 also spreads exceptionally well on mink farms. Out of a total of 128 mink farms in the Netherlands, at least 69[0] had an outbreak of SARS-CoV-2 in 2020, with more suspected cases. On at least two farms, there were confirmed transmissions from the animals to farm workers. It is likely mink would form a natural reservoir SARS-CoV-2 if allowed to spread in the wild.
Mink farming has subsequently been banned since early 2021 in the Netherlands.
[0]: https://www.rijksoverheid.nl/onderwerpen/coronavirus-covid-1... (Dutch)