It said the estate’s application contained no otter survey, on the assumption that there was no local population, even though Parnham’s website encourages visitors to “spot otter trails”.
The meadow’s albino badgers were also ignored in the documents, the group said.
Protected trees and valuable lichen were threatened in the Grade II listed deer park, it added.
In a statement, DNHI said: “Parnham’s entire approach towards this development… prioritises the partial restoration of a private estate over and above the wishes of the local community, destroying an irreplaceable natural habitat in the process.”