Highlands J (HJ) virus is a cause of encephalitis in chukar partridges. Chukars exhibit somnolence, ruffled feathers, and recumbency before death. HJ virus infection in this species is associated with high mortality. Microscopic lesions primarily consist of nonpurulent meningoencephalitis and focal myocardial necrosis. HJ virus is a potential cause of decreased egg production in turkeys. The virus has been identified only in eastern parts of the USA.