The sika deer is native to East Asia, including Japan, and primarily inhabits forests.
A dark line runs along the back toward a white rump patch. Males grow antlers.
Sika deer in Nara Park lower and raise their heads toward people holding deer cookies, a behaviour called bowing. They use places frequented by people, and the behaviour is associated with opportunities to obtain food. Their interactions with people have distinctive local characteristics.
A study published in 2023 examined deer habitat use and bowing during a sharp decline in visitors to Nara Park. Near the museum, researchers stood one metre from a deer and displayed cookies, filming head movements until the animal left or attacked the feeder. Mean bows per trial declined from 10.2 in 2016–2017 to 6.4 in 2020–2021. Monthly comparisons during the pandemic also showed more bowing when visitors were more numerous. Deer counted within the Todai-ji study site declined alongside visitors. Both the use of visitor areas and behaviour toward people changed.
An extinction-risk assessment has not been added yet.
In February 2025, the Nara Deer Preservation Foundation reported 2.9 kg of plastic waste in the first stomach of a pregnant female deer from the Todai-ji grounds. A traffic accident was considered the direct cause of death; the swallowed waste was described as an additional health concern. To prevent ingestion of food-scented rubbish, the foundation urged visitors to avoid feeding human food, take rubbish home and drive carefully around deer. These are local protection concerns for Nara’s deer.