Video evidence of unusual antler-gnawing behavior of sika deer (Cervus nippon) in central Japan

Abstract

To compensate for mineral deficiencies in food sources, numerous ungulate species use various methods, such as salt licking, soil ingestion, and gnawing on antlers or bones. While osteophagia, the act of gnawing on antlers or bones, is well-documented in cervid species, it has only been observed in sika deer (Cervus nippon) on Mageshima Island in southern Japan despite their widespread distribution. This study aimed to provide an initial account of the observations of osteophagia in sika deer from central Japan. One of the 15 camera traps deployed in the Hakone Nature Forest of Tamagawa University for wildlife monitoring serendipitously captured multiple instances of adult female sika deer gnawing on a four-tined antler on July 9th and 16th in 2018. These occurrences coincided with the fawning season of the species during which mineral deficiencies in the diet are prevalent, suggesting that osteophagia serves as a response to nutrient deficiencies in the diet of sika deer in central Japan. Thus, systematic surveys may yield additional evidence of this behavior in sika deer across diverse geographical areas given the absence of studies on osteophagia in sika deer conducted in other regions. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo240508cn01a.