Sika deer and established woodlands, and public and private forestry bodies adopt policies of rigorous year-round culling. The main predators of sika deer include tigers, wolves, leopards, and brown bears. Lynx and golden eagles target fawns. Velvet antler (dried immature antlers) is a popular ingredient in traditional Chinese medicine, and sika in China were domesticated long ago for the antler trade, along with several other species. In Taiwan, both Formosan sika deer and Formosan sambar deer ("Cervus unicolor swinhoei") have been farmed for velvet antlers. Japan is the only country in eastern Asia where sika deer were not farmed for velvet antlers.
Sika Manu he was named in the final 24-man Kiwi squad and was part of the team that went on to win the tournament. In 2013 Sika, through his Tongan heritage, he made his début for Tonga in their Pacific Rugby League International clash with fierce Pacific rivals Samoa. Later in the year Sika represented Tonga in their unsuccessful 2013 Rugby League World Cup campaign. He played in all 3 of Tonga's matches, scoring two tries. He scored both of his tries in New Zealand's nail-biting 2 point defeat by Scotland (unfortunately the only defeat of their World Cup campaign which ultimately