We cannot ignore the unintentional capture of non-target species

Abstract

In recent years, cases of unintentional capture of non-target species such as bears, Japanese serow, and medium-sized mammals by both box and snare traps set for sika deer and wild boar seems to be increasing in Japan. The strong promotion of the wild boar control program by the government, the expansion of classical swine fever among wild boar, increasingly inexperienced trappers, and range expansions of sika deer and wild boar in the northern part of Honshu Island may also be driving this phenomenon. The detriments of unintentional capture are: 1) impact on ecosystem, 2) decline in capture efficiency (CPUE), 3) risks to hunters and hikers, 4) increase in cost for governmental oversight agencies, 5) decrease in capture motivation of trappers, and 6) animal welfare.

Two tasks are thus equally urgent: reducing unintentional captures of non-target species, and controlling population levels of both sika deer and wild boar. As a bottom-up strategy, it is necessary to elucidate the occurrence mechanism of the unintentional captures and to develop a process to reduce them. As a top-down strategy, it is necessary to establish an information-gathering system for unintentional capture at the national level to monitor the situation in real time. Legal action will also be required to some extent.