Behavior in Salmon

The recent rapid development of biotelemetry technologies has made it possible to continuously observe the underwater behavior of salmon in open water. Homing migratory behaviors were studied using anadromous chum salmon from the Bering Sea to Hokkaido and lacustrine sockeye salmon and masu salmon in Lake Toya. Biotelemetry results on the migratory behavior of adult chum salmon in a reconstructed reach of the Shibetsu River; the investigation of cardiac arrest during gamete release in chum salmon; the comparison of the swimming ability and upstream-migration behavior of chum salmon and masu salmon in Hokkaido, Japan; and the analysis of site fidelity and habitat use in Formosan landlocked salmon during the typhoon season in the Chichiawan stream, Taiwan were also performed. This chapter describes the homing migration of anadromous chum salmon from the Bering Sea to Hokkaido, Japan; the homing migration of lacustrine sockeye salmon and masu salmon in Lake Toya, Hokkaido, Japan; and biotelemetry research on various behaviors in salmon.

Effects of culling intensity on diel and seasonal activity patterns of sika deer (Cervus nippon)

Adaptive hunting management is commonly used for controlling the populations of overabundant large herbivores; however, induced behavioural changes can make the effective control of target populations difficult. However, few studies have compared the impact of different levels of hunting intensities on the activity patterns of ungulates before, during, and after a culling program. We investigated how different culling intensities affect the activity patterns of sika deer on Nakanoshima Island in Lake Toya, Hokkaido, Japan using camera-trap surveys comparing the period of treatment before, during, and after a culling program. We used the number of deer photographed per hour per camera as an index of activity. Sika deer showed consistent crepuscular activity patterns (i.e., dawn and dusk) during spring–summer and trimodal activity patterns (i.e., dawn, dusk, and midnight) in autumn throughout the study period. In response to increased culling intensity, the activity peaks shifted slightly towards the night. The shift towards nocturnal activity persisted during post-culling period. Understanding the changes in activity patterns in response to culling intensity could be used to facilitate population control and assist in establishing a night shooting program. Thus, wildlife managers should consider night shooting once hunting during day time has shifted the normal diurnal activity of deer to nocturnal activity.