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

Takashi Ikeda,Yukiko Matsuura,Hiromasa Igota,Munemitsu Azumaya,Hiroshi Takahashi,Koichi Kaji,Tsuyoshi Yoshida

doi:10.1038/s41598-019-53727-9

Abstract

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.

Highlights

Adaptive hunting management is commonly used for controlling the populations of overabundant large herbivores; induced behavioural changes can make the effective control of target populations difficult
We investigated how different culling intensities affect the activity patterns of sika deer before, during, and after a culling program using camera-trap surveys and hypothesized that the activity patterns of sika deer would change from diurnal to nocturnal activity in response to increased culling intensity
Previous studies have found that the trimodal activity patterns of several ungulates (e.g. elk[23]; alpine chamois (Rupicapra rupicapra)[24]; white-lipped deer (Cervus albirostris)25) are influenced by feeding behaviour, rutting behaviour, and weather conditions

Summary

Introduction

Adaptive hunting management is commonly used for controlling the populations of overabundant large herbivores; induced behavioural changes can make the effective control of target populations difficult. 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. 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. Previous studies have reported that controlled hunting and recreational hunting decreased the harvest availability and observability of white-tailed deer, and suggested that it is important to manage refuge areas and human predation risk on game species in order to increase harvest efficacy and achieve the desired management objectives[12,13]. Some studies have found an association between hunting activity and the diel activity patterns of ungulates (white-tailed deer[18], red brocket deer (Mazama Americana)[19], sika deer (Cervus nippon) and wild boar (Sus scrofa)20,21), resulting in increases nocturnal activity during the hunting season and in areas with low protection

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Conclusion