Can frequent occurrence of Asiatic black bears around residential areas be predicted by a model-based mast production in multiple Fagaceae species?

ABSTRACT

In Japan, there is a need to develop methods for predicting frequent occurrences of Asiatic black bears (Ursus thibetanus) around residential areas in order to prevent human–bear conflicts. Previous studies have suggested that the frequency of bear occurrence fluctuates dramatically from year to year and that this annual fluctuation is primarily correlated with mast production in Fagaceae trees. This study analyzed how three dominant Fagaceae species (Fagus crenata, Quercus crispula, and Quercus serrata) affect bear occurrences during autumn, constructing generalized linear models (GLMs) based on monitoring data collected over 12 years in Hyogo Prefecture, western Japan. According to the GLMs, each species affected bear occurrences differently. It is suggested that the effects for Q. crispula and Q. serrata on bear occurrence are larger than that for F. crenata. The accuracy of the predictive model increased as the number of Fagaceae species included in the model increased. The GLM with all three Fagaceae species showed a much closer relationship between observed values and expected values in bear occurrence (R² = 0.96). Frequent bear occurrences in western Japan can be predicted by monitoring fewer Fagaceae species (the three that are dominant there) than would be required in West Virginia, USA, for example. This study suggests that future research should focus on developing an even more reliable predictive model that would enable local communities to prepare for massive bear occurrences.

KEYWORDS:

• Model evaluation statistics
• generalized linear model (G.L.M)
• Fagus crenata
• Quercus crispula
• Quercus serrata

Acknowledgments

This study was made possible by excellent field assistance by many people, particularly Y. Goto and K Eto. I also thank the staff in the Wildlife Research Center, Hyogo and graduate students of University of Hyogo for assistance of field surveys.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

This work was supported by grants from Hyogo Prefectural Government and JSPS KAKENHI; [Grant number 18500783].