A Study on dam-foal distance and their behavior in a herd of Hokkaido native horses using a drone

Abstract

The aim of this study was to investigate changes of dam- foal distance and their behavior in a herd of Hokkaido native horses. Twenty-two Hokkaido native horse foals born after December 2018 and their dams were observed using a drone (Mavic 2 pro) from May to October 2019. The dam-foal distance was measured from the recorded movie, and the behavior of the dam and foal was recorded visually. Data from 0-8-month-old foals and their dams were used for the analysis. The horses did not show any flight behavior during the drone flight when flight altitude was over 30m. It was clarified that the distribution of the dam-foal distance for each age is not normally distributed and can be approximated well by the geometric distribution (R²＝0.919). The change in the median dam-foal distance at each age changed between 4 month of age and 5 month of age. There was a significant positive correlation between dam-foal distance and age for foals aged between 0 and 4 months (P<0.01). On the other hand, there was a negative correlation between dam-foal distance and age for foals aged between 5 and 8 months. Furthermore, at age 0-4 months, there was a significant positive linear correlation (P<0.01) between the grazing duration of foal and dam- foal distance, but there was no significant correlation at age 5-8 months.