Introduction

Water birds prefer Korea as a stopover and wintering location because of the country’s favorable geographic conditions. It is reported that over 1,340,000 domestic water birds overwintered as of 2020 (National Institute of Biological Resources [NIBR], 2020). The spot-billed duck is the third most abundant species of ducks in Korea (NIBR, 2020). However, the spot-billed ducks peaked in 2000 and currently has 100,000 (NIBR, 2020). The spot-billed ducks prefer eating on farmland, despite their primary habitats being rivers, lakes, and reservoirs (Stafford et al., 2010). The average daily distance traveled by the spot-billed duck is 1.0±0.89 km, with a maximum of 23 km (Shin et al., 2016c). Factors such as food resources, the quantity of food, and human interference influence the migration routes of the spot-billed ducks (Davis & Afton, 2010; Kang et al., 2014; Shin et al., 2016a). Typically, the spot-billed duck spends the day resting in lakes and rivers and the night foraging in fields (Baldassarre & Bolen, 1994). The spot-billed duck has a sustainable breeding population in Korea. However, most research on the spot-billed ducks has been conducted during winter. Therefore, this study aimed to elucidate the home range and habitat use of spot-billed ducks in spring to protect and manage this species.

Materials and Methods

Results

Discussion

The winter home range (KDE 50%) of spot-billed ducks includes more urban than rural areas (Hwang et al., 2016). From these findings, we conclude that the spring home range (KDE 50%) of the spot-billed duck was similar to that of the rural areas and smaller than in urban areas (Hwang et al., 2016). Spot-billed ducks, like other duck species, show differences in mobility and home range depending on environmental and anthropogenic factors (Davis & Afton, 2010; Kang et al., 2014; Yoo et al., 2008). A limited home range in the spring allows for the provision of food and a hiding spot according to the grass Therefore, they used a small home range and avoided extensive travel during the spring.

Wetlands (41.5%) and rice fields (35.7%) were found to be highly utilized by spot-billed ducks. The utilization rate of rice fields was high during the day, whereas that of wetlands was high at night. This was comparable to the wintertime habitat usage rate in rural areas (Hwang et al., 2016). The spot-billed ducks typically inhabit wetlands and rice fields during spring and winter. Thus, wetlands and rice fields are important habitats for spot-billed ducks. Recently, spot-billed ducks were the third largest population of wintering ducks in Korea, but their numbers haves been declining continuously over the past decade (NIBR, 2020). This decrease in population is attributable to habitat changes (Shin et al., 2016b). Wetland conservation efforts are critical to ensure the survival of native species and maintain a steady domestic breeding population. Although this study analyzed the habitat and home range of spot-billed ducks in spring, further research is necessary. The findings of this study can serve as fundamental data to protect spot-billed ducks by managing two of their crucial springtime habitats, rice fields and wetlands.