The current study explored the movement characteristics of 14 migratory bird species that wintered in the Republic of Korea between 2014 and 2020. The migratory bird movement information was obtained via a global positioning system operated by the Korean government. The velocity of movement, number of clusters, and size of clusters of the migratory bird species during their movement from their departing country to the Republic of Korea were estimated by applying a method based on density-based spatial clustering of applications with noise. The average movement velocity of pintails (Anas acuta) that departed from China or Russia was 32.77 km/h, the highest velocity among those measured for the 14 migratory bird species. The average number of clusters for cinereous vultures (Aegypius monachus) was 43.00, which was the largest cluster number observed. However, herring gulls (Larus argentatus) had the largest cluster area with an average cluster radius of 27.43 km while wintering in the Republic of Korea. The findings of the current study could be useful in increasing the effectiveness of the Korean national highly pathogenic avian influenza (HPAI) surveillance program. The human and material resources of the HPAI surveillance could be allocated after considering the results of this study, revealing the movement characteristics of wintering migratory birds in Korea. The HPAI surveillance program should include fecal or swab sampling to detect the HPAI virus in both pintail and bean goose (Anser faballis) wintering sites. Sampling of those sites should have a higher priority than that for other migratory bird wintering sites since pintail and bean goose move faster and form larger clusters.

Abstract
INTRODUCTION
MATERIALS AND METHODS
    Migratory birds’ movement data
    Estimating migratory birds’ movement velocity
    Clustering migratory birds’ movement
RESULTS
DISCUSSION
CONCLUSION
REFERENCES

• Son-Il Pak(College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University) Corresponding Author.
• Ho-Sung Lee(Animal and Plant Quarantine Agency)
• Yeon-Sook Kwak(KWARE)
• Kug-Lyoul Jang(KWARE)
• Eu-Tteum Kim(College of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University)