Author Archives: Lee Su Young

Ⅰ Summary

1. This project aims to provide clear evidence that Crested Honey Buzzards breed in Yeoncheon as a citizen science effort.

2. In 2025, a breeding pair inhabited an area near Gunnam Dam (about 700 meters away in a straight-line distance), and a fledged juvenile was later spotted within the same territory. This successfully confirms the breeding of the Crested Honey Buzzard in Yeoncheon.

– This pair was observed continuously staying within the territory from May 2 to September 22.

– From mid-July to mid-August, adults were seen transporting food.

– On the afternoon of August 18, the adult male circled slowly for about 15 minutes near the woods of the suspected nesting site while calling out. This is presumed to be encouraging and training their young as their fledging day approached.

– Just after noon on August 29, the parent birds flew directly over the suspected nesting woods, which appeared to stimulate their young to take their first flight.

– On September 4, a single juvenile with fresh plumage was observed circling slowly right near the presumed nesting site.

3. Additionally, 1–2 individuals appearing to be breeding adults were spotted near the Samicheon stream within the CCZ (Civilian Control Zone), and one presumed adult was recorded near Mount Godae. Putting these pieces together, it is likely that at least 3 pairs bred in Yeoncheon in 2025.

4. Aside from these local birds, 10 passage migrants migrating southward were counted from the same observation point, and a distinctive call was heard once near the Tomb of King Gyeongsun during the autumn migration.

5. In total, 15 to 17 Crested Honey Buzzards were recorded in Yeoncheon in 2025:

– 1 breeding pair and 1 fledged juvenile

– 2–3 presumed breeding adults

– 10–11 passage migrants passing through during the autumn migration period

Ⅱ Basic Information

1. Crested Honey Buzzards (Pernis ptilorhynchus): A large raptor of lowland and montane broadleaf and mixed forests, this species is well-known for its tendency to congregate in large flocks of up to thousands during migration. Resident populations inhabit tropical forests from lowlands up into montane areas. While showing considerable plumage variation throughout its range, the combination of an unusually small and slender head, long striped tail, broad wings, and well-striped underwings make this species fairly recognizable across a wide area. True to its name, this species is a raider of wasp and bee nests, although it prefers bee and wasp larvae over their honey. (source: eBird)

2. According to a Birds Korea Blog post ’Early July, Yeoncheon Imjin River Biosphere Reserve’ of July 20, 2025, “Four were seen in total at 2-3 locations (including one “new” summer site), including two seen together. Possibly three or more pairs breed in Yeoncheon.”

3. The surveys by Birds Korea have recorded this species since 2022 with annual observations in the area near Gunnam Dam since 2023.

Ⅲ. Observation and Analysis Methods

1. To provide clear evidence of the breeding Crested Honey Buzzards in Yeoncheon in 2025, efforts were made to secure as many photographs and videos as possible, primarily with a Nikon P1000 camera.

2. The area near Gunnam Dam, adjacent to the Civilian Control Zone, its surrounding mountain ridges along with the Imjin River, and Mount Gunja, provides reliable opportunities to spot Crested Honey Buzzards every summer.

3. This geographical advantage enabled consistent monitoring of the nearby resident Crested Honey Buzzards, mostly through backyard birding.

4. Across approximately 40 observation sessions from May 2 to October 18, a total of 747 data files (624 continuous images and 123 video files) were accumulated. In addition, there were 2 observation instances where no media data was secured.

5. Changes in plumage over time were tracked, despite the suboptimal quality of images and videos.

6. Despite potential errors in identifying individuals, only a single pair and their young were recorded within the observed breeding area during the breeding season.

7. The observation dates and captured images of the Crested Honey Buzzards in 2025 are provided in the attached PDF file.

Ⅳ Crested Honey Buzzards in Yeoncheon, 2025

1. Breeding Pair and Their Young

– The 2025 breeding schedule was estimated in the table below by applying an incubation period of approximately 30–35 days and a nestling period of about 40–45 days.

Breeding Stage	Period	Observation
Territory Establishment	Early May – Mid-June	May 2. Adult male first observed.
Incubation	Mid-June – Mid-July	June 19. Pair spotted together (Incubation shift?) July 6. Pair circling together
Nestling Period	Mid-July – Late August	July 17. Transporting a piece of wasp nest. July 21. Pair spotted together within the territory. July 24 & 28, August 11. Food transport. August 18. Adult male circled slowly for 15 minutes near the suspected nest site while continuously calling; presumed to be encouraging and educating the fledgling(s) to fledge. August 29. The pair flew together over the presumed nesting forest; likely encouraging the fledgling(s) to fledge.
Fledging	Around Latest August	September 4. A single fledgling with fresh plumage circled slowly near the presumed nest site.
Post-fledging Period	Through Mid-to-Late September	September 5, 20 & 22. Adult male (and also female?) observed within the territory.

– These adult birds were also observed in Samgot-ri and Hoengsan-ri in Jung-myeon, and Buksam-ri in Wangjing-myeon, which are each located 3 to 4 km away from the presumed nest site. However, because few observations were made outside these areas, it is difficult to clearly estimate the boundaries of their summer territory.

2. Other Individuals Indicating Breeding

– The adult on the left was observed twice within a short interval. It remains uncertain whether a single individual was observed twice or two separate individuals were observed once each. At this time, it was approximately one week before hatching for the breeding pair near Gunnam Dam, and the location is more than 13 kilometers away from their presumed nest site. Therefore, it appears likely to be another breeding pair.

– The adult on the right was being attacked by a Grey-faced Buzzard at a fairly low altitude along National Route 3. This location is over 17 kilometers away from the presumed nest site near the Gunnam Dam. Given that the buzzard crossed the road toward Godaesan Mountain to escape the attack, and that the Godaesan mountain range in Daegwang-ri is an area where Crested Honey Buzzards are observed in summer, it is possible that this bird used the vicinity of Godaesan Mountain as its summer breeding ground. However, few careful observations were made in the Godaesan area in 2025.

3. Passage Migrants

– A total of 10–11 migrating individuals were observed or heard in Yeoncheon during the autumn migration period from September 22 to October 18. Of these, five individuals were recorded within a single hour on October 8, between 08:21 and 09:31.

Ⅴ Conclusion

– Yeoncheon has been confirmed as a breeding ground for Crested Honey Buzzards, with breeding pairs inhabiting the area and fledged individuals being observed over recent years.

– This record from the 2025 breeding season confirms the breeding of Crested Honey Buzzards in Yeoncheon.

– In addition, the migration of Crested Honey Buzzards was also observed during the autumn migration period of raptors (predominantly Grey-faced Buzzards and Eastern Buzzards).

[download] EngCHBuzzardRecord2025 (PDF)