• Journal of Environmental Science International
• /
• v.32 no.8
• /
• pp.533-542
• /
• 2023

Understanding the regional distribution of swans in the lower Nakdong River area is also important for the continuous habitat of swans according to changes in the surrounding environment of the area. This study was conducted to understand the regional distribution aspect of swans (Cygnus spp.) downstream of the Nakdong River, Republic of Korea, from October 2013 to September 2018. In the estuary, a small ship was used to move along a certain route and observe it with the naked eye or binoculars, and in the land area, Line transect census and Point census method were conducted in parallel. During this period, two species and 34,647 individuals of swans were observed, including 34,356 Whooper Swans (Cygnus cygnus) and 291 Tundra Swans (Cygnus columbianus). The average number of individuals observed in 15 different areas was 1172, 103, 214, 1825, 1850, 13, 318, 1, 0, 1, 11, 21, 5, 0, and 239 respectively. The total average of the number of individuals in these areas was 384.76. The numbers differed significantly among the survey areas (Kruskal-Wallis test, X2=4349.01, P < 0.001). Particularly, the numbers were larger in Eulsukdo, Lower Eulsukdo, and Daemadeung than in the other regions. In conclusion, as long-term survey data, it can be used as basic data to analyze the distribution of swans due to environmental changes caused by the development of the Nakdong River, predict changes in the habitat status of migratory birds, and prepare measures necessary for preservation.

• Journal of Environmental Science International
• /
• v.32 no.7
• /
• pp.493-502
• /
• 2023

This study was conducted to understand the regional distribution characteristics of swans(Cygnus spp.) in downstream of t he Nakdong River , R.O.Korea from October 2008 to September 2013. During this period, a total of two species and 37,518 ind ividuals of Swans(Cygnus spp.) were observed, including 31,596 Whooper Swans(Cygnus cygnus) and 5,922 Tundra Swans (Cygnus columbianus), respectively. The average number of individuals observed in fifteen different areas was 2255.33 in D aemadeung(A), 143.50 in Jangja·Sinjado(B), 304.00 in Sajado·Doyodeung(C), 1928.00 in Lower Ulsukdo(D), 1392.67 in Ulsu kdo(E), 50.17 in Ilwoongdo(F), 91.17 in Yeommak(G), 5.17 in Maekdogang(H), 0.00 in Pyeonggangcheon(I), 0.00 in Lower Noksan sluice(J), 2.83 in Upper Noksan sluice(K), 6.17 in Jomangang·Doonchido(L), 4.50 in Chideung(M), 0.83 in Joongsado (N)and 66.17 in Daejeo sluice(O). The total average of these fifteen areas was 480.81. There was a significant difference am ong the survey areas (Kruskal-Wallis test, 𝒳²=4055.68, P<0.001). In particular, the observed numbers were larger in Dae madeung, Lower Ulsukdo and Ulsukdo than in the other regions.

• Korean Journal of Heritage: History & Science
• /
• v.57 no.1
• /
• pp.162-178
• /
• 2024

Swans are representative migratory birds that spend winter in East Asia, and have long been considered rare birds. In particular, they were regarded as king of Japan. The process of designating a natural monument in Hapcheon Swan Sanctuary is an interesting story. In this study, the designation and release process of Hapcheon Swan Sancturay ((Bakgok-ji, Yongju-myeon 龍州面 朴谷池), (Jeongyang-ji, Daeyang-myeon 大陽面 正陽池), Gaho, Cheongdeok-myeon 淸德面 嘉湖)) Natural Monument, was examined. These places were designated as a natural monument on August 27, 1934, during the Japanese colonial period, and was lifted on August 14, 1973, after the Cultural Protection Act was enacted after liberation. From the beginning of the new year in 1929, the Japanese Government-General of Korea (朝鮮總督府) decided to capture swans alive to give to the king of Japan. An official of the Japanese Government-General of Korea (統監) decided to offer swans to the king during his New Year's greeting visit. The department in charge of capturing swans was the Gyeongsangnam-do Provincial Police Department, and the execution was the police station of each county (郡). The reason is believed to be that it is easy to forcibly mobilize, control, or urge people, and the capture activity had to be completed as soon as possible. A total of three swans were captured in Hapcheon-gun from January 12 to 14, 1929. At that time, various newspapers published related information. Based on these facts and experiences, it is estimated that the Hapcheon area was selected when designating a natural monument in 1934. Hapcheon Swan Sancturay, Natural Monument lost its function due to excessive human interference of various developments, illegal capture, and use of poison to catch swans. Their number has also significantly decreased. It was thus removed from the natural monument in 1973. One of the three swan sanctuaries (Gaho 嘉湖) has been completely reclaimed, one (Bakgok-ji 朴谷池) has almost no migratory birds due to the conversion of wetlands, and one (Jeongyang-ji 正陽池) has swans flying back. In the case of Jeongyangji (正陽池), It is an encouraging sign that many swans fly as the surrounding environment and growing conditions change. This phenomenon is interpreted to mean that nature and climate are recovering and healing.

• Korean Journal of Environment and Ecology
• /
• v.30 no.5
• /
• pp.848-856
• /
• 2016

The purpose of this study is to determine the impact on settlement pattern of wintering swans by distribution of rapidly spreading lotus in Junam reservoir. When we investigated the relationship between the spreading lotus and population variation of the wintering swans in all around Nakdong-river estuary, the spreading lotus did not affect the number of swans in Junam reservoir. The occupation ratio of lotus distribution continuously increased from 13.2%(2013) to 19.0%(2014). Before we begin with the investigation, we compared two particular groups: inside of lotus community and far (>100 m) water area from the border of lotus community. At the first survey(2013.12.17), we observed 3.1 times more swan population in the inside, comparing with far water area. The third(2014.01.29.) and fourth(2014.12.03) inquiries also showed respectively 5.5 and 7.5 times higher swan population in the inside and near water area. The second observation was conducted during visitors were increased so these phenomenon was not observed. This result might be explained as the similar environmental condition of habitate for swan and lotus such as less than 1 m water depth. However, we considered that lotus and swan were not relation of conflict due to increasing both lotus community and swan population at the same time. According to the observation that inhabitation density of wintering swans is significantly high in near lotus communities area, at least spread of lotus did not negatively affect the wintering swans.

• Korean Journal of Ecology and Environment
• /
• v.51 no.4
• /
• pp.365-372
• /
• 2018

The Wintering Waterbird Census of Korea was started in 1999 and monitors 200 major migratory sites in South Korea. Waterfowl counts have been undertaken for more than 20 years since; however, a limited number of studies have analyzed the temporal patterns of waterfowl population. In this study, we analyzed population size changes of wintering whooper swan (Cygnus cygnus) at 112 monitoring sites from 2001 to 2018. The average number of whooper swans was $4,296{\pm}42.66$ and there was a trend for an increase in population size across the survey period. We found that the population in the Nakdong River Estuary, one of the major wintering sites over 18 years (26.22% of the national population), had rapidly decreased (-0.77% per year). Conversely, the whooper swan population in the Junam Reservoir and Sihwa Lake increased (+1.64%, +0.54% per year, respectively). Estuaries showed the highest dominance of whooper swans among the five different habitat types, accounting for 32.13% of the population. Reservoir/lakes had 30.60% of the total population and reclaimed lakes(18.24%), river (13.11%), and coast (5.93%) followed. The annual distribution of the whooper swan population in South Korea has been affected by various habitat conditions resulting from human activities and urbanization. To better understand the complex factors that can cause rapid changes in wintering waterfowl populations, it is necessary to integrate the data from the bird census program with environmental conditions to conduct in-depth pattern analyses over longer time periods.

• Proceedings of the Zoological Society Korea Conference
• /
• 2003.08a
• /
• pp.148.3-148
• /
• 2003

No Abstract, See Full Text

• Journal of Multimedia Information System
• /
• v.5 no.2
• /
• pp.91-98
• /
• 2018

We devised a bird-borne transceiver unit for S-band packet radio communications based on the CC2500 transceiver, a device manufactured by Texas Instruments (TI). Our assessments determined the optimal parameters needed to achieve successful bird-to-center communication over a distance of 18 km and bird-to-bird communication over a distance of 200 m. These parameters included optimal modulation methods, transmission rates, and antennas. We equipped the transceiver unit with a modified dipole antenna (collinear antenna), which we tested in a 10 m anechoic chamber. Our experimental assessments and circuit design review identified the following parameters: 2FSK modulation method; 14.28 kHz frequency shift; 101.56 kHz IF reception bandwidth; and Manchester encoding (+). Our assessments showed bird-to-bird communications could be achieved over a distance of 200 m assuming MSK, FEC (+), and 500 kbps. Following tests by an official body, we obtained 28 sets of a type approval license for 2.4 GHz. In cooperation with the Yamashina Institute for Ornithology, we attempted to tag and release six or more swans. This unit gives us the ability to obtain vital data on swans. We expect this data to provide significant benefits, including clues on improving screening for infected individuals.

• Korean Journal of Environment and Ecology
• /
• v.34 no.3
• /
• pp.191-197
• /
• 2020

The purpose of this was to examine the differences of large whopper swan (Cygnus cygnus) in wintering habitat preference among bridge sections of the lower Nakdong River of the Nakdong River Estuary, the largest whopper swan's wintering habitat in Korea. This species is designated and protected as Natural Monument in Korea. The survey was conducted in six time-series during the 2018~2019 wintering season, and it found up to 500 whopper swans were wintering in the lower Nakdong River. For the survey, a seven sections were set up based on the bridges across the river. Whopper swans were rarely observed in five narrow sections where the distance between bridges was less than 2 km. The stable population of the whopper swan was observed only in two broader sections where the distance between bridges was is over 4 km. As these sections were relatively little affected by artificial interference, the distance from the mouth of the Nakdong River was not a factor. Securing a stable space is considered as one of the most important factors for wintering of whopper swans, which are an endangered species. The survey results indicate that the distance between bridges should be at least 4 km to secure the whopper swan's stable habitat. These results are expected to be a reference to the development or restoration of the river ecosystems, especially bridge construction.

• Proceedings of the Korean Society of Veterinary Pathology Conference
• /
• 2005.11a
• /
• pp.51.1-52
• /
• 2005

• Korean Journal of Ecology and Environment
• /
• v.55 no.4
• /
• pp.406-414
• /
• 2022

Bolboschoenus planiculmis has been acknowledged as a key species in whooper swans (Cygnus cygnus) habitat by providing food for this migratory waterfowl. B. planiculmis wetlands are being degraded by water shortages and salinization caused by anthropogenic activities and climate changes. In 2004, the distribution of B. planiculmis in the tidal flats of the Nakdong Estuary was 2,475,568 m², and in 2021, the distribution area was 798,731 m², which decreased by 32.3%. In order to restore the degraded B. planiculmis wetlands, shoot transplantation and seed sowing were tentatively used in three places with different salinity and water levels. The average density per unit area in September at the optimal growth period after planting were A (fresh water level 50 cm) 58±15.65 m^-2, B (brackish water level 0~5 cm) 188±63.83 m^-2, C (brackish water level 0 cm or less) 188±45.13 m^-2. The tubers were observed as A 0 g dw m^-2, B 25.32±2.94 g dw m^-2, and C 13.39±0.91 g dw m^-2. Tubers were distributed in the soil, with only 3.0% at the 10~20 cm depth but 97.0% at the 0~10 cm depth. In contrast, the germination rate of B. planiculmis seeds was observed to be 0%. Results of this study provide technical support for the restoration of B. planiculmis wetland and the improvement in the quality of whooper swans habitat.