• Title/Summary/Keyword: Tehan

Search Result 8, Processing Time 0.026 seconds

A Study on the Home-Range and Habitat Use of Spot-Billed Duck (Anas poecilorhyncha) in Spring

  • Kim, Soon-Sik;Kang, Tehan;Kim, Dal-Ho;Han, Seung-Woo;Lee, Seung-Yeon;Cho, Haejin
    • Proceedings of the National Institute of Ecology of the Republic of Korea
    • /
    • v.3 no.4
    • /
    • pp.199-203
    • /
    • 2022
  • The spring home range and habitat use of the spot-billed duck in Korea were studied using GPS-mobile phone-based telemetry (WT-300). The study areas were Anseong-si, Seosan-si, Nonsan-si, and Sejong-si. Analysis was performed using minimum convex polygon (MCP) and kernel density estimation (KDE) spot-billed ducks had an average home range of 70.28 km2 (standard deviation [SD]=84.50, n=6), and a core habitat (50%) 2.66 km2 (SD=2.60, n=6), according to MCP and KDE, respectively. Wetlands (41.5%) and rice fields (35.7%) were highly used as habitats. The rice field use rate was high during the day, and the wetland utilization rate was high at night. Rice fields and wetlands were the primary habitats in spring.

Characteristics of Wintering Habitat use by Black-tailed Gulls (Larus crassirostris) on the West Coast of Korea

  • Tehan Kang;Soon Sik Kim;Daehan Cho;Tae Wan Kim;Woon Kee Paek;Si-Wan Lee
    • Proceedings of the National Institute of Ecology of the Republic of Korea
    • /
    • v.5 no.2
    • /
    • pp.37-42
    • /
    • 2024
  • This study used a GPS tracker to determine characteristics of wintering habitat use by black-tailed gulls on the west coast of Korea. Results of this study showed a southward movement in December and a northward movement in March. The wintering habitat was confirmed to include the southwest coastal island area (Group 1), the inland coastal area (Group 2), and China (Group 3). The wintering home range was the narrowest in October and the widest in December. Home range of Group 1 was increased from November, showing the maximum in December, decreased in February, and then tended to increase again in March. Group 2 showed the widest home range in November and a narrow range of home range from December. Home range of Group 3 showed a mixed pattern of group 1 and group 2. The flight rate was the lowest in January and the highest in March. Day and night flight rates showed significant differences by month. This study identified wintering characteristics of the West Coast population of black-tailed gulls on the West Coast, including their wintering areas, migration periods, and use patterns. These wintering characteristics of black-tailed gull in the west coast area are thought to be affected by environmental factors (such as food resources and fishing activities) and geographical characteristics of the West Coast where many islands are distributed.

Prevalence of Cigarette Smoking and Associated Factors among Male Citizens in Tehran, Iran

  • Kassani, Aziz;Baghbanian, Abdolvahab;Menati, Rostam;Hassanzadeh, Jafar;Asadi-Lari, Mohsen;Menati, Walieh
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.3
    • /
    • pp.1473-1478
    • /
    • 2016
  • Background: Cigarette smoking is as the leading cause of cancer mortality and other chronic diseases in males worldwide. The prevalence of cigarette smoking is different across and within countries by age, education level, occupation, and so on. This study aimed to determine the prevalence of cigarette smoking and its relationship with individuals' demographic factors and BMI in adolescent men living in Tehran, Iran. Materials and Methods: This study involved secondary analysis of the 'Urban Health Equity Assessment and Response Tool-2' survey conducted in Tehran, Iran, among men aged 20+, 2011-2012. Using a multistage sampling method, 45,990 men were included in the study. The cigarette smoking status, BMI and demographic factors measured through a self-administered questionnaire. Chi-square, t-test, and logistic regression model were used to examine the relationships between the independents variables and cigarette smoking behavior, using SPSS software version 21. Results: In the total of 45,990 men, the overall prevalence of cigarette smoking was 14.6% (CI 95%: 14.29-14.94). Age (OR=0.96; CI 95%:0.94-0.98), house ownership (OR=0.68; CI 95%: 0.64-0.72), job status (OR=0.60; CI 95%: 0.46-0.86), marital status (OR=0.42; CI 95%: 0.39-0.47) and educational levels (OR=0.50; CI95%: 0.45-0.54) were associated with the prevalence of cigarette smoking. However, associations with BMI, family size, residency years, and district were not statistically significant. Conclusions: Given the relatively high prevalence of cigarette smoking in the study population, policy interventions are required to address this major public health issue, with a focus on the population demographic influences.

Flight behavior of cinereous vultures (Aegypius monachus) in the wintering season in Korea (한국에 월동하는 독수리의 비행 행동 특성 분석)

  • Kang, Tehan;Lee, Sangbo;Lee, Hansoo;Peak, Woon-Kee;Yu, Jae Pyoung;Jin, Seon-Deok
    • Korean Journal of Environmental Biology
    • /
    • v.37 no.4
    • /
    • pp.579-584
    • /
    • 2019
  • The flight characteristics of 11 cinereous vultures (Aegypius monachus) were analyzed by a global positioning system (GPS) tracker(WT-300; KoEco, Inc.). The wintering period in Korea averaged 131 days (SD=17.4) and the average flight rate was 19.6%. The flight altitude was below 100 m for 21.6% of the flight, 101-200 m for 25.3%, 201-300 m for 19.0%, and below 300 m for 65.9%. There was a positive correlation (r=0.929) between the hourly flight rate and altitude. The predominant monthly flight altitude was 101-200 m (p<0.05). The wintering cinereous vultures lowered their flight rate and flew at an altitude of less than 300 m. This is thought to be an efficient way to find food through social interaction.

Comparison of potential food resources by barn swallow habitat type (제비 서식지 유형에 따른 잠재적 먹이원 비교)

  • Sung Hoon Choi;Seon-Deok Jin;Tehan Kang;Eun-Jung Kim;Joohyuk Yoon;Hong-Shik Oh
    • Korean Journal of Environmental Biology
    • /
    • v.40 no.4
    • /
    • pp.604-614
    • /
    • 2022
  • This study analyzed habitat status of barn swallows within 800 m and changes in potential food resource occurrence for 63 nests (Seocheon 23, Sejong 40) where barn swallows breeding was confirmed in Seocheon and Sejong in 2019 and 2020. As a result of checking habitat compositions of barn swallows in the study area, Sejong showed more varieties of habitat types than Seocheon, showing a larger number of dominant groups. Such large number of dominant groups was found to be an advantageous habitat factor for producing flying insects as potential food resources for barn swallows. As for the production of potential food resources, Seocheon had the highest production in dwelling and stream and Sejong had the highest production in the stream. The production of potential food resources differed in production season by habitat type. This study analyzed compositions of the habitat around the breeding site of swallows. It provides basic data necessary for protecting barn swallow habitats by comparing the production timing and production volume of potential food resources occurring in the habitat.

Movements and Home-range of Mallards by GPS-Mobile based Telementary (WT-200) in Korea (야생동물위치추적기(WT-200)를 이용한 청둥오리의 이동거리 및 행동권 연구)

  • Kang, Tehan;Kim, Dal-Ho;Cho, Hae-Jin;Shin, Young-Un;Lee, Hansoo;Suh, Jae-Hwa;Hwang, Jongkyung
    • Korean Journal of Environment and Ecology
    • /
    • v.28 no.6
    • /
    • pp.642-649
    • /
    • 2014
  • Mallard (Anas platyrhynchos) is the abundant winter visitor in South Korea. Mallard migrates long distances between Russian Siberia and Korea. This species prefers a rice paddy area as their winter habitat. We captured birds using cannon-net, and attached the GPS-Mobile phone based Telemetry(WT-200) on Seven Mallards in the winter of 2011~2013. We were monitored wintering home-range and movement distance. We analyzed the tracking location data using ArcGIS 9.0 and calculated Kernel Density Estimation (KDE) and Minimum Convex Polygon (MCP). The average home-range in the wintering ground by MCP was $118.8km^2$(SD=70.1, n=7)and the maximum home-rang was $221.8km^2$ and the minimum was $27.7km^2$. Extents of home-range by KDE were $60.0km^2$(KDE 90%), $23.0km^2$(KDE 70%) and $11.6km^2$(KDE 50%). Mallard moved an average of 19.4 km from start site(attach to WT-200 site), maximum moved was 33.2 km and minimum moved was 9.4 km. The average distance of 0.8 km between GPS fixed point(range 0.2~1.6 km), maximum moved was 19.7 km. Mallard moved a very short distance in wintering season and showed a very high water-dependent trends in wintering site.

Some effects of environmental changes on Sihwa Reclaimed Land on the inhabit of Spot-billed Ducks (간척지의 환경변화가 흰뺨검둥오리 서식에 미치는 영향)

  • Jin, Seon-Deok;Paik, In Hwan;Park, Chi Young;Choi, Seong Hoon;Yu, Jae Pyeong;Paek, Woon Kee;Kang, Tehan
    • Korean Journal of Ornithology
    • /
    • v.25 no.2
    • /
    • pp.87-93
    • /
    • 2018
  • In order to investigate the changes in the population of Spot-billed ducks due to changes in reclaimed land, we conducted a monthly survey from January 2008 to December 2014 at the Shihwa Lake. The average number of Spot-billed ducks was 12,204 individuals. The average population was decreased. The yearly index of fluctuation (Fi) was the highest at 2.16 in 2010. TRIM(TRends and Indices for Monitoring data) showed a steep decline in winter and a moderate decrease tendency in autumn and spring. However, in the summer season, it showed an moderate increasing tendency. The main habitat were Northland reclaimed land, agricultural land and wetland area, Tando waterway, Shihwa artificial wetland in upstream. The correlation between the number of Spot-billed ducks and the temperature was negatively correlated in spring, summer, autumn. However, winter was showed positive correlation. Therefore, it affects the community of Spot-billed ducks due to environmental changes of reclaimed land. In future, effective management is needed to prepare alternative habitat based on basic data like this study for the conservation and management of Spot-billed ducks during reclamation construction.

Predicting the Goshawk's habitat area using Species Distribution Modeling: Case Study area Chungcheongbuk-do, South Korea (종분포모형을 이용한 참매의 서식지 예측 -충청북도를 대상으로-)

  • Cho, Hae-Jin;Kim, Dal-Ho;Shin, Man-Seok;Kang, Tehan;Lee, Myungwoo
    • Korean Journal of Environment and Ecology
    • /
    • v.29 no.3
    • /
    • pp.333-343
    • /
    • 2015
  • This research aims at identifying the goshawk's possible and replaceable breeding ground by using the MaxEnt prediction model which has so far been insufficiently used in Korea, and providing evidence to expand possible protection areas for the goshawk's breeding for the future. The field research identified 10 goshawk's nests, and 23 appearance points confirmed during the 3rd round of environmental research were used for analysis. 4 geomorphic, 3 environmental, 7 distance, and 9 weather factors were used as model variables. The final environmental variables were selected through non-parametric verification between appearance and non-appearance coordinates identified by random sampling. The final predictive model (MaxEnt) was structured using 10 factors related to breeding ground and 7 factors related to appearance area selected by statistics verification. According to the results of the study, the factor that affected breeding point structure model the most was temperature seasonality, followed by distance from mixforest, density-class on the forest map and relief energy. The factor that affected appearance point structure model the most was temperature seasonality, followed by distance from rivers and ponds, distance from agricultural land and gradient. The nature of the goshawk's breeding environment and habit to breed inside forests were reflected in this modeling that targets breeding points. The northern central area which is about $189.5 km^2$(2.55 %) is expected to be suitable breeding ground. Large cities such as Cheongju and Chungju are located in the southern part of Chungcheongbuk-do whereas the northern part of Chungcheongbuk-do has evenly distributed forests and farmlands, which helps goshawks have a scope of influence and food source to breed. Appearance point modeling predicted an area of $3,071 km^2$(41.38 %) showing a wider ranging habitat than that of the breeding point modeling due to some limitations such as limited moving observation and non-consideration of seasonal changes. When targeting the breeding points, a specific predictive area can be deduced but it is difficult to check the points of nests and it is impossible to reflect the goshawk's behavioral area. On the other hand, when targeting appearance points, a wider ranging area can be covered but it is less accurate compared to predictive breeding point since simple movements and constant use status are not reflected. However, with these results, the goshawk's habitat can be predicted with reasonable accuracy. In particular, it is necessary to apply precise predictive breeding area data based on habitat modeling results when enforcing an environmental evaluation or establishing a development plan.