• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.632-639
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• 2008

This paper deals with feeding site distribution aspect and seasonal distribution change of the wintering geese in Cheonsu bay and reclaimed area from October 2006 to March 2007. Geese were distributed mostly in agricultural land(rice field) during day time. According to the distribution map by maximum counts, observed geese of agricultural land were frequently distributed in large agricultural land. Especially, Geese were more used agricultural land near the reservoir where used as roosting site than the other sites. Diurnal feeding site of the geese were agricultural land near the reservoir with huge flock during early wintering season(October), but geese were used the agricultural land far from reservoir after mid wintering season(after January). The feeding flock size of Geese were decreased and feeding site was more far from the reservoir than in mid wintering season during late wintering season(March). Habitat use rate of the quadrat area where below 1km from the reservoir was most high in early wintering season. Contrary, habitat use rate where 2km far from the reservoir was shown lowest habitat use rate in early wintering season, but it was increased during mid wintering season(January) and decreased after mid wintering season. Habitat use rate of the agricultural land where 2km below and 1 km far from reservoir was shown middle rate, but it was increased until November and decreased after November. This result shown that feeding site preference of the wintering geese was affected by distance from roosting site(reservoir), and feeding site was changed as a food sources decreasing by stay time of geese flock.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.375-383
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• 2009

The aims of this study were wintering individuals, usage of foraging sites, potential food availability, daily activity and disturbance factors of White-naped Cranes Grus vipio on the wintering site, Han-river estuary, Goyang and Gimpo city, Korea. We want to provide basic data to conserve the cranes. Maxium population was identified 162 individuals at the middle of February in the river side and mud flat of this study area. Spring migration for breeding was started at the first week of March and finished for two weeks later. White-naped Cranes were used four feeding sites in winter; agricultural area in Hongdopyong, Yihwa-dong, Pyong-dong and Songpo-dong. Expected carrying capacity (ECC) was 334 days (121~909 days). White-naped Cranes departed from roosting site to feeding site at every morning for foraging. If they were disturbed by some factors at feeding sites, they moved to mud flat in the Han river to forage and take a rest. Daily activity was consisted of six category; feeding, alert, locomotion, preening, comfort, social and other behaviors. Feeding was the highest portion among behaviors in the wintering area. Feeding, alert, locomotion and preening in daily activities significantly differed among feeding sites. We watched total 348 times of disturbances in the wintering sites. Artificial disturbances were vehicles, humans, bicycles and motorcycles. Natural disturbances were noises, animals and others. Disturbances in all wintering sites were highest in Yihwa-dong (134 times) and followed by Hongdopyong (109 times), Songpo-dong (64 times) and then Pyong-dong (44 times). And artificial disturbances (228 times) were more than natural disturbances (120 times). Especially, vehicle was one of the most checked factor in the wintering area.

• Journal of Bio-Environment Control
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• v.17 no.1
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• pp.60-65
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• 2008

For autumn field cutting of Sedum sarmentosum, the effects of cutting site (distal, middle, and proximal) and planting method (space drill seeding, drill seeding, and broadcast seeding) on survival rate and growth characteristics were investigated at pre- and post-winter season. Plant height root length, stem number per plant, number of branch per plant, fresh weight of shoot, and dry weight of shoot were significantly superior in distal site at pre-wintering (40 days after cutting). At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in cutting of distal site showed a significant increasement compared to the cutting of proximal site. At pre-wintering (40 days after cutting), the growth in space drill seeding was well than that in drill seeding and broadcast seeding, and fresh weight and dry weight per $m^2$ in space drill seeding were high in order of space drill seeding, broadcast seeding, and drill seeding. At post-wintering (May 10th), stem number per plant, fresh weight and dry weight per $m^2$ in space drill seeding were significantly increased than those in drill seeding. Accordingly, the cutting using distal site of stem in autumn field cutting was desirable for the growth and shoot yield. The space drill seeding showed the highest yield potential among three seeding methods, but broadcast seeding was favorable in saving of labor, because the fresh weight of shoot in broadcast seeding was similar in the space drill seeding at post-wintering.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.9-14
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• 1997

Wintering behavior of mallards Anas platyrhynchos was studied from November 1995 to February 1996 at wintering habitats : Seosan reclaimed site, Oksan reservoir, and Kum river in Korea. The population of wintering mallards in maximum count was about 35, 000 at Sosan, 500 at Oksan and 1, 680 at Kum river, respectively. In Seosan area, mallards spent more time on water surface. In Kum river and Oksan reservoir, however, they spent more time in riversides. During the daylight hours, mallards spent more time in riversides and ground as the time passes by in the area. Behavioral patterns varied with habitat type, by days and months. Resting was a major time expenditure of mallards on water surface and riversides, and feeding occured occasionally on the ground. During the daytime, feeding and resting activities increased as time passed toward dusks However, time spendings for locmotion and comfort were decreased when it is close to the sun sets. Major disturbance factors within the habitats were identified the local traffics of humans, boats, aircrafts and motor vehicles. Among them, human was the most frequently affecting disturbance factor to the wintering mallards.

• Korean Journal of Environment and Ecology
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• v.32 no.5
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• pp.478-485
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• 2018

With the total population of 3,356 worldwide as of 2016, the black-faced spoonbill (Platalea minor) is designated as "endangered (EN)" species by IUCN. About 70% of population breeds on the uninhabited islands near the west coast of Korea and wintering area is Taiwan, China, Hong Kong, etc. However, there is few detail research in Korea and East Asia on black-faced spoonbill's long range migration and its habitat when migrating southward. We studied black-faced spoonbill's migration route, distribution, stopover, wintering sites, and timing of migration movements using a wild-tracker (WT-200, GPS-Mobile phone based telemetry, KoEco). We caught the black-faced spoonbills in the breeding sites (Gugi island, Bi island, Sangyeobawi, Chilsan island) in Korea in late June 2014. We attached the wild-tracker to 10 juvenile black-faced spoonbills. The tracking showed that the black-faced spoonbills started southward migration between late October and early November. The traveling distance to wintering site was maximum at 1,820 km, minimum at 746 km, the average at 1,201km. The maximum daily traveling distance was 1,479 km with an average of 782 km. The average days it took from breeding site to wintering site was 10 days (SD=10.7). The shortest duration was 2 days, and the longest duration was 34 days. Most individuals used 2-3 stopover sites between the breeding sites to the wintering sites and stayed almost 1-2 days (maximum 31 days). Stopover sites were wetlands such as rivers, streams, reservoir, and mud flat. The wintering sites were coastal areas (five individuals) in China, inland (one individual) in China, Taiwan (three individuals), and Japan (one individual). In conclusion, it is necessary to preserve the stopover sites and wintering site of the black-faced spoonbills through consultation and protection policy between countries and establish the systematic preservation measures and activity plans through continued moniting and additional studies.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.266-274
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• 2017

We surveyed the habitat use and food materials of the endangered Swan Goose (Anser cygnoides) during the wintering period at the Seocheon tidal flat. The bird wintered about six months from October 2014 to early April 2015 at the flat. They showed a remarkable change in choosing their feeding habitat and prey. They stayed entirely at sedge grass patches on Songrim tidal flat during the early wintering period (October), while after November they gradually moved to Janggu bay and used rice paddy fields as well as sedge patches on the tidal flats as their feeding site. The dietary analysis showed the sedge grass (Bolboschoenus sp., Cyperaceae) was the main dietary source during the entire wintering period. Interestingly, the proportion of Cyperaceae on feces decreased slightly over wintering time, while the proportion of Fabaceae increased relatively since November. These results suggest that the Swan Geese switched their habitat and food sources in response to the change of food availability. The Seocheon tidal flat area is the important wintering site for Swan Geese and sedge grass patches in the area need to be managed as the main feeding area for the wintering Swan Geese.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.681-692
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• 2015

It is well documented that physiological and nutritional condition of wintering birds is strongly related to migration success to breeding sites, and also breeding success. However, how abiotic factors during winter affect the migration and breeding successes still remains unclear. Thus, this study developed a dynamic-state-dependent model for wintering life-history to identify the potential impact on the life-history, success to breeding site and breeding success of wintering birds, which are related to temperature fluctuation, interspecific competition and human disturbance at the wintering sites. To find the best-fit-model, we referred to the existing research data on wintering ecology of Red-crowned cranes (Grus japonensis) in Cheolwon, Korea, which is well documented as a long-term wintering study. Our model predicted that the higher temperature fluctuation and a higher rate of human disturbance are negatively related to migration success to breeding sites and their fitness, ultimately breeding success via changing of proportion in resource allocation (for e. g., lower energy compensation or higher level of stress accumulation). Particularly, the rate of body mass compensation after arrival at wintering sites may be accelerated when there are less temperature fluctuations and a lower rate of human disturbance. In addition, the rate of interspecific competition sharing the wintering foraging sites is negatively related to the rate of body mass compensation. Consequently, we discussed the conservation strategies of wintering birds based on the outcomes of the model.

• Korean Journal of Environment and Ecology
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• v.23 no.3
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• pp.250-257
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• 2009

This study was conducted to investigate the habitat use of White-naped Cranes Grus vipio in Han river estuary during the wintering period from 2006 to 2008 (October$\sim$March). The average numbers of wintering White-naped Cranes were 106.6$\pm$21.7 (Mean$\pm$SD) individuals, and the highest number of 140 individuals were recorded in the early January, 2008. The wintering habitat use of White-naped Cranes between rice field and mudflat was not significantly different (Mann-Whitney test. p=0.40) during the wintering period. However, White-naped Cranes spent more time on the rice field in the early winter (p<0.01), and on the mudflat in the late winter(p<0.01). There was not a difference of the habitat use rate on middle winter. White-naped cranes used four different sites of rice field: Hongdopyoung, Pyoungdong, Ihwadong and Janghang rice fields. Among them, Hongdopyoung was the main foraging site. There was significant differences of habitat use ratio in the early and mid winter ((Kruskal-wallis test. p<0.01). White-naped Cranes used mudflat area from Gimpo Daegyo to Nusanri of Han river estuary. Especially, they preferred four sites from Gimpo Daegyo to Ilsan Daegyo more than the other sites. Habitat use rate of mud flats were significantly different among each site during the wintering period (Kruskal-wallis test. p<0.01)

• The Korean Journal of Ecology
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• v.28 no.1
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• pp.45-53
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• 2005

Urban stream is an important place supporting urban ecosystem. This study was carried out to clarify the role of Jungrangchun for wintering waterbirds in Seoul. We monitored the fluctuation of waterbirds population using our census data (1997/98 winter) and pervious census data (the Ministry of Environment and National Institute of Environmental Research $1999{\sim}2004$). Wintering behaviours of common teals (Anas crecca) were also observed to understand the habitat use of waterbirds in this area. As a result of this, Jungrangchun was an important place to support $3,004\sim8,237$ wintering birds, mainly dabbling ducks and diving ducks. The population of diving ducks showed high annual fluctuation whilst the population of dabbling ducks regularly used this area every year The maximum number of waterbirds foraged and rested in late January and late February. In daily use, the number of waterbirds increased on afternoon and rapidly increased after sunset. It is assumed that waterbirds used this area not only as a nocturnal feeding site but also daytime feeding site. Thus, this result suggest that Jungrangchun is important for not only the daily use but also the nocturnal use of wintering waterbirds. The number of diving ducks was increased with low temperature and high wind speed. Therefore, this area was also a shelter of diving ducks on chilly and windy day.

• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.176-187
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• 2015

In this study, we hypothesized that the size of wintering crane population would change due to the climate factors. We assumed that wintering population size would differ by climate values in January, which is the coldest period in year. Especially, White-naped cranes were able to choose wintering site between Cheorwon and other alternative place where snow coverage had low influence, differing from Red crowned cranes. For this reason, we predicted the population size of White-naped cranes would fluctuate according to the extent of snow coverage in Cheorwon. Therefore we used snow coverage data based on MODIS and climate data from KMA (Korea Meteorological Administration) that are generally used. We analyzed the crane's population size in Cheorwon in January from 2002 to 2014. The temperature in the Cheorwon increased from 2002 to wintering period in 2007~ 2008 and went down, showing the lowest temperature in 2011~ 2012. With this phenomenon, warmth index showed the similar pattern with temperature. Amount of newly accumulated snow (the amount of snow that fallen from 0:01 am to 11:29 pm in a day) was low after 2002, but rapidly increased in 2010~ 2011 and 2011~ 2012. The area of snow coverage rapidly declined from 2002 to 2005~ 2006 but suddenly expanded in wintering period in 2009~ 2010 and 2010~ 2011. Wintering population size of the White-naped cranes decreased as snow coverage area increased in January and the highest correlation was found between them, compared to the other climatic factors. However, the number of individuals of Red crowned cranes had little relationship with general climate factors including snow cover range. Therefore it seems that population size of the Red crowned crane varied by factors related with habitat selection such as secure roosting site and area of foraging place, not by climatic factors. In multiple regression analysis, wintering population of White-naped cranes showed significant relationship with logarithmic value of snow cover range and its period. Therefore, it suggests that the population size of the White-naped crane was affected by snow cover range n wintering period and this was because it was hard for them to find out rice grains which are their main food items, buried in snow cover. The population size variation in White-naped cranes was caused by some individuals which left Cheorwon for Izumi where snow cover had little influence on them. The wintering population in Izumi and Cheorwon had negative correlation, implying they were mutually related.