• Journal of Ecology and Environment
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• v.30 no.2
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• pp.121-126
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• 2007

We monitored gold-spotted pond frog (Rana chosenica) populations near the Korea National University of Education in Chungbuk, Korea, from 19 May to 8 August, 2006 to examine the spatial distribution of populations in local areas and to investigate patterns of migration of adult gold-spotted pond frogs from terrestrial hibernation sites to breeding sites, We captured individuals from the largest population using a drift fence with 22 pitfall traps surrounding the breeding site. A total of 22 individuals (19 males and 3 females) were captured between 23 May and 15 June. No peak in breeding migration was detected, but the onset of the breeding migration may correspond with increased humidity. Male body weights were negatively correlated with sampling dates. Seven of 22 individuals were captured at the 4th pitfall trap, which was placed between two culverts. The capture rate per pitfall trap was higher in traps close to the rice field banks (1.44, traps $1{\sim}9$) than in traps facing hilly land (0.33, traps $13{\sim}18$). Comparative data from the Korean frog (Rana coreana), a sympatric species in the study area, were also collected and compared with those of the gold-spotted pond frog.

• Korean Journal of Environment and Ecology
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• v.22 no.1
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• pp.59-65
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• 2008

This study is mainly focused on the mating of 9 couples of Eagle Owl Bubo bubo habitating in Paju, Ganghwa Island, Icheon, Sihwa Lake, Chungju. For this study, from 2005 to 2007, regular filming and mornitoring for the breeding ecology and copulation behavior of 9 couples of Eagle Owl in the nest and near area had been done. Clutches ranged in size from one to four eggs but averaged 2.27 eggs(n=15), hatching success rate was 71 %(n=34) and fledgling success rate was 83%(n=23). Through the filming and mornitoring, it was found that Eagle Owl continued to copulate each other even after hatching and kept its copulation until the chicks left their nest($7\sim8$ weeks after hatching). This copulation behaviour without fertilization seems to be done for confirming, maintaining and strengthening of pair-bond by the necessity of both male and female, and to aim at stable breeding of their chicks.

• 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.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.237-243
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• 2005

To study entering and exiting routes of male and female Hynobius leechii to a breeding site and staying time of them within the breeding site, we monitored a breeding population located in the research forests of Kangwon National University. The breeding site was surrounded by a drift fence associated with nine pitfall traps. The breeding season of this population was about one month, from 16 March to 13 April, 2005. Breeding males arrived earlier at the breeding pond than females did. The operational sex ratio (OSR), defined as the ratio of males to females which are ready to mate, over a breeding season was female-biased as 0.67 male vs 1 female (57 males vs 87 females), but daily OSRs, OSR in a particular day, within the breeding pond were male-biased with $1.36\sim7.5$ male vs f female in six days out of seven investigated days. While breeding males stayed in the breeding pond for about 11 days, breeding females left the pond as soon as they completed oviposition. However, the females stayed at terrestrial areas near the pond for about seven days before completely leaving the breeding site. Entering and exiting routes to the breeding site were different between males and females, and between ovulated and oviposited females. Both males and females arrived earlier at the breeding site stayed longer within the site. Males stayed longer within the breeding site lost more body weight.

• Korean Journal of Ecology and Environment
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• v.51 no.2
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• pp.184-191
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• 2018

During the breeding season, some Eurasian Oystercatchers (Haematopus ostralegus osculans) in Yubu Island foraged in the open mudflat area nearby the breeding ground, instead of the tide water line area, main feeding site throughout the year. We found significant differences in foraging behavior and prey species diversity between the two different feeding site types. Even though the birds took more steps for most probably searching preys, their feeding success was much lower in the open mudflat area than the tide water line area. The multiple peck and boring methods were more frequently adopted to catch polychaetes on the open mudflat area, whereas the single peck method was dominant and gastropods and bivalves were main preys in the tide water line area. This study suggests that the bird shows flexible foraging strategy of shifting feeding site, foraging behavior and preys for better reproductive success.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.3
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• pp.154-164
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• 2022

Understanding temporal variations in wildlife populations is a prerequisite for conservation planning of wide-ranging species such as tigers (Panthera tigris). We determined the temporal variation in abundance, population growth, and sex ratios at different age and sex stages for a tiger population in Ranthambhore Tiger Reserve, India from November 2007 to February 2011 using motion-sensing cameras. We identified 19 male and 21 female tigers from stripe patterns during 16,110 trap nights within an area covering 233 km². The annual abundance of the population varied from 34.9 (mean)±3.8 (SE) to 23.9±1.5, with a declining trend in the mean annual change of abundance (-12%). The density of adult females remained stable across the study duration, but the densities of adult males and non-breeding tigers fluctuated. The sex ratio was female-biased (0.58 males/female) for breeding tigers and male-biased (1.74 males/female) for non-breeding tigers. Our results reinforce the importance of long-term studies for monitoring the naturally occurring processes in populations to develop population indicators and identify reliable baseline information for conservation and management planning of populations.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.595-597
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• 2008

We photographed a nest of Bubo bubo kiautschensis in Icheon, Gyeonggi-do, which had laid 3 eggs and was incubating the eggs. Although 2 chicks were hatched from the 2 eggs, one of them disappeared and the other of them died in March 8, 2007. After that, the parent bird ate the dead chick and left the nest abandoning breeding the next day.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.47-53
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• 1996

Effects of group breeding of herons on pine community were studied at Pomaeri, in Yangyang, Kangwon Province, Korea. This site has been protected as a Natural Monument (No. 229) since 1970. Herons have used this habitat as a breeding site from] anuary to October every year. In 1995, more than 500 herons were observed in this habitat. Many big pine trees are dying or already dead due to group inhabitation of herons, and no pine saplings were found at forest floor in this habitat. Nutrient contents of soil in this habitat were much higher than those in control plot. This must be due to the addition of feces from herons and of thin twigs and other organic materials from the canopy and bird nests. Species composition of herb layer in this habitat was quite different from that in control plot. Breeding site was dominated by Humulus japonicus. Persiearia perJohata, Persicaria thunbergii. and Commelina communis. which are indicator species of soil eutrophication.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.207-211
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• 2020

Adult land crabs generally live on land while their larvae live in the sea. In the case of Sesarma haematoche, female crabs migrate from land to sea to release the larvae at the high tide of syzygy night. Artificial structures along coastal areas are being obstacles for the migration of land crabs and causing synchronized roadkills on coastal roads during breeding migration. In this research, we compared the sex ratios of crab populations in coastal areas with coastal roads and uninhabited island areas with no road. The proportion of females in inland habitats with coastal roads was significantly smaller than island habitats. In particular, females are exposed to the risk of annually repeated roadkills, and the proportion of females decreases rapidly with their growth. If this tendency is general for land crab populations in the coastal areas with roads, significant road mortality of female land crabs during breeding migration can lead to severe population decline in coastal areas. Therefore, it is necessary to take an action to save land crabs crossing coastal roads.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.287-293
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• 2011

Analysing companion species from unrelated taxa concentrated so far mainly on identifying biosurrogacy in terms of conservation biology. No study has investigated companion bird and plant species to predict breeding and migrant habitats of a bird genus. In this study we recorded and analysed companion bird and plant species of the breeding bird Cyprus Wheatear Oenanthe cypriaca and four migranting Oenanthe species on Cyprus. We found characteristic companion species in Cyprus Wheatear's, Wheatear migrant's and in control habitats where no Wheatears were present. We show that plant and bird companion species can be used as discriminating factors to predict breeding and migrant habitats of the genus Oenanthe on Cyprus. Furthermore, habitat preferences of Cyprus Wheatear's companion species indicate bushy and vegetation rich habitats avoiding woodland on the one hand and managed farmland on the other hand. In comparison, migrant Wheatear and control habitats were characterised by companion species pointing to a high openness. These results support former habitat descriptions of Cyprus Wheatear and migrant Wheatears. In more general, this study shows that companion species from unrelated taxa can be used to predict breeding and migrant habitats of a bird genus.