• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.50-55
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• 2009

To understand the status of the migrating Oriental Honey Buzzard(Pernis ptilorhynchus) in Korea, we carried out a preliminary study on the number and local movements of the Honey Buzzard from September 2005 to October 2007 at Hongdo Island, Jeonnam Province, Korea. A total of 702 Honey Buzzards in 2005, 404 individuals in 2006, and 659 individuals in 2007 were recorded during the fall migration season, but during the spring migration season only two and eight birds were observed in 2006 and 2007 respectively. The migrating Honey Buzzard showed peak numbers from 20 September to 5 October at the study site. According to observation of arrival time of538 Honey Buzzard in October 2007, a total of 2l6 birds(40.l %) were passing over Hongdo Island between 7:00 AM to 8:00 AM, rising skyward on columns of warm air. This suggests the use of thermal currents and avoidance of nocturnal movement for crossing water. They preferred moderate winds(<5 m/s in speed) from northwest, but the migrating number apparently decreased in case of strong winds (${\geqq}5 m/s$). This suggests that wind speed and direction are important environmental factors for migration of the Oriental Honey Buzzard. At present, it is unclear which breeding population(from north-eastern China or Japan) passes over Hongdo Island. Moreover, it is difficult to prove migration route and to understand migratory behaviors of the Oriental Honey Buzzard in Korea. To prove the breeding sites and routes of the migrants over the study site, we need more detailed and further studies such as satellite tracking researches.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.89-93
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• 2003

In this study, the food selection of abalone, Haliotis discus hannai, on four various diets, Ulva pertusa, Laminaria japonica, Navicula spp., and artificial diet, was investigated. The abalones in Ulva pertusa and Navicula spp groups had the higher migration rate than the others. The artificial group had the lowest migration rate. As to the growth, Ulva pertusa group had the highest daily increment and the growth rate, which is 120.7 ${\mu}$m and 2.41%. The value of Navicula spp. group is 102.0 ${\mu}$m and 2.04% and that of Laminaria japonica group is 88.7 ${\mu}$m and 1.77%. The lowest one is 81.7 ${\mu}$m and 1.63%, which appeared at the artificial diet group. We suggest that, when breeding Haliotis discus hannai and the diets which is easy to be ingested and digested, as well as contains much nutrient content, should be used. If the artificial diet is used, it should contain low concentration of flesh-eating content.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.294-303
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• 2013

BACKGROUND: It is well known that rice-fields can provide excellent foraging places for birds including seasonal migrants, wintering, and breeding and hence the high biodiversity of rice-fields may be expected. However, how environmental change including climate-changes on life-history and population dynamics in birds on rice-fields has not been fully understood. In order to investigate how climate-change affects population migratory patterns and migration timing, I modeled a population dynamics of birds in rice-fields over a whole year. METHODS AND RESULTS: I applied the Lotka-Volterra equation to model the population dynamics of birds that have been foraging/visiting rice-fields in Korea. The simple model involves the number of interspecific individuals and temperature, and the model parameters are periodic in time as the biological activities related to the migration, wintering and reproduction are seasonal. As results, firstly there was a positive relationship between the variation of seasonal population sizes and temperature change. Secondly, the reduced lengths of season were negatively related to the population size. Overall, the effects of the difference of lengths of season on seasonal population dynamics were higher than the effects of seasonal temperature change. CONCLUSION(S): Climate change can alter population dynamics of birds in rice-fields and hence the variation may affect the fitness, such as reproduction, survival and migration. The unstable balances of population dynamics in birds using paddy rice field as affected by climate change can reduce the population growth and species diversity in rice fields. The results suggest that the agricultural production is partly affected by the unstable balance of population in birds using rice-fields.

• Korean Journal of Environment and Ecology
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• v.25 no.6
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• pp.828-835
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• 2011

This study was conducted to understand the characteristics of bird community, migration, nesting guild, ordination analysis of observed frequency of birds at Jeju Experimental Forests (JEFs) from November 2006 to September 2007 with surveys of two areas by line transect methods and point-count methods at five areas for three consecutive days in each month. Among observed 58 species could be classified into the 24 residents, 9 summer visitors, 9 winter visitors and 16 passage migrants according to migration habit. In species composition, passage migrants are dominant birds at study areas whereas summer and winter visitors are most dominant birds at mainland's forests. We could divide two groups of bird community in the view of monthly species composition, one is November to February group, the other March to July group by ordination analysis. Number of species did not show seasonal fluctuation which is common pattern of bird community in mainland. This pattern reflects that species composition can change during breeding and non-breeding periods, but overall number of species did not change. This can be related with the high use of passage migrants at study area, also suggests that the JEFs can be highly utilized as stopover sites during migration. At mainland's forests, we can observe about five species of woodpeckers, however we just observed the only one species of White-backed Woodpeckers (Dendrocopos leucotos) at study areas. In the view of nesting guild, breeding birds can be grouped into the 9 bush-& ground nesters, 8 canopy nesters, 7 hole nesters and one house nesters. Among hole nesters, we can observe only one species of primary cavity nesters White-backed woodpecker, and the five secondary cavity nesters, that is three species of tits, tricolor flycatchers (Ficedula zanthopygia) and ruddy kingfishers (Halcyon coromanda). Therefore, White-backed woodpeckers can be regarded as a keystone species and forest practice should consider the careful conservation of this species.

• 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.

• Animal Bioscience
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• v.34 no.10
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• pp.1590-1599
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• 2021

Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H₂O₂), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H₂O₂, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H₂O₂, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

• Ocean and Polar Research
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• v.24 no.1
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• pp.115-121
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• 2002

Yubu Island is located within the estuary of the Geum River, South Chungcheong Province $(35^{\circ}59'N,\;126^{\circ}36'E)$, Korea. The island is surrounded by a broad and sandy mudflat, which is typical in the west coast of Korea, and is located 4km off from Gunsan City. Less than 100 humans live on the island, occupying 30 houses. After we discovered that this island was a very important waterbird habitat especially for the East Asian subspecies of the Eurasian oystercatcher, Haematopus ostralegus osculans. Waterbirds were monitored once every month from August 1999 to July 2000. The highest number of oystercatchers counted was 3,200 in December 1999, and the birds seemed to remain in the area continuously from September to next February. About 200 breeding and non-breeding birds remained during the breeding season. In August, early migrants returned to the island, with the number reaching 1,060 individuals. This island is also very important for other waterbirds. Endangered or significant species occurring at this site, and their maximum counts were: chinese egret Egretta eulophotes (5), black-faced spoonbill Platalea minor (17), brant Branta bernicla (1), common shelduck Tadorna tadorna (8,000), hooded crane Grus monacha (2), spoon-billed sandpiper Ewynorhynchus pygmeus (7), dunlin Calidris alpina (6,500), great knot Calidris tenuirostris (24,000), far eastern curlew Numenius madagascariensis (2,500), spotted greenshank Tringa guttifer (4) and Saunders's gull Larus saundersi (1,200). During the 12 month survey period, we observed 52 waterbird species and the total of the maximum counts for the separate species was 73,308, implying that perhaps 150,000 birds could be using the immediate area, if a turnover rate of 2 was assumed.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.263-268
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• 2008

Estimates of genetic gain (in volume growth) and diversity (expressed as status number, $N_s$) were determined in a clonal seed orchard of Pinus koraiensis. The genetic thinning was based on clonal breeding values (represented by general combining ability) obtained from progeny tests, clonal fertility estimated by strobilus production, and clonal size variation determined by the ramet numbers per clone. Parental GCA values for volume growth were calculated, based on height and diameter at breast height measured from field trials. Clonal fertility was estimated from the assessments of strobilus production over twelve years from 1991 to 2003, and used for the calculation of status number. There are 179 clones and 5,268 ramets in 12ha area of P. koraiensis clonal seed orchard. Genetic gain and diversity estimates were determined under assumptions of 30% pollen contamination and inferior genetic value of contaminating pollen. Genetic gain increased as thinning rates were set from 10% to 60%. However, for the higher thinning intensities, the increase of genetic gain was not remarkable. Genetic thinning by means of truncation selection resulted in a greater genetic gain but a large decrease in status number. Status number was represented around 40 clones for 10% through 60% thinning intensities, but for the higher thinning intensities, it was a bit fluctuated. Based on the present results, it could be concluded that thinning rate should not be stronger than 60% to optimize genetic gain while conserving genetic diversity. Consequently 50% or 60% thinning rate might be appropriate for genetic thinning in the clonal seed orchard of P. koraiensis. The effect of pollen contamination on the genetic gain and the consequence of genetic thinning for seed production in the clonal seed orchard, and seed orchard management scheme were also discussed.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.283-295
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• 2002

The number of species and individvals of birds observed in Bibong, Chinju-castle, Nosan and Saho parks were 49 and 4,349, 46 and 6,453, 37 and 2,817, and 33 and 6,014, nespectively The dominant species in all survey areas were shown in the order of Passer montanus(21.8%), Aegithalos spp.(20.7%), Pica pica(8.7%), Hypsipetes amaurotis(7.6%), Parus major(6.4%), Carduelis spp.(4.6%). Migration of birds was the order of residents, summer visitor, winter visitor, and passage migrant. The number of bird species appeared was the fewest in winter as 40 species and the most in spring as 53 species. Species diversity was the highest in Bibong park as 1.3256 and followed in the order of Sanho park, Nosan park, and Chinju-castle park. The nesting guild was higher at outside and artificial nesting guild(7-15 species) compared with hole, canopy, bush nesting guild(1-7 species) in all survey areas. The breeding forage guild was higher at canopy and bush(12-25 species) than that at outside, artificial, and air forage guild(2-8 species).

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.20-30
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• 2009

To study reproductive dynamics of a Gold-spotted pond frog (Rana chosenica) population located at Gangnae, Cheongwon, Chungbuk, Korea, we monitored the population over 207 days between April 17$^{th}$ 2007 and December 18$^{th}$ 2008 using a drift fence accompanied with 20 pitfall traps. The population was located in an agricultural wetland, compromising three small ponds. Gold-spotted pond frogs immigrated into the wetland between April 16$^{th}$ and June 17$^{th}$ and emigrated from the wetland between September 21$^{st}$ and November 12$^{th}$. Precipitation showed a positive correlation with the number of migrated frogs in Autumn 2007 and Spring 2008, but other environmental factors such as air and water temperatures and relative humidity did not show any significant relationships. In general, small frogs first migrated into and from the wetland, but the trend was not strong. Female gold-spotted pond frogs were bigger than males. During the autumn migration, small frogs of which snout-vent length was smaller than 20 mm were found, indicating that successful breeding occurred in the population. Our results could be useful to conserve this endangered species in Korea.