• Animal cells and systems
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• v.8 no.4
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• pp.295-300
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• 2004

In the breeding colony of black-tailed gull, as nests of conspecific neighbors are very closely located, chicks are permanently exposed by sound and visual stimuli produced by adult conspecifics approaching their nests. The chicks, therefore, may need to learn ways to appropriately respond to their parents approach. In this study we experimentally manipulated sensory stimulation that is potentially provided by the parents to the offspring. Chicks incubated in the laboratory were exposed to a mew call of the conspecific adult. Then they were tested in three situations differing in sensory stimulation: 1) visual stimulation only, 2) auditory stimulation only, and 3) Simultaneous visual and auditory stimulations. We observed occurrence of different response of the chicks, which were categorized into three behaviors (begging call response, chirirah call and pecking behavior). We also investigated intensity of the chicks call in response to the different stimulations and the degree of response with age. The chicks exposed to only auditory stimulation made significantly more chirirah calls. The intensities (dB) of the mew call and chicks chirirah call were directly correlated. On the other hand, when chicks just saw the stuffed adult gull, they responded significantly more with a begging call and pecking behavior. In the situation of costimulation, the chicks responded with a begging call and pecking, but less frequently than visual stimulation only. The results suggest that young black-tailed gulls use call repertories to properly respond to parents behavior. Such results suggest an evolutionary process for uncreasing their survival rate in a group breeding site.

• Ocean and Polar Research
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• v.42 no.1
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• pp.89-95
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• 2020

Our study was conducted to examine the nest attendance of the Black-faced Spoonbill (Platalea minor) from 2015 to 2018 at two Islets located in Incheon, South Korea. We visited study sites in March-April and set up the remote sensor cameras at two breeding sites (Mae-do, Guji-do) to observe chick-rearing behavior. Mean nest bout length at Mae-do (female: 4.2 ± 0.1 hr, male: 4.0 ± 0.1 hr) was shorter than at Guji-do (female: 5.3 ± 0.2, male: 6.0 ± 0.3 hr), and trip duration at Mae-do (female: 4.4 ± 0.1 hr, male: 4.0 ± 0.1) was also shorter than at Guji-do (female: 7.0 ± 0.2 hr, male: 7.0 ± 0.3). Mean nest bout length and trip duration at both study sites decreased as chick rearing progressed. Males attended their nests during the daytime, and females attended their nests during the nighttime. Our results showed that females and males' duties were divided by the diel cycle, but the pattern of nest attendance could change depending on the environment of their breeding sites during the chick-rearing period.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.528-534
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• 2009

Styan's Grasshopper Warblers (Locustella pleskei) are vulnerable species distributed in East-Asia only. Its known breeding sites in Korea are remote islets including Hongdo Islet, Chilbal Islet, Mara Islet, and Chuja Islets, and, therefore, the breeding biology of this species is still poorly known. This study was conducted on Mara Islet (N $33^{\circ}$ 06', E $126^{\circ}$ 16') from May to September 2008 to investigate the breeding status and breeding site characteristics of the grasshopper warblers. A total of 11 breeding pairs and their nests were found on trees and shrubs at artificially planted forests and hedges of Pinus thunbergii. The grasshopper warblers preferentially utilized the shrub trees for nesting places, and major nesting trees were Camellia japonica, Pittosporum tobira and Pinus thunbergii as nesting trees. Average heights of nesting trees and nests were $2.77{\pm}1.10m$ and $1.75{\pm}0.56m$, respectively. The grasshopper warblers selected lower shrubs and trees for nesting than randomly selected ones around them, probably to avoid strong and prevailed winds in flat and un vegetated environments on Mara Islet. The shape of nests was a round bowl-type, and measurements of nests were $11.9{\pm}0.5cm$ in exterior nest diameter, $11.1{\pm}1.1cm$ in height of exterior nest, $5.8{\pm}0.4cm$ in interior nest depth, and 6.0cm in interior nest diameter. It incubated eggs until the early August on Mara islet, and incubation periods of Mara Islet was possibly later than that of other areas. Furthermore, the clutch size in the study area was three, and they laid smaller number of eggs than normal clutch size (4~5 eggs) reported in other areas. Although we could not observe any nest predator on this species in the study area, selective cutting and pruning of trees will diminish dense shrub layer of forests. Therefore, it may affect the breeding of this threatened species which prefers dense shrubs of artificially planted forest of Pinus thunbergii. This study suggests that detailed and consistent further research on breeding biology and habitats of the grasshopper warblers are needed to conserve and manage of Pinus thunbergii forests on Mara Islet as an important breeding site of Styan's Grasshopper Warblers.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.703-709
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• 2015

A breeding pair of the Black-faced Spoonbill Platalea minor was firstly recorded on Chilsando Islands, Younggwang, Jeollanamdo Province in 1991. Since the mid 2000s, breeding population on the breeding sites has gradually increased. This study was conducted to identify breeding status and nest site characteristics of the species from May to August, 2013 on Chilsando Islands. We recorded number of nests, length and width of the nest base, slope around the nests, nest materials, distances from the nearest nest, presence of nest cover and nesting area. In 2013 breeding season, 25 of 49 nests produced at least one successful fledging. A total of 55 youngs were successfully fledged and number of fledging per nest was 2.20 individuals. Nesting area was $77.8m^2$ and $93.4m^2$ for Sansando and Yuksando Islet, respectively. Soil and soil mixed with tree root were preferred for substrate of nest base over rock and Brassica napus was dominantly selected as nest materials by Black-faced Spoonbills. Nest characteristics of 22 nests in Sasando and Yuksando Islet varied $49.59{\pm}6.53cm$(mean${\pm}$SD) for length of nest base, $41.00{\pm}5.82cm$ for width of nest base, $20.85{\pm}9.96^{\circ}$ for slope above the nest, $34.09{\pm}17.75^{\circ}$ for slope below the nest and $130.82{\pm}84.17cm$ for distances from the nearest nest. Fifteen pairs (68.2%) occupied where nest cover existed. Nest cover were located in front of the nest for 5 pairs, back of the nest for 9 pairs and both front and back of the nest for 1 pair.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.655-661
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• 2015

A marine algal species was collected from the southern coast of Korea. This alga is characterized by a large and cartilaginous thallus, a dichotomous branching pattern, compressed axes, rare proliferations near the apex, and cystocarps protruded toward surface. In a phylogenetic tree based on rbcL sequences, this species nests in the same clade as Neodilsea yendoana as a terminal clade of the genus Neodilsea. The genetic distance between both sequences within the clade was calculated as 0.2% considered to be in the intraspecific range within the genus. Based on the morphological and molecular data obtained in the present study, this Korean species is identified as N. yendoana. This is the first record of the genus Neodilsea and N. yendoana in Korea.

• English Language & Literature Teaching
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• v.17 no.2
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• pp.59-77
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• 2011

In recent years, as many native English speakers are working in Asia to as English teachers, team teaching with local teachers has been commonly implemented within the Korean EFL classroom. Using qualitative case studies, this paper aims to explore native English-speaking teachers' (NESTs) perceptions of team teaching and their challenges at different secondary Korean schools. The study documents the challenges faced by three foreign teachers embedded in intercultural teaching teams. The data shows that common challenges include vague role distribution among teachers, problems presented by mixed levels of students, large classes, and students' low valuation during foreign teacher's classes, which go ungraded. The study calls for serious governmental efforts to change these fundamental problems and closely examine local factors that strongly affect team teaching practices before initiating a system of importing foreign teachers without proper preparation.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.335-340
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• 2017

A marine brown alga was collected from Geoje, located on the southern coast of Korea. This species shares the generic features of Dictyota and is morphologically characterized by the combined features of erect or prostrate thallus with smooth margin, dichotomous to subdichotomous branches not twisted at the terminal part, absence of surface proliferations, 1-3 cell layered cortex and unilayered medulla, and lack of involucrum in sporangia subtended by a single stalk cell. In a phylogenetic tree based on rbcL sequences, this species nests in the same clade with Dictyota bartayresiana. The genetic distance between both sequences within the clade was calculated as 1.2%, considered to be within the intra-species range for the genus. Based on these morphological and molecular analyses, this Korean alga is identified as D. bartayresiana described originally from the West Indies. This is the first record of D. bartayresiana in Korea.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.952-957
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• 2017

In the course of survey of marine algal flora in Korea, a red algal species was collected from Pohang located in the eastern coast of Korea. This shares features of Hypnea, and is characterized by more or less percurrent axis and numerous and short branchlets densely covering axis and branches with basal constrictions, and absence of lenticular thickenings in medullary cell walls. In a phylogenetic tree based on rbcL sequences, this species nests in the same clade as Hypnea esperi. Genetic distance between this Korean entity and H. esperi was in intraspecific range as 0.6%. This alga is identified as Hypnea esperi based on the morphological and molecular data. This is the first record of H. esperi in Korea.

• 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.

• Korean Journal of Head & Neck Oncology
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• v.20 no.1
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• pp.37-40
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• 2004

Mucinous adenocarcinoma is rarely reported in head and neck region. In other organ, it usually occur in breast, gastrointenstinal tract and so on. The specific histologic findings of mucinous adenocarcinoma are the large amount of extracellular mucin and tumor cell nests such as floating in mucin pool. It may develop rarely in major or minor salivary gland, but only one case of mucinous adenocarcinoma originating from parotid gland was presented in south korea. We report a case of mucinous adenocarcinoma in the tongue base considered to develop from minor salivary gland with a review of literatures.