• Journal of Environmental Impact Assessment
• /
• v.24 no.5
• /
• pp.532-548
• /
• 2015

The winter ecology of individual yellow-throated martens(Martes flavigula) intemperate region of Korea were studied through snow-tracking. The study was performed across 3 winter seasons, from January 2011 to February 2013. Total distance of 49.8km was snow tracked (comprising 13 snow-tracking routes) to determine winter foraging habits, general behavior and movement paths of solitary and small groups (1-6 individuals; $mean=2.9{\pm}1.6$) of yellow-throated martens. The martens in the current study were omnivorous, with their winter diet including 9 animal and 5 plant species. Yellow-throated martens searched for food near and under the fallen logs and branches, root plates of fallen trees, around the roots of growing trees, and in small holes in the ground. They also climbed trees to search inside the tree holes and vacant bird nests. Foraging activity was estimated to occur at a frequency of 1.20 times/km, while territory marking occurred 1.42 times/km on average. Of the 60 documented foraging activities we observed, 17 were successful (28.3%). Moving activity and territory marking mainly occurred along ridges, whereas foraging activity was recorded in valleys, slopes, and forest edges. To protect the habitat of this species, the entire forest should be preserved, including the valleys, slopes, and even forest edges as well as main ridges.

• Korean Journal of Ecology and Environment
• /
• v.51 no.2
• /
• pp.168-173
• /
• 2018

Mauremys reevesii is a Korean endemic turtle, and designed as an endangered species and national monument in South Korea. Recently, the population of the species has been dramatically declining because of habitat destruction, pollution and illegal capture. Moreover, small population size, difficulty of securing individuals, and lack of research are factors that impede the effective management of the species. In this study, we tested the effect of individual breeding and feeding on the seven juveniles of M. reevesii. Our results showed individual breeding and feeding were guaranteed the effective growth and development. Noticeable growth was confirmed in both body weight and carapace length. Moreover, the size difference among the individuals appeared at the start of this study decreased at the end of this study. Artificial breeding during the wither season was not caused disorders on the growth, behavior and morphology. This individual breeding may lead to effective growth and development, and it will be a way to increase the survival rate when the juveniles released into the wild.

• Korean Journal of Environment and Ecology
• /
• v.6 no.2
• /
• pp.180-192
• /
• 1993

This study was conducted to investigate bird community and to suggest a proper way how to manage and protect bird community in Sobaeksan National Park. The survey was carried over 3 main trail districts by line transect method to figure out influence factor of inhabitation of wild birds from February to October in 1992. The study results as follows: The observed birds were belong to 9 orders l2 families 58 species, they also have Sparrow Hawk dccipiter nisus, Kestrel Faleo tinnunculus(natural monument no. 323). Scops Owl I'otus scops(natural monument no. :324), Black Woodpecker Dryoaepus martius(natural monument no. 242. R). White-backed Woodpecker Dendroaepos leuotes(R) and Gray-backed Thrush Turdus hortulorum(R). These birds a]so classified into 31 species for residents. 17 species for summer visitor, 6 species for winter visitor. 4 species for passage migrant, respectively. Species richness was 38 species at spry, 33 species at summer. 26 species at autumn and 22 species at winter. The density was 3.00 ea /ha at spring, 2.37 ea /ha at summer, 3.62 ea /ha at autumn and 2.88 ea /ha at winter. Breeding bird community in Sobaeksan National Park was dominated by Hole, Bush-nesting guild and Canopy-foraging guild. Natural vegetation of 900m altitude in 1st section and the grassy plain in 2nd section are to be protected absolutely for the habituation of wild birds. Species richness in 3rd section was higher than any other section owe to a various habitat such as valley. open lands, orchid, farm land and forest etc. Food plants and broad-leaved forest is to be managed for the provision of opulent food resources in autumn and winter, user is to be managed for the successful propagation of wild birds in spring and autumn.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.161-170
• /
• 1982

A trial on the seed production of red sea-bream (Chrysophrys major) was made in Jejudo island at the southern end of Korea, from June, 1980 to August, 1981. Histological observation of the gonads indicated that the main spawning season was June to early July in Jejudo area. The newly-hatched fry were fed Brachionus sp. in the later stages Artemia nauplii, Tigriopus sp. and the minced fish flesh were given. Though during the winter season the water temperature in rearing tanks was decreased as low as $9.2^{\circ}C$, continuous feeding to the juveniles was carried out, showing body weight increase. This implies that winter rearing of juveniles in the near-shore facilities is feasible in the vicinity of Seogwipo area, in Jejudo. Feed coefficient of the juveniles (>23.2 g) was $4.16\sim4.77$ when fed the minced fish flesh.

• Journal of Life Science
• /
• v.16 no.4
• /
• pp.618-625
• /
• 2006

Patterns of induced daily torpor were measured in the striped field mouse, Apodemus agrarius, in response to low temperature, food deprivation and various photoperiods using implanted data loggers. A total of 8 of 21 females entered daily torpor in response to low outside ambient temperature (Ta) during winter and spring, constant low Ta $(4^{\circ}C)$ or food deprivation $(23^{\circ}C)$ during summer, but 2 of 23 males did only in response to low outside Ta during winter. This fact indicates that torpor is an adaptive hypothermia to unpredictable environment in both some males and females, as well as that torpor was inhibited in males in the reproductive season as in other mammals, which is regarded as a strategy not to reduce the chance of copulation. As for females, however, torpor was employed in response to unpredictable environment even in the reproductive season, suggesting that alternative strategies other than keeping the chance of copulation maybe hired by females to keep the population. Torpor bout generally began at $6{\sim}12$ AM, but the decrease of body temperature $(T_b)$ began mainly at $4{\sim}6$ AM at any conditions, the time when Ta is lowest. This strategy might be also adopted for reducing heat loss to unpredictable environment. Minimum $T_b$ of both males and females during torpor did not fall below $16.5^{\circ}C$. Photoperiod had no influence on the incidence and timing of daily torpor in either males and females. The similar timing of torpor bout in response to the 3 different photoperiods (24D, 16L:8D or 8L:16D) under the constant temperatures $(4^{\circ}C\;or\;23{\pm}2^{\circ}C)$ suggests that entering time of torpor might be controlled by the circadian rhythm of the mice rather than by the photoperiod.

• Korean Journal of Ichthyology
• /
• v.34 no.2
• /
• pp.102-112
• /
• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.

• Korean Journal of Ichthyology
• /
• v.35 no.2
• /
• pp.113-120
• /
• 2023

The diet composition of chub mackerel Scomber japonicus were studied using 959 specimens collected in the coastal waters of Jeju Island, Korea from January to November 2022. The size of the specimens ranged from 22.8 to 45.8 cm in total length. S. japonicus were fed mainly on euphausiids that constituted 77.7% in IRI. Fishes were the second largest prey component. Its diet also includes small quantities amphipods, copepods, shrimps, crabs and cephalopods. The diet composition of S. japonicus showed changes in season. The euphausiids feeding rate was highest in summer, whereas the proportion of fishes was higher in winter than in other seasons. The proportion of fishes has increased as the body size of S. japonicus increased, whereas the proportion of euphausiids decreased gradually. As the body size of S. japonicus increased the mean weight of prey per the stomach (mW/ST) tended to increase significantly (One-way ANOVA, P<0.05).

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.467-473
• /
• 2019

The amputation of body parts of wild animals can affect their activities in the wild and the behavior of mothers raising their cubs can cause behavioral characteristics in their offspring. In 2017, an Asiatic black bear was caught in a snare at the Jirisan National Park and had a right forefoot amputation. It was released into the wild the same year and gave birth to two cubs. The seasonal analysis of the behavioral rites of five females who gave birth in the same year as this individual showed specific home ranges, activity altitudes, and movement distances compared to other populations. Physical disabilities in the mother could lead to difficulties in food activity, hibernation, and cub-rearing, but the bear's maternal instincts helped to overcome difficulties in the wild and ensure the cubs' survival. It also became a special experience in the process of promoting the restoration of Asiatic black bears at Jirisan National Park. Although the Asiatic black bear's cubs, which grew up in difficult conditions compared to other populations, are not currently causing problems, continuous monitoring will help determine the success of the disabled mother cub-rearing study. Furthermore, these case studies will be used to establish long-term management directions and plans for conflicts with people from various perspectives.

• Korean Journal of Environment and Ecology
• /
• v.11 no.2
• /
• pp.240-248
• /
• 1997

기존 연구 문헌의 고찰로 서울시 야생조류상의 현황 및 관리방안은 다음과 같이 결론지을 수 있다. 1. 서울시 야생조류상에 대하여 물새와 산새를 모두 연구한 결과가 아직 발표되지 않아 정확한 현황은 파악하기 어려우나 번식기에는 약 40 여종, 겨울철에는 40여종이 서식하는 것으로 볼 수 있으나, 앞으로 정교하며 지속적인 모니터링이 필요하다. 2. 도시림 뿐만 아니라 주변의 패치를 동시에 고려한 통합적 접근방식(intergrated approach)으로 도시림을 연구하여 관리해야 할 것이다. 3. 도시림의 면적은 도시림에 번식하는 야생조류의 종 수에 큰 영향을 미치는 지배적인 인자로써 도시림이 더 이상 다른 토지이용 형태로 전환되지 않도록 관리하는 것이 가장 기초적인 관리 지침이다. 4. 대면적의 숲이 세분화 될 경우, 여름철새의 번식에 지장이 있을 수 있으므로 대면적 숲의 세분화를 막아야 하며, 가능한 한 생태통로(eco-corridor)로 세분화 된 숲을 연결할 수 있는 기술을 개발해야 할 것이다. 5. 도시림에 생육하는 임목 중 대경급 임목은 나무구멍을 둥지자원으로 이용하는 조류의 중요한 은신처와 둥지이므로 대경급 임목을 대신할 수 있는 인공새집의 설치는 나무구멍을 둥지로 이용하는 조류의 번식 종 수를 높이는 방법이다. 또한, 도시림이 시민에 의해 과도하게 이용될 경우, 관목층이 제거되어 관목층을 둥지자원으로 이용하는 조류의 서식에 불리한 조건을 제공할 수 있으므로 등산로 주변에 관목성 수목을 밀식하여 등산로의 확폭과 파괴를 막아야 할 것이다. 풍부한 먹이 자원을 제공하기 위하여 관목층 보호를 꾀하고 임목의 조림과 무육에 힘써야 할 것이다. 6. 동일한 면적에서 번식 조류 종 수를 높이는 방법은 엽층의 피도량을 늘이는 것이다. 현재 서울의 도시림은 엽층의 분화보다는 우선, 피도량의 증가를 위해 노력해야 하며 후에 엽층의 다양성을 높여 산림의 수직적 구조를 다양하게 만들어야 할 것이다. 7. 들고양이와 들개에 의한 소형 조류의 피해가 늘고 있으므로, 야생조류의 천적인 들고양이와 들개를 구제해야 할 것이며, 이에 앞서 서식실태가 조사되어야 할 것이다. 8. 한각을 비롯한 지천의 하변에 서식, 월동하는 물새류와 서식지에 대한 연구와 관리가 시급히 이루어져야 할 것이다. 9. 산불방지와 도시림 정비의 일환으로 실시해 온 관목층과 낙엽 및 죽은 가지를 제거하는 비과학적인 관행과, 하천유지유량을 높이고 하변 정비 및 산불 방지으 ㅣ한 방편으로 진행된 하변 식생 제거는 전문가와 충분히 제고한 후, 없어져야 할 것이다.

• The Korean Journal of Soil Zoology
• /
• v.5 no.2
• /
• pp.125-131
• /
• 2000

Disposing technique for dairy cattle manure using earthworms and the possibility of utilizing earthworms in poultry feed were investigated. In addition, chemical properties of manure and cast of earthworms were investigated. Temperature in the vinyl-house for earthworm nursery was able to be maintained above 0$\^{C}$ in winter and 25-28$\^{C}$ in summer. In closed-covering method, the number of escaped earthworms was the highest among three covering methods. The time was longer after manure excretion, the numbers of escaped earthworm were higher. There were some incidences of mortality of earthworm in closed-covering site. The amount of manure ingested by earthworm was increased in order of non-covering, closed-covering and gap-covering method. Fresh manure was more ingested than old one by earthworm. Earthworms reduced manure about 50% on the dry weight base and reduced total amounts of N, P$_2$O$\_$5/ and K$_2$O of manure by 41, 50 and 60%, respectively. Earthworm could be utilized by adult poultry (>60 g) for feeding. However, adverse effect of live earthworm was observed with young poultry (<450 g).