• Ocean Science Journal
• /
• 제43권4호
• /
• pp.175-182
• /
• 2008

Bottlenose dolphins are the only cetaceans regularly observed in the northern Adriatic Sea, but they survive at low densities and are exposed to significant threats. This study investigates some of the factors that influence habitat use by the animals in a largely homogeneous environment by combining dolphin data with hydrological and physiographical variables sampled from oceanographic ships. Surveys were conducted year-round between 2003 and 2006, totalling 3,397 km of effort. Habitat modelling based on a binary stepwise logistic regression analysis predicted between 81% and 93% of the cells where animals were present. Seven environmental covariates were important predictors: oxygen saturation, water temperature, density anomaly, gradient of density anomaly, turbidity, distance from the nearest coast and bottom depth. The model selected consistent predictors in spring and summer. However, the relationship (inverse or direct) between each predictor and dolphin presence varied among seasons, and different predictors were selected in fall. This suggests that dolphin distribution changed depending on seasonal forcing. As the study area is relatively uniform in terms of bottom topography, habitat use by the animals seems to depend on complex interactions among hydrological variables, caused primarily by seasonal change and likely to determine shifts in prey distribution.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• 제2권4호
• /
• pp.293-297
• /
• 2021

The oriental stork (Ciconia boyciana) is listed as an endangered species internationally. Its resident population has been extirpated in South Korea since 1971. Its predicted historical habitat included forests (54%), rice paddy fields (28%), grasslands (17%), river-streams (less than 1%), and villages (less than 1%) based on pre-extirpation records in a previous study. However, habitat attributes of recently reintroduced oriental storks since 2015 remain unknown. To examine habitat use patterns and home ranges of recently reintroduced oriental storks, 2015-2017 tracking data of 17 individuals were used to analyze their spatial attributes with a Kernel Density Estimate method and breeding status. Their habitat use patterns from peripheral to core areas were highly associated with increasing rice paddy fields (26%) and decreasing forested areas (55%). Scale-dependent home ranges were 51% smaller for breeders than for non-breeders on average. Our study results highlight that the habitat use pattern of reintroduced oriental storks seems to be comparable to the historical pattern where the used area is likely to be more centralized for breeders than for non-breeders in South Korea. Furthermore, the direction of habitat management for oriental storks should focus on biodiversity improvement of rice paddy fields with chemical free cultivation and irrigation.

• Ecology and Resilient Infrastructure
• /
• 제4권4호
• /
• pp.200-206
• /
• 2017

도시화로 인한 서식지의 훼손과 단편화는 전세계적으로 양서류에게 큰 위협이 되고 있다. 본 연구에서는 도시화가 청개구리의 분포와 수도에 미치는 영향을 파악하고자, 인천와 그 주변에 위치한 18개 논에서 청음으로 청개구리의 수도를 측정하고 서식지 환경과 토지 이용을 조사하였다. 인천과 주변 논에서 청개구리의 수도는 0 - 17마리 / 서식지 또는 0 - 41마리 / ha이었다. 청개구리의 수도는 서식지와 도로와의 거리가 멀어짐에 따라서 서식지의 둘레길이 면적이 켜질수록 증가하였다. 일반적인 예측과는 달리 청개구리의 밀도는 서식지의 크기와 음의 상관을, 주변의 토지이용 강도와는 양의 상관관계를 보였다. 따라서 도시화에 의하여 서식지 면적이 감소하고 주변이 개발됨에 따라서 청개구리리가 좁은 서식지로 집중화될 수 있다고 생각된다.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• 제3권4호
• /
• pp.199-203
• /
• 2022

The spring home range and habitat use of the spot-billed duck in Korea were studied using GPS-mobile phone-based telemetry (WT-300). The study areas were Anseong-si, Seosan-si, Nonsan-si, and Sejong-si. Analysis was performed using minimum convex polygon (MCP) and kernel density estimation (KDE) spot-billed ducks had an average home range of 70.28 km² (standard deviation [SD]=84.50, n=6), and a core habitat (50%) 2.66 km² (SD=2.60, n=6), according to MCP and KDE, respectively. Wetlands (41.5%) and rice fields (35.7%) were highly used as habitats. The rice field use rate was high during the day, and the wetland utilization rate was high at night. Rice fields and wetlands were the primary habitats in spring.

• The Korean Journal of Ecology
• /
• 제24권2호
• /
• pp.77-80
• /
• 2001

We investigated the habitat use of cranes, and suggested the proper way to protect and manage the cranes in Cheolwon Basin, which is the most important wintering ground of cranes in Korea. Field surveys were conducted in the wintering seasons from Nov. 1994 to Feb. 1995, and from Nov. 1997 to Feb. 1998. The habitat loss and environmental changes by the road construction and agricultural field rearrangement might have affected the distribution of the cranes. The distribution of cranes seemed to be related with the density of rice grains remained in rice paddies.

• Journal of Ecology and Environment
• /
• 제38권2호
• /
• pp.163-173
• /
• 2015

The occurrence of wild boars (Sus scrofa Linnaeus) and reports of wildlife-vehicle conflicts (i.e., road-kill) involving them have increased in natural forest regions of Korea. In the past few decades, many wildlife passages have been constructed to reduce vehicle collisions involving wildlife species. However, few studies have assessed the habitat suitability of target wildlife species when locating the construction sites of wildlife passages. Target species rarely use wildlife passages if built in an inappropriate location. Therefore, a quantitative habitat model is required to find suitable sites for wildlife passages that can connect the fragmented forest patches of wildlife habitats in Korea. In this study, the wild boar was selected as the target species, and six environmental variables (percentage of Quercus forest, slope aspect, distance to roads, water accessibility, forest stand age and density) were measured. The habitat model for wild boars was developed with a Delphi survey, and habitat suitability maps were delineated for the provinces of Gangwon-do and Jeollanam-do. In this study, 298 and 64 boars were observed in Gangwon-do and Jeollanam-do, respectively. Observations of wild boars derived from the second nationwide natural environmental survey were used to evaluate the habitat model. Habitat suitability maps that superimposed existing road networks suggested that wild boar habitats were severely fragmented in both provinces, particularly in Gangwon-do. To connect the fragmented habitats and prevent wildlife-vehicle collisions, this study proposes 11 and 5 wildlife passage sites in Gangwon-do and Jeollanam-do, respectively.

• Journal of Ecology and Environment
• /
• 제33권1호
• /
• pp.3-13
• /
• 2010

The Tsushima leopard cat, Prionailurus bengalensis euptilurus, a small felid, inhabits only the Tsushima Islands in Japan. Previous studies of the Tsushima leopard cat revealed that natural factors; including sex, reproductive activity, season, and prey distribution and abundance affect leopard cat home range variation and habitat use. In this study, we focused on clarifying how anthropogenic factors influenced home range variation and habitat use of a male Tsushima leopard cat living near a suburban area in January, March, May and September 2005 using radio-tracking. The home range size (100% MCP) of this cat was $0.78\;{\pm}\;0.26\;km^2$ (mean ${\pm}$ SD, n = 4 tracking sessions) across the whole study period. However, the cat did not use all parts of its home range uniformly; rather it used some habitat types selectively. The cat avoided agriculture areas and residential areas in all of the tracking-sessions. On the other hand, the cat showed a weak preference for artificial structures and a strong preference for baiting sites in January and March, while it avoided them in May, and no baiting site was included in its home range in September. These results suggest that anthropogenic factors influenced the ranging patterns and habitat use of the leopard cat living near a suburban area. Artificial structures might provided good resting spaces for the cat in bad weather. When the density of its main prey was low in the winter, the cat tended to rely on artificial prey and had a small home range size.

• 한국환경과학회지
• /
• 제15권11호
• /
• pp.1077-1086
• /
• 2006

This study aims at analyzing relationships between land use and habitat types of winter wildbirds to provide basic understanding of ecosystem for preservation and restoration of urban ecosystem in the future. The research area is Hanam City. Researches on land use types showed Hanam City had 79.1% of greenspace and openspace, but intensive urban development has been taking place in greenspace that is adjacent to urban districts. This has brought the problems of lack of greenspace in urban districts and damages to cultivated areas and grassland. A total of 61 and 8,642 populations of winter wildbird species were observed in research areas. Paradoxornis webbiann(16.91), Passer montanus(11.93), Pica pica(6.88) were dominant species. When they were divided according to habitat types, 20 species of interior species, 8 species of interior-edge generalist species, 12 species of edge species and 3 species of urban species were observed. When which land use type was mostly served as wildbirds habitats was examined, urban species(3 species and 290 populations) was a dominant species in urban districts while in greenspace and openspaece, water species(19species and 3,075 populations) including winter migratory birds was. Among greenspace and openspaece, edge species was dominant in forest while urban species was a dominant species in cultivated areas. This shows there is a need to improve diversity of wildbirds through restoration of cultivated areas in the central part of Hanam City.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• 제2권4호
• /
• pp.285-292
• /
• 2021

We investigated habitat use and home range of a rescued and released white-naped crane using GPS tracking technology in Cheorwon, South Korea, from October 2016 to March 2017. Four types of roosting sites were identified: frozen reservoirs, paddy fields, rivers, and wetlands. Upon arrival, the white-naped crane preferred wetlands in the Demilitarized Zone (DMZ). In late wintering season, it showed a tendency to change main roosting sites in the following order: rice paddies, rivers, and frozen reservoirs. Among 14 sleeping places, Civilian Control Zone (CCZ) with various type of available habitats was more preferred than the DMZ. Places outside of CCZ were rarely used due to anthropogenic disturbances during the night. The tracked white-naped crane widely chose daytime feeding sites while moving around all over rice paddies in the CCZ. Mean diurnal movement distance was 10.5 km with a maximum of 24.8 km. Its home range measured with Minimum Convex Polygon (MCP) and Kernel Density Estimation (KDE) was 172.30 km² with MCP, 159.60 km² with KDE 95%, 132.48 km² with KDE 90%, and 42.45 km² with KDE 50%. All estimated values of home ranges were higher in the early and later winter than those in the middle period.

• Journal of Ecology and Environment
• /
• 제45권4호
• /
• pp.163-169
• /
• 2021

Background: Understanding the habitat characteristics of the endangered Siberian flying squirrel Pteromys volans is the first step in conserving and managing the forests it requires for nesting, gliding, and feeding. Therefore, in the present study, we characterized the habitats of P. volans using GIS analysis of 411 forest sites in South Korea where fecal droppings were found. Results: Fecal signs of P. volans were found in various regions in South Korea, including the Baekdudaegan Mountains. GIS analysis with six environmental layers (vegetation type, wood-age class, diameter at breast height [DBH], crown density, elevation, and distance from stream) revealed that fecal signs of P. volans were more frequently found in broad-leaved deciduous forests (42%) located 200-399 m above sea level (43.1%) and 0-199 m from the nearest stream (53%), with 5th class wood-age (35.3%), middle size class DBH (51.1%), and high crown density (71%). Conclusions: The present study provides information on the biotic and abiotic characteristics of P. volans habitats. In South Korea, the fecal droppings of P. volans were found predominantly old deciduous broadleaf forests. Further studies are needed to reveal whether the more frequent occurrence of P. volans dropping in broadleaf forests may be due to a particular preference of this species for the forests or to a simple reflection of the area of the broadleaf forests occupying a much larger area than other forest types in Korea.