• Journal of Ecology and Environment
• /
• v.43 no.3
• /
• pp.282-288
• /
• 2019

We investigated the changes in the population size and inter-specific space usage for breeding in mixed breeding sites of the great cormorant (Phalacrocorax carbo), grey heron (Ardea cinerea), great egret (Ardea alba modesta) and intermediate egret (Egretta intermedia) in Gammul-myeon, Goesan-gun, Chungcheongbuk-do, South Korea, in 2016-2017. These species bred in two adjacent habitats (site A and site B). The number of breeding pairs of all species and the size of the breeding area at site B increased in 2017. In 2017, great cormorants at site B occupied the breeding sites previously occupied by the other species in 2016, while the grey heron and great egret occupied the sites around the great cormorant breeding site. The heights of nest trees and nests of great cormorant and grey heron did not differ temporally, but these heights in site B were significantly higher than those in site A for great cormorants. For great egrets, these greatly decreased in site B in 2017. Thus, the great cormorant either moved to favourable nest sites for breeding success or selected nest sites used by the herons in the previous year. Further studies of these two possibilities are necessary.

• Fisheries and Aquatic Sciences
• /
• v.26 no.4
• /
• pp.282-293
• /
• 2023

Nile perch and Nile tilapia are major commercial species in Uganda, and thus require continuous production. However, their production is impacted by anthropogenic activities such as fishing in breeding habitats. The aim of this study was to identify and characterize Nile perch and Nile tilapia fish breeding habitats on Lake Kyoga. Water quality, lake bottom, fish and vegetation type samples were collected from 20 sites in April of 2021 and 2022. Key informant interviews were conducted with experienced fishermen at five fish landing sites. The water quality parameters indicated significant difference within the sites using analysis of variance. Sandy and muddy bottom types were equally spread at 40% each by use of a pie chart. Fish gonads showed no significant difference among the 20 sites. Bivariate correlation analysis of the vegetation types indicated a strong negative correlation with Nile perch while Nile tilapia had a positive correlation. Principal component analysis of the water quality, fish gonads and habitat vegetation components cumulatively contributed 82.5% in characterizing a fish breeding habitat. Four sites for Nile perch and four sites for Nile tilapia were characterized as breeding sites on Lake Kyoga and are recommended for mapping and gazettement as breeding habitats for sustainable fisheries management.

• Korean Journal of Ecology and Environment
• /
• v.52 no.4
• /
• pp.378-384
• /
• 2019

Red-eared slider, Trachemys scripta elegans, is one of the most famous species to disturb native ecosystems in the world. In South Korea, the species was imported as pet, and now it is found whole of the country. Recent, natural breeding and spreading of the turtle has been reported. In this paper, we investigated the environmental factors to affect the reproduction of T. s. elegans. We surveyed the distribution of the turtle in Jeju island, South Korea, between 2012 to 2017. We compared the land covers and climate of habitats from breeding sites and non-breeding sites. The species was found from 38 sites in Jeju island; 21 of breeding sites and 17 of non-breeding sites. The number of total and only adult turtles was significantly higher in breeding sites than non-breeding sites (P<0.05). In breeding site, the reproduction rate from the farmland was significantly higher than others(P<0.05). However, the rate of land covers was not significant in non-breeding site (P>0.05). The difference on the climate between breeding and non-breeding was not significant(P>0.05). Moreover, none of climate factors affected to reproduction of T. s. elegans(P>0.05). Our study showed that the land covers surrounding the habitats are more important than climate for reproduction of T. s. elegans in Jeju island. This result indicates investigating the habitat and surrounding is necessary for the control of reproduction and spreading of the introduced species.

• The Korean Journal of Ecology
• /
• v.24 no.4
• /
• pp.219-222
• /
• 2001

The study was conducted to get the basic information for proper protection and management of black-faced spoonbill and their habitats in western coast of South Korea. The species was observed in 8 sites of western coast of South Korea in spring 2000. We confirmed breeding of this species at least 4 pairs in Seokdo island. This island is considered likely to be an imortant breeding site together with Yodo island, Hambakdo island and Yokdo island. Also, we observed breeding of herring gull in Seokdo island and small island nearby Boleumdo island for the first time in South Korea. Chilsando island, Cheonsuman bay and Gyeokyeolbiyeoldo island were considered as stopovers located on the Korean Peninsula route. The other sites were considered as summering sites of the black-faced spoonbill. Especially the birds were constantly observed from breeding season to postbreeding season in Seonduri and Yeochari of Ganghwado island. We have counted maximum 88 individuals gathered at Gaksiyeo in Seonduri and Yeochari on September 3, 2000. The species seemed to gather at these sites after breeding for migration to wintering ground in September. We also surveyed changes of the number of individuals as time of the ebb and flow on September 3 and 6, 2000, their time budgets were affected by the ebb and flow in these sites.

• Animal Systematics, Evolution and Diversity
• /
• v.26 no.3
• /
• pp.191-196
• /
• 2010

The Oriental White Stork (Ciconia boyciana) and the Crested Ibis (Nipponia nippon) are wetland species listed as "Endangered" on the IUCN Red List of Threatened Species. The two species were once common on the Korean peninsula, but have experienced a severe population reduction in the past decades. Currently, they are officially extinct in Korea. At present, reintroduction programs to release the birds to the wild are in progress in Korea as well as in Japan. In this study, we surveyed the historic breeding sites of the two species using the literature and face-to-face interviews with local people as a step toward determining appropriate breeding habitats for reintroduction. We found 26 historic breeding sites for the Oriental White Stork in Chungcheong-do and Gyeonggi-do, but did not find any breeding sites for the Crested Ibis. These findings suggest that the Oriental White Stork was resident, while the Crested Ibis was a winter visitor to Korea. Based on these results, we discuss the possibilities for successful reintroduction of the two species in Korea.

• Journal of Environmental Impact Assessment
• /
• v.18 no.3
• /
• pp.123-129
• /
• 2009

In Korea the population of breeding house swallow is continuously decreasing. In this regard this study was conducted to find out the overall population trend during 2001-2005. The areas of urban and rural sites were separated to estimate population. Also the sites in Yangpyung areas were chosen to compare population density between two sites during Mar-Aug, 2006. The house swallow had two breeding periods and I tried to correlated amount of days of incubation and number of eggs in the nest. After egg hatching the homing behavior also was estimated assuming lack of foods takes longer to bring foods back to the nest. This study signified that a long term study should be conducted for population change and spring arrival time due to climate change in Korea.

• Ocean and Polar Research
• /
• v.41 no.3
• /
• pp.147-157
• /
• 2019

Our study was conducted to examine differences in incubation behavior among breeding sites and the relationship between factor affecting environmental change and incubation behavior of the Black-faced Spoonbill (Platalea minor). We set up the remote sensor cameras at three breeding sites (Mae-do, Namdongji, Guji-do) to observe incubation behavior in Gyeonggi Bay, South Korea from 2015 to 2018. We analyzed effects of breeding year, day of incubation started, day of incubation, the time of incubation exchanges and sex on incubation bout length. Mean incubation bout length of females (Mae-do: $7.19{\pm}0.23$ hours, Namdongji: $6.08{\pm}0.23$ hours, Guji-do: $7.96{\pm}0.30$ hours) was longer than males (Mae-do: $6.14{\pm}0.21$ hours, Namdongji: $5.45{\pm}0.28$ hours, Guji-do: $7.38{\pm}0.29$ hours). Mean incubation bout length was longer in Guji-do than other study sites. Incubation bout length tended to increase with the clutch initiation date. Males incubated their eggs at day time while female did at night time, these tendencies were observed more clearly in Guji-do. The proportion of time spent incubating of females was higher than males. Males' proportion increased as incubation progressed and increased rate in Guji-do was higher than other study sites. Our results showed that incubation rhythm of the Black-faced Spoonbill differed among breeding sites and varied with the environmental cycle.

• Ocean and Polar Research
• /
• v.31 no.3
• /
• pp.277-282
• /
• 2009

Saunders' gulls (Laurs saundersi) which are listed as globally vulnerable species on the IUCN Red List are distributed in East Asia and breed mainly in China and Korea. Their population is estimated to be between 7,100 to 9,600. Songdo reclaimed lands in the western coast of South Korea are the main breeding sites for these species. However, most of these breeding sites have been seriously disturbed in the last several years because of new urban development constructions. This study was conducted to provide baseline data on the breeding ecology of Saunders' gulls. Since 1998, the breeding population has rapidly increased in South Korea, with the number of nests rising from 85 nests in 2000 to 185 nests in 2005. Egg volume is more variable than breadth or length. Clutch size, hatching and breeding success were $2.9{\pm}0.81$ (n=182, mean$\pm$sd.), 48.07% (75 hatched egg/156 eggs) and 29.08% (155 fledglings/533 eggs), respectively. Factors affecting breeding failure were predation, rainfall, starvation and supernormal clutches. These results are provided along with other cited literature to argue for conservation of Saunders' gulls.

• Journal of Ecology and Environment
• /
• v.30 no.4
• /
• pp.341-346
• /
• 2007

Nest density was determined and tree and soil characteristics around Nycticorax nycticorax breeding sites and non-breeding sites on Bamsum Island in Seoul were analyzed from May 2005 to October 2006 to identify breeding site preferences of N. nycticorax and the effects of N. nycticorax nesting density on nesting tree structure and soil characteristics. N. nycticorax preferred trees of low height ($3.5{\sim}6$ m) and small diameter at breast height in high density Salix communities. Excrement of heron juveniles was dropped on the soil under the nests. The soil nutrient content under nests (P: 126.0 mg/kg, N: 202.8 mg/kg, EC: 549 ${\mu}S/cm$, pH 4.7) was much higher than that of control soils from Bamsum Island not enriched by heron excrement (P: 41.5 mg/kg, N: 42.0 mg/kg, EC: 342 ${\mu}S/cm$, pH 5.1). Formation of Salix communities on the shores of Bamsum Island is ongoing, and their structure has been directly influenced by annual flooding. After flooding, the nutrient content differences between heron-affected soils and control soils were not significant. This might be the reason that Salix communities on Bamsum were not affected by nesting herons as in other terrestrial communities where herons nest. This result indicates that flooding plays an important role in sustaining Salix communities on Bamsum Island where herons nest. The results of this study may increase understanding of N. nycticorax breeding behavior which may be useful for conservation planning.

• The Korean Journal of Ecology
• /
• v.20 no.4
• /
• pp.251-258
• /
• 1997

Few attempts have been made to discover the ecological function of coarse woody debris (CWD) despite its importance to small mammal population. Twenty-five pitfall traps and a hundred live traps were placed in three sites with high amounts of CWD and three sites with low amounts of CWD. Eleven species were caught, and Peromyscus maniculatus was the most abundant (45.6%, n=605). Among 11 speices, abundance of Tamias townsendii and Clethronomys gapperi were higher in sites with high amounts of CWD than in sites with low amounts of CWD. Home range size was larger in breeding season than in non-breeding season indicating mating search. Resident time of Peromyscus maniculatus was longer in sites with high amounts of CWD implying better stability in population. The increasing amount of coarse woody debris (CWD) enhanced the habitat use by small mammals, and animals in high amounts of CWD were more abundant and stable in population fluctuation. This study, therefore, concludes that CWD is a critical habitat element for small mammals in forest ecosystem.