• Journal of fish pathology
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• v.1 no.1
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• pp.31-37
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• 1988

An experiment was carried out in order to reveal the infection species of trematode and the infection demage in the marine bivalves. Metacercaria of Echinostomatidae were found in Mactra veneriformis, Cyclina sinensis and Solen strictus in the vicinity sea of Naecho-do, the estuary of the Keum River in the western coast of Korea. The metacercaria detected from Solen strictus were fed by Larus crassiostris, at 16 days after infection, the adult worm could be seceded. The metacercaria of Himasthla kusasigi were detected from Mactra veneriformis and Cyclina sinensis, their infection rates were 70.4% and 85.7% respectively. The partial infection rates with respect to the body parts were 40.4% and 77.3% in the foot, 17.0% and 12.4% in the gill, 12.6% and 10.3% in the mantle in order. The metacercaria of Acanthoparyphium were found from Solen strictus. The total infection rate was 63% and the partial infection rate was 63% and the partial infection rate was shown foot, mantle and gill in order. The adult worm ceded from Larus crassiostris was indentified as Acanthoparyphium tyosenensis Yamaguti, 1938 from view point of its physical characteristics. Therefore, Mactra veneriformis, Cyclina sinensis would be added as new intermediate hosts, and Echoinostoma decteded from Mactra sulcataria which was studied by author(1969) was revealed as larvae of Acanthoparyphium tyosenensis.

• Journal of Wetlands Research
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• v.7 no.4
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• pp.81-88
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• 2005

A total of 14,034 individual birds, 11 orders 21 families, were observed during the four year study periods from 2001 to 2004 winter season on the lower Taehwa river. In 2001 the species was the highest with 48, and then the lowest with 31 in 2004. Population was peaked with 11,991 in 2002, but the lowest number was 3,476 in 2004. The birds recorded more than 5% relative dominance were Aythya ferina (6,946), Corvus frugilegus (1,643), Larus ridibundus (1,193) and Larus crassirostris (805), and their total numbers were 10,587 individuals, 75.4% of the total individuals. For wintering birds protection on Taehwa river, it is necessary to make feeding site, shelter and buffer zone along the river. Establishment of wall or forest for absorbing sound and light should be created between road and flood plain. Besides these artificial facilities, the public awareness of citizens will be the most important thing to protect birds. Moreover, it is necessary to prepare conservation and management measures for the river bed where Taehwa river meets Dong river where the birds used bamboo forest($2{\times}0.1km^2$) for breeding and roosting.

• Ocean and Polar Research
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• v.28 no.2
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• pp.201-207
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• 2006

We studied variation in clutch size, hatching, fledging and breeding success of the Black-tailed Gull (larus crassirostris) at Hongdo Island, which supported the largest breeding colony of the species, in South Korea in 1997 and 2000 to 2003. Cluck size was recorded in 1,388 nests and breeding success was estimated in 83 nests. Mean clutch size was 1.89 t 0.65. A total of 63.9% of the eggs hatched and 53.5% of the chicks survived until fledged. Breeding success was 34.2%. Causes of breeding failure were eggs missing (14.9%), rotten eggs (15.5%) and predation (2.4%) during the incubation period and chicks missing(35.8%), starvation (7.4%) and pecked chicks (3.2%) during the chick rearing period. In 2002, the main causes of breeding failure were eggs missing (17.2%) and rotten eggs (6.9%) during the incubation period and missing chicks (15.5%), starvation (3.5%) and pecked chicks (6.9%) during the chick rearing period. Most chick mortality occurred within three days after hatching.

• Journal of Veterinary Clinics
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• v.31 no.4
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• pp.354-356
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• 2014

Clinostomum (C.) complanatum is one of the trematode helminthes in birds and causes incidental infection in human. A black-tailed gull (Larus crassirostris) was referred to the Jeju wildlife rescue center. Because of the death of bird after two weeks treatment, necropsy was performed to the bird. Grossly, many living worms adhered to the oral mucosa including pharynx and esophagus were observed. The worms removed were identified as C. complanatum after morphological observation. The linguiform adult worms were $5.19{\pm}0.48mm$ long and $1.80{\pm}0.18mm$ wide. Histopathologically, severe necrosis and surrounding inflammation were observed at the infection sites of adult worm in pharynx and esophagus. This is the first report for C. complanatum infection in wild black-tailed gull in Korea.

• Ocean and Polar Research
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• v.41 no.2
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• pp.99-105
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• 2019

Black-tailed gulls, Larus crassirostris, have been known as resident birds in Korea, but their wintering and breeding habitat ranges were little known about. We investigated the habitat ranges of Blacktailed gulls breeding on Dokdo Island - which is the eastern end of their breeding colonies in Korea. Three adult Black-tailed gulls were fitted with Global Positioning System data loggers in May 2018 and their positions were tracked for 9 days, 245 days and 365 days each respectively. Black-tailed gulls stayed on Dokdo Island until June for breeding purposes and moved down to the southern part of Japan for wintering. The following year, a Black-tailed gull started to move northward in February and returned to Dokdo Island in April. They traveled a total of $207,334-229,507km^2$ (MCP) throughout a whole year. Based on location density categories accounting for 50% of locations, they used 3,618 to $3,803km^2$ in area. Black-tailed gulls breeding on Dokdo Island used smaller habitat ranges during the wintering period than the other periods. This is the first report on the habitat ranges of Black-tailed gulls breeding on Dokdo Island.

• Journal of Wind Energy
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• v.14 no.3
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• pp.69-82
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• 2023

Offshore wind farms (OWFs) should be promoted as part of global efforts to respond to climate change, and efforts to preserve biodiversity in terms of climate change adaptation should also be considered. However, the ecological status of marine birds related to OWFs on the Korean Peninsula, such as habitat and reproduction, are not well known. In this study, ecological reasons for the reproductive status of Black-tailed gulls in Korea and representation related to OWFs, the evaluation direction of marine birds related to OWFs was presented. In a review of the techniques for monitoring marine birds, it was confirmed that Korea also needs to provide basic status information on marine birds at the national level. In addition, this study analyzed the reproductive status and related research status of Black-tailed gulls, an important indicator and dominant species on the Korean Peninsula, in relation to marine development projects including OWFs. Furthermore, the direction of environmental impact assessment preparation and impact prediction for various development projects promoted in the ocean, such as OWFs, was considered.

• Korean Journal of Environment and Ecology
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• v.25 no.2
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• pp.123-131
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• 2011

Seabird distribution in the East Sea was studied from April to May 2007 using line transect counts. We observed a total of 1,379 individuals of 23 species including 14 species of seabird. The overall seabird sighting rate was 2.5 birds $km^{-2}$. The Streaked shearwater(Calonectris leucomelas)(74.5%) was the numerically dominant species. Ancient murrelets(Synthliboramphus antiquus)(8.3%), red-throated divers(Gavia stellata)(5.0%), common terns(Sterna hirundo)(2.1%), Pacific divers(Gavia pacifica)(2.0%), and black-tailed gulls (Larus crassirostris)(1.1%) were also frequently observed. The sightings of seabirds was highest between $36^{\circ}N$ and $37^{\circ}N$ of the coastal area of the Korean peninsular. However, the index of species diversity(H') was higher between $35^{\circ}N$ and $36^{\circ}N$. The sighting rates of most observed species decreased with distance from the coastline. The distribution patterns of Streaked shearwater were linked to the variation in the distribution pattern of minke whales(Balaenoptera acutorostrata). Also, spatial segregation was found in the distributions of the two species of divers(Gavia spp.).

• Journal of Korean Society of Forest Science
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• v.63 no.1
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• pp.1-8
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• 1984

These surveys were conducted to estimate the winter bird population inhabiting in the estuary of Nakdong River by unit distances, by unit times, by sections and by observation points. The results were summarized as follows: 1) A total of 70,032 birds were observed, which composed of 82 species under 27 families. 2) An average of 2,103.06 individuals per kilometer was observed and 23,344.00 individuals per hour. Anatidae showed the most dominance (65.13% of the total), followed by Scolopacidae(14.55%), and Laridae(7.28%). 3) The present population by areas were observed as follows; 61.8% of the total in the tideland and swamp, 31.9% in the surface of water, and 6.4% in the air and land, respectively. 4) Among the five sections, the greatest population was observed in section 3 which figured 22,852 individuals (30.0%), and the least in section 4 (9.8%). 5) In this observation point, six species such as Anas platyrhynchos, Tadorna tadorna, Anser albifrons, Aythya ferina, Calidris alpina and Larus crassirostris were the most dominant birds inhabiting which reached 83.1% of the total.

• Journal of Environmental Science International
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• v.27 no.12
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• pp.1279-1290
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• 2018

Sea gulls are high trophic level consumers in the coastal environment, and thus, which have been widely used to monitor contamination biomagnified through a food web. However, such monitoring studies using sea gulls have been rare in the Korean literature. The National Environmental Specimen Bank chose eggs of a black-tailed gulls (Larus crassirostris) to serve as an environmental specimen for the long-term monitoring of the coastal ecosystem affected by terrestrial pollutants. Black-tailed gull eggs were collected from Baengnyeongdo, Hongdo and Uleungdo, and their DDTs and total mercury content were determined. The highest concentration of ${\Sigma}DDTs$ was $231.6{\pm}106.1{\mu}g/kg$ wet in Baengnyeongdo, followed by $230.0{\pm}123.8{\mu}g/kg$ wet in Ulleungdo, and $117.7{\pm}18.3{\mu}g/kg$ wet in Hongdo. In addition, total mercury was detected at $414.5{\pm}97.6{\mu}g/kg$ wet in Ulleungdo, $363.9{\pm}123.6{\mu}g/kg$ wet in Hongdo, and $237.5{\pm}42.3{\mu}g/kg$ wet in Baengnyeongdo. Relatively high concentrations of the target pollutants were recorded in specimens from Ulleungdo. Additional comprehensive and prolonged studies are required to elucidate spatial and temporal patterns of contamination in black-tailed gull eggs with regard to monitoring contaminant trends in eggs and prey.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.97-104
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• 2012

Newcastle disease virus (NDV) infects a variety of birds with a wide range of clinical signs from asymptomatic to severe. During a 10-month period in 2011, a total of 1,024 sera from wild birds including 42 species of birds in 8 orders were collected and the seroprevalence of NDV in wild birds was evaluated by hemagglutination inhibition (HI) test. Evidence of NDV infection was observed in 12.6% (129/1,024) of wild birds with a maximum prevalence reported in Mandarin duck (27.8%, 32/115) followed by Mallard duck (20.8%, 57/274), Spot-billed duck (11.9%, 36/303), Pintail (2.9%, 1/34), Black-tailed gull (2.9%, 1/34), White-fronted goose (1.8%, 1/56) and Common teal (1.4%, 1/69). None of the other 35 species of wild birds were antibody-positive for NDV. Mandarin duck, Mallard duck and Spot-billed duck showed high sero-prevalance of 12.2% to 42% during winter season (November to March). Our results indicate that Mandarin duck, Mallard duck and Spot-billed duck might be natural reservoirs for NDV in Korea and the prevalence of NDV infection in wild birds displayed a seasonal pattern with high prevalence of NDV in winter season (November to March).