Marine debris ingestion by adults and fledglings of Swinhoe's storm petrels in the Republic of Korea.

Procellariiformes are highly vulnerable to marine plastic pollution due to their species-specific life histories. In particular, storm petrels are known to be one of the most vulnerable species with respect to plastic ingestion. In this study, we examined the plastic ingestion by adults and fledglings of Swinhoe's storm petrels on Chilbal Island, one of the largest breeding colonies for this species. During 2013 and 2014, we collected adult and fledgling carcasses and analyzed their stomach contents. The results showed that both adults and juveniles were consuming mostly plastics. Most of the collected Swhinhoe's storm petrels were consuming microplastic, with juveniles consuming a higher average amount of plastic than adults. The type of plastic ingested was more threadlike in adults and fragments in juveniles. In conclusion, the characteristics of ingested plastics differed between adults and juveniles, suggesting that analyzing individual age may be important for monitoring plastic ingestion in the future.

Toxoplasma gondii and Rickettsia spp. in ticks collected from migratory birds in the Republic of Korea.

Migratory birds disperse ticks and associated tick-borne pathogens along their migratory routes. Four selected pathogens of medical importance (Coxiella burnetii, Rickettsia spp., Francisella tularensis, and Toxoplasma gondii) were targeted for detection in 804 ticks (365 pools) collected from migratory birds at Hong and Heuksan Islands in the Republic of Korea (ROK) from 2010 to 2011 and 2016. Toxoplasma gondii and Rickettsia spp., were detected in 1/365 (0.27%) and 34/365 (9.32%) pools of ticks, respectively. T. gondii and five rickettsial species were recorded in ticks collected from migratory birds for the first time in ROK. The five rickettsial species (R. monacensis, Candidatus Rickettsia longicornii, R. japonica, R. raoultii, and R. tamurae) were identified using sequence and phylogenetic analysis using ompA and gltA gene fragments. Rickettsia spp. are important pathogens that cause rickettsiosis in humans, with cases recorded in the ROK. These results provide important evidence for the potential role of migratory birds in the introduction and dispersal of T. gondii and Rickettsia spp. along their migratory routes and raise awareness of potential transmission of zoonotic tick-borne pathogens associated with migratory birds in the ROK.

Detection of Rickettsia lusitaniae Among Ornithodoros sawaii Soft Ticks Collected From Japanese Murrelet Seabird Nest Material From Gugul Island, Republic of Korea.

In a follow-up to the investigations of soft ticks identified from seabird nest soil and litter collected from coastal islands of the Republic of Korea (ROK), Ornithodoros sawaii and Ornithodoros capensis were assessed for the presence and identification of rickettsiae. Ticks collected from samples of 50-100 g of nest litter and soil from seabird nests were identified individually by morphological techniques, and species confirmed by sequencing of the mt-rrs gene. Subsequently, tick DNA preparations were screened for the presence of rickettsiae using a genus-specific nested PCR (nPCR) assay targeting the 17 kDa antigen gene. The amplicons from the 17 kDa assay and two additional nPCR assays targeting the gltA and ompB gene fragments were sequenced and used to identify the rickettsiae. A total of 134 soft ticks belonging to two species, O. sawaii Kitaoka & Suzuki 1973 (n = 125) and O. capensis Neumann 1901 (n = 9), were collected. Rickettsia lusitaniae DNA was detected and identified among O. sawaii ticks (n = 11, 8.8%) collected from nest litter and soil of the Japanese murrelet (Synthliboramphus wumizusume Temminck 1836) at Gugul Island along the western coastal area of the ROK. This study confirmed for the first time the presence of R. lusitaniae associated with O. sawaii collected from migratory seabird nests in the ROK.

Molecular Detection and Phylogenetic Analysis of Anaplasma and Borrelia Species in Ticks Collected from Migratory Birds at Heuksan, Hong, and Nan Islands, Republic of Korea.

The extended distribution and potential introduction of exotic ticks and associated tick-borne pathogens along the northern and southern routes of migratory birds pose zoonotic tick-borne disease risks to wild and domestic animals and incidentally to humans. A knowledge of bird migratory patterns, species of attached ticks, and associated pathogens during their migrations to and from their feeding and nesting grounds is central to understanding associated tick-borne disease risks. Tick-borne disease surveillance was conducted from 2010 to 2011 and 2016 at Hong-do (do = island), Heuksan-do, and Nan-do, major stopovers for migratory birds in Republic of Korea (ROK), as part of the Migratory Birds Research Center bird-banding program for studying bird migration patterns in the ROK. A total of 877 ticks belonging to three genera and nine species were collected, Ixodes turdus (576, 65.7%), Haemaphysalis flava (134, 15.3%), H. longicornis (91, 10.4%), I. nipponensis (56, 6.4%), H. formosensis (7, 0.8%), H. ornithophila (6, 0.7%), H. phasiana (5, 0.6%), H. concinna (1, 0.1%), and Amblyomma testudinarium (1, 0.1%) were collected from 274 birds belonging to 20 genera and 41 species. A total of 15/380 pools (3.95%) were positive for Borrelia species (14 pools of I. turdus and 1 pool of H. flava), while only 1/380 pools (0.26%) was positive for Anaplasma phagocytophilum (1 pool of I. nipponensis). Our findings support the role of migratory birds as possible vectors for the introduction of tick-borne pathogens, which requires continuous monitoring for the potential introduction of ticks and their associated tick-borne pathogens.

Comparison of retinal layer thickness measurements obtained using two different swept-source optical coherence tomography imaging modes.

PURPOSE: To compare the retinal layer thickness values obtained using two swept-source optical coherence tomography (OCT) wide modes. METHODS: This study included fifty-four healthy eyes. Three-dimensional (3D) wide and 12 radial wide OCT scans were performed in each eye on the same day. Full retinal, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GC-IPL) thicknesses with fully automated segmentation obtained in 3D wide mode, and with semi-automated correction and fully automated segmentation obtained in 12 radial wide scan. RESULTS: The intraclass correlation coefficients for full retinal thickness measurements obtained by the two protocols with fully automated segmentation were from 0.958 to 0.996, 0.754-0.918 for GC-IPL thickness measurements, and 0.013-0.727 for RNFL thickness measurements, in the nine ETDRS subfields. CONCLUSIONS: The full retinal thickness measurements determined using both fully automated segmentation algorithms were reliable and clinically acceptable. However, segmentation errors are shown when using the 12 radial wide scanning protocol with fully automated segmentation for measurement of RNFL and GC-IPL thickness.

Effectiveness of Morphological Sex Determination in the East Asian Barn Swallow (Hirundo rustica gutturalis) on Spring Migration.

Hyun-Young Nam, Seung-Yeon Lee, Sook-Young Cho, Chang-Yong Choi, Se-Young Park, Gi-Chang Bing, Chang-uk Park, Seul-Gi Seo, and Yang-Mo Kim (2018) Information on sexual dimorphism helps explain a species' evolution in sexual selection and conservation issues such as sex-specific response in environmental changes. The Barn Swallow (Hirundo rustica) is a well-known sexually dimorphic species in which males have longer tail streamers than females. However, when compared with the European-African or American subspecies, little information is available on morphological sex determination in the East Asian subspecies H. r. gutturalis, especially outside the breeding season, when opportunities for molecular sexing are often limited and morphological clues may be the only ones available for sex determination. We collected morphological data on H. r. gutturalis during the northbound spring migration at a stopover site off the Korean coast. Two of eight measured variables - streamer length (the difference in length between the 5th and 6th rectrices; T6-T5) and length of the white patch on the outermost tail (6th rectrix; T6) - were selected as the best predictors for sex determination by stepwise discriminant analysis. Quadratic discriminant functions based on these variables showed that 92.4-93.5% of females and 82.9% of males were correctly classified. Our results provide baseline information that will benefit more accurate sex determination of the East Asian Barn Swallows, especially during the early months of a calendar year in non-breeding and stopover areas.