The common snapping turtle (Chelydra serpentina), which is native to North America, started to be imported into South Korea as pets in the 1990s. The turtle was sold in supermarkets and pet shops nationwide at low prices such as 20 USD. These non-native turtles, with their large size and strong predatory nature, have been consistently discovered in the wild in South Korea beginning in 2014, and they were designated as an ecosystem-disturbing species (EDS) in October 2022. Until June 30, 2023, a collection system was implemented to reduce the abandonment problem of C. serpentina due to their designation as an EDS. In this study, we analyzed the impacts of the legal designation as an ecologically disturbing species and the collection system of C. serpentina on their abandonment and surrender. Our findings showed that designation as EDS did not affect the abandonment of C. serpentina. Meanwhile, the collection system led to cases of immediate surrender. Within 3 years of post-purchase, 41.8% of the turtles were surrendered, and 67.5% were surrendered when they reached 3 kg. Determining the impact of the legal designation as an EDS may be currently limited due to the difficulty of detecting C. serpentina in the wild. On the other hand, cases of surrender through the collection system are considered to be effective as they have been shown to reduce the abandonment of this newly designated ecosystem-disturbing species.

Amphibians are the world's most threatened group of animals, with approximately 41% facing extinction. Contrary to this global trend, the number of amphibian species in Korea has increased by approximately 53.3% over the past 20 years. In particular, salamanders within the genus Hynobius showed even greater diversity, with the number increasing three-fold from two species to seven. However, morphological and ecological traits required for the clear differentiation of these animals are yet to be determined, leading to much confusion. In this study, we investigated the validity of using size traits for species identification, as this method is currently considered a rule of thumb when differentiating Geoje salamanders (Hynobius geojeensis), cryptic Uiryeong salamanders (H. perplicatus), and Korean small salamanders (H. unisacculus). Our study revealed that sex, study period, and habitat were all factors associated with significant differences in snout-vent length, head width, and body weight. Differences in these size traits were evident both between and within species. Our results show that body size traits applied in the recent classification of the three new salamander species could not be seen as a suitable criterion. Such identification methods based solely on body size not only cause great confusion in the field but will also limit future research on Korean Hynobius salamanders.

글로벌화가 진행됨에 따라 외래생물에 대한 문제가 점점 커지고 있으며, 전 세계적인 규모로 확대되고 있다. 국내의 경우, 야생에서 서식하는 외래종 중 외래거북이 발견되는 사례가 빠르게 증가하고 있다. 1970년대 처음으로 수입된 붉은귀거북 (Trachemys scripta elegans)을 포함하여, 15여 종의 외래거북이 최근 국내 야생에서 확인되었다. 게다가, 2019년 10월 15일, 광주광역시에 위치한 풍암천에서 악어거북(Macrochelys temminckii) 한 개체가 발견되었다. 외래생물 관련 문제가 커지는 시기에 큰 크기와 공격적인 성향을 가진 악어거북의 발견 사례는 큰 이슈가 되었으며, 다수의 대중매체를 통해 기사화되 었다. 이에 따라 본 연구에서는 악어거북 발견 기사에 달린 댓글(의견)들을 통해 대중들이 가지고 있는 외래생물에 대한 인식을 알아보고자 하였다. 악어거북 기사에 달린 댓글은 총 1,100개였다. 그 중 342개(31.1%)가 외래생물과 연관성을 보였다. 연관성이 있었던 글(n=342) 중 외래생물이 문제가 될 것이라는 댓글은 전체의 97.7%(n=334)였다. 외래생물이 문제가 되는 이유(n=42)에는 생태계교란(n=31, 73.8%)과 공격성(n=11, 26.2%)이 포함되었다. 외래생물 침입 문제가 발생하는 원인으로는 책임감 부재(n=122, 51.7%)가 가장 많이 언급되었으며, 무분별한 수입 및 거래(n=99, 42.0%), 관련 제도 부재(n=13, 5.5%), 처리 방법의 부재(n=2, 0.8%)가 뒤를 이었다. 대중은 외래생물 문제를 해결하기 위한 방안(n=129)으로 등록제(animal registration)의 필요성(n=59, 45.7%)을 가장 많이 언급하였다. 본 연구를 통해 대중이 외래생물에 대한 심각성을 인식하고 있음을 확인할 수 있었다. 본 연구에서 확인한 외래생물에 대한 대중들의 인식과 의견은 연구자와 정부가 충분히 참고할 필요가 있으며, 추후 외래생물의 관리를 위한 정책 방향을 설정하는데 중요한 근거가 될 것이다.

Five species of the subfamily Cicadinae are found in urban areas at the center of the Korean peninsula, including Cryptotympana atrata, Hyalessa fuscata, Meimuna mongolica, Meimuna opalifera and Graptopsaltria nigrofuscata. Out of those species, the densities of C. atrata and H. fuscata are generally high in the urban area. I hypothesized that there is a vigorous acoustic interaction where two species are abundant. We tested this hypothesis by conducting the 24-h recording experiments in four localities: Gwacheon(GC), Jamsil(JS), Ewha University(EU) and Yangpyeong(YP). Based on the preliminary enumeration surveys of exuviae, GC and JS were designated as high density localities and EU and JS were as low density localities. The results of 24-h recordings and abiotic factor based on the multinomial logistic regression showed that C. atrata and H. fuscata were negatively correlated in high density area GC and JS. In JS and EU, the density of H. fuscata is close to each other. However, the probability of chorusing in JS is significantly lower than EU. This might be due to acoustic competition between two species. Moreover, we confirmed that the choruses of males of C. atrata produced loud choruses usually during the day when temperature high and males of H. fuscata produced calling song throughout the day but peaked in the morning and night. Consequently, multi-species cicada in different temporal pattern probably cannot be explained by only acoustic interaction but the combination of both abiotic and biotic factors probably constrain multi-species cicada to call together during the limited time windows.

Advertisement songs play an important role on species recognition and mate choice in cicadas. Males generate complex species-specific calling songs to attract conspecific females. In central Korea, Cryptotympana atrata, Meimuna mongolica and Hyalessa fuscata are widely distributed, yet their songs have not been described. We analyzed acoustic characteristics of these cicadas’ advertisement songs in temporal and spectral domains. In sum, C. atrata’s songs followed the pulse-echeme pattern, in which each echeme consisted of groups of pulses with the peak frequency of 6423 ± 589 Hz. In M. mongolica, the calling song had the pulse-echeme-combined echeme-phrase structure. A group of three echemes formed one combined echeme, and one full phrase comprised hundreds of combined echemes. Lastly, the calling song of H. fuscata was constructed of the pulseecheme- phrase structure, in which one full phrase included a train of low and high-frequency echemes and the ending echeme at the end of the phrase. The carrier frequency of low frequency echeme was 4576 ± 151 Hz and that of high frequency one was 14089 ± 628 Hz.

Five species of the subfamily Cicadinae are typically found in urban areas of central Korea, including Cryptotympana atrata, Graptopsaltria nigrofuscata, Hyalessa fuscata, Meimuna mongolica, and Meimuna opalifera. These species form multi-species choruses. We hypothesized that there is a negative relationship between dominance of choruses among cicada species. We tested this hypothesis by conducting the 24-h recording experiments in four localities: Gawcheon, Jamsil, Ewha University, and Yangpyeong. Based on the enumeration surveys of exuviae, the results of 24-h recordings showed that choruses of C. atrata and H. fuscata were negatively correlated with other in Jamsil and Ewha University, but were positively correlated with other in Gawcheon and Yangpyeong. Thus, it seemed unclear cicada species competed with each other negatively over. Males of C. atrata produced calling songs usually during the day at temperatures typically higher than 28 C°. However, males of H. fuscata produced calling songs throughout the day at a wide range of temperatures. As a result, the chorus of C. atrata dominated during the day, but that of H. fuscata in urban areas where the densities of C. atrata were sufficiently high.

Collection of ecological data such as the temporo-spatial distribution of a species is very difficult, due to broad distribution over large areas, phenology, and lack of resources for field survey. Citizen science, which is a cooperative scientific endeavor between researchers and interested citizens, is ideal for collecting large-scale ecological data. However, lack of proper equipment, species identification, and/or communication between researchers and participants are hindrance for a successful citizen science project. Here, we introduce the concept and methods of large-scale ecological data collection using smartphone apps. Most of the ecological data typically consist of sound or video recording, picture, geographic coordinate, and notes. There are several apps that can collect some or all of these ecological data. Furthermore, the result of a survey can be reported to researchers using Google Docs. The data collected by non-specialists can be validated by cross-checking of the survey report by Google Docs and the ecological data sent by apps. Finally, we report the results of a citizen science project in which temporo-spatial distributions of cicada species in Korea were studied via smartphone apps and Google Docs.

In Hymenoptera, thanks to its haplodiploid sex determination, arrhenotokous parasitoid females are able to control offspring sex ratio by determining whether to use sperm or not at the time of oviposition. However, the offspring sex ratio may also be influenced by the mating behavior of a male. When a male searches females, he will have more chances to encounter with other males in a high male density population than low male density population. If the male is competitive, the male can find females faster and may have longer copulation time, and eventually transfer more sperm than other males. In this study, we investigated mate searching time, copulation duration and offspring sex ratio as a function of the male density. Although the results show difference between searching time and copulation duration, they are not statistically significant. We will discuss the statistical consequence, male density dependent offspring sex ratio and its evolutionary implications.