Jong Koo Lee

The transparency and reflectivity of glass are primary factors contributing to bird collisions, as they prevent birds from recognizing glass surfaces as obstacles. However, the effectiveness of bird collision prevention products is primarily evaluated through transparency-based tunnel tests, which do not adequately account for the reflective conditions commonly found on building glass. We developed an indoor flight tunnel system that simulated sky reflections on glass surfaces and compared avoidance responses to three bird collision prevention patterned samples under both transparent and reflective conditions. A total of 507 wild small passerines were tested, each undergoing a single flight trial. All three patterned samples showed lower avoidance rates under reflective than transparent conditions, but the overall effect of test condition on avoidance was not statistically significant. The frequency of invalid flights increased significantly under reflective conditions. These findings suggest that avoidance responses to bird collision prevention products may vary between transparent and reflective test configurations, although the magnitude of this difference remains uncertain. Incorporating reflective conditions alongside conventional transparency-based tests may therefore provide complementary information for evaluating product performance under different optical conditions.

Accurate estimation of population density and spatial distribution is essential for wildlife conservation and management, yet conventional survey methods face substantial limitations. Estimating the density of medium- to large-sized mammals remains particularly challenging due to difficulties in direct observation and methodological constraints. This study qualitatively evaluated the detection performance and species identification capability of real-time drone surveys and assessed the applicability of distance sampling for density estimation. Surveys were conducted in a reedbed in Yeonsu, Incheon, and a plantation forest in Chungju, South Korea. Real-time drone surveys combined with line-transect sampling were applied in Yeonsu, whereas point-transect sampling was used in Chungju. Across nine line-transect surveys, 270 raccoon dogs ( Nyctereutes procyonoides ) were recorded, yielding an estimated density of 31.8 ind/km ² with a relatively high detection probability (73.7%). In contrast, four point-transect surveys detected 35 water deer ( Hydropotes inermis ), resulting in an estimated density of 30.6 ind/km ² but with low detection probability (34.4%) and wide confidence intervals due to limited sample size and complex terrain. These results indicate that real-time drone surveys, when integrated with distance sampling, can effectively correct for detection bias in density estimation of medium- to large-sized mammals. Future studies should apply advanced approaches such as Multiple Covariate Distance Sampling to account for variability in detection probability across survey conditions.

Ahn H, et al. J Vet Sci. 2026 ;27:e82. https://doi.org/10.4142/jvs.26130

Recent issues that have emerged in regard to raccoon dog (Nyctereutes procyonoides) include interaction with humans and disease transmission. Therefore, understanding their habitat characteristics and preferences is crucial in the effort to limit conflicts with humans. A total of thirteen raccoon dogs were captured from three regions in South Korea, each with distinct habitat characteristics. GPS trackers were attached for tracking the raccoon dogs’ movements. Utilizing GPS tracking data, Kernel Density Estimation (KDE), Minimum Convex Polygon (MCP), and Jacobs Index were applied to learn more about the habitat preferences of the raccoon dogs. According to the results, the habitat composition ratios for KDE and MCP showed that forests had the largest proportion. However, a habitat composition ratio similar to the land proportion of the area that they inhabit indicated that raccoon dogs had the ability to adapt to various habitats. Jacobs Index analysis revealed different habitat selection patterns compared to KDE and MCP, with forests showing neutral to negative selection despite comprising large proportions of home ranges. Our results highlight important methodological considerations when inferring habitat preferences from spatial data, suggesting that multiple analytical approaches provide complementary insights into animal space use.

This study was conducted as an effort to examine the association between mammalian species richness and environmental, anthropogenic, and bioclimate factors in the Province of Chungnam, Korea, using a stacked species distribution model (SSDM) approach. An SSDM model was constructed using an extensive dataset collected from 1357 mammal sampling points and their corresponding forest, geographical, anthropogenic, and bioclimatic information. Distance to forest edge, elevation, slope, population density, and distance to water channels were identified as important variables for determining species richness, whereas the impact of bioclimate variables was less important. The endemism map showed a strong correlation with species richness, suggesting the important role of endemic species. Overestimation was observed in areas with lower species richness. However, the findings of the study still demonstrated that valuable insights can be obtained through the use of the SSDM, which may be helpful to land managers, aiding in the effective management of wildlife habitats, particularly in regions with an abundance of species richness and endemism.

We found that barn swallow (Hirundo rustica) breeding occurs within close proximity to humans. An evaluation of barn swallow breeding frequency and the breeding success rate of swallows at research sites, which were buildings inhabited by humans and buildings where humans had previously resided, was conducted in order to establish a relationship between the location of barn swallow nests and human habitation and activity frequency. The results demonstrated that barn swallows often breed in human-inhabited buildings. No significant relationship was observed between the wall material and the direction of the wall and the type of building, whereas a much higher proportion of the nests were located near doors with a high level of human movement. In addition, no significant correlation was observed between the location of the nest and the distance from potential resources (food, water etc.), however, a statistically significant relationship was observed between the frequency of human activity measured through the video camera and the number of nests located at a certain distance. The average number of offspring and the reproductive success rate were higher in nests located within close proximity to human activity compared to nests not located within close proximity to human activity, suggesting that the presence of humans had a positive effect on reproduction. This study show that barn swallow nesting occurs in locations where there is a human influence and humans provide implicit protection of swallows from predation, which has a significant impact on breeding.

Mesopredators like Asian badgers, Raccoon dogs, and Wild boars in South Korea, where apex predators are extinct, share habitats, offering a unique environment to study their interactions and activity patterns. This study deployed 130 motion-sensor cameras across 11 regions to examine their temporal activity. Asian badgers and Raccoon dogs displayed bimodal activity patterns; Asian badgers were active before midnight (21:00–24:00), while Raccoon dogs were active after midnight (02:00–05:00). Wild boars exhibited a unimodal pattern, mainly active before midnight (20:00–22:00). Seasonal variations affected the activity times of Raccoon dogs and Wild boars but not Asian badgers. The presence of Wild boars influenced the activity of Asian badgers and Raccoon dogs. Specifically, Raccoon dogs' activity varied significantly depending on whether Wild boars or Yellow-throated martens were present. Asian badgers' activity also changed in response to Wild boars. However, Wild boars appeared less influenced by the presence of other mesopredators. This study highlights the complex dynamics of predator interactions in shared habitats.

The brood reduction hypothesis, which explains asynchronous hatching in birds, as an adaptation that enables selective survival of older nestlings when availability of food is unpredictable. This study was conducted in order to determine whether the brood reduction hypothesis can explain asynchronous hatching in passerines. Infrared cameras were installed inside nest boxes where great tits (Parus major) were attempting to reproduce in order to determine whether the parents practiced selective feeding of older nestlings. According to the results of the study, no significant difference was observed between the hatching order and the average number of feedings per nestling. In addition, when examining the distribution of food according to hatching order over time, every 30 min, beginning at 9 a.m., selective distribution of food to older nestlings was not observed. In conclusion, use of the brood reduction hypothesis, which supports selective provision of beneficial feeding of older and larger nestlings, to explain the asynchronous hatching of passerines is problematic, thus conduct of future studies focusing on other hypotheses in order to explain the asynchronous hatching of this passerine bird will be necessary.