This study was conducted from February to November, 2022. Study sites were selected by three inland (Yeoncheon-gun, Gyeonggi-do, Pyeongchang-gun, Gangwon-do, Yeongcheon-si, Gyeongsangbuk-do) and one island (Jeju-si, Jeju-do). The purpose of this study...
This study was conducted from February to November, 2022. Study sites were selected by three inland (Yeoncheon-gun, Gyeonggi-do, Pyeongchang-gun, Gangwon-do, Yeongcheon-si, Gyeongsangbuk-do) and one island (Jeju-si, Jeju-do). The purpose of this study is to compare the difference of fire-bellied toad by region, through body color(analysis on the back and belly color), and body mass(SVL, BW). The effect on these differences were analyzed using the environmental factors (mean temperature, precipitation, and humidity) on each region.
Sites with water system connected to the forests and where farmland is placed were chosen, and were also selected so that they were evenly throughout the Korean peninsula. Based on the water system in each site, fire-bellied toads living in riversides, valleys and farmland were captured, and it was terminated when 50 individuals were captured at each site. The field investigation was conducted by line census and point census in every site. As an exception, in Jeju, which is site (D), pit-fall trap was additionally used. Since site (D) is forming a volcanic topography, water is collected in the river only in the case of rain. Moreover, due to low activity compared to the toads that live in the inland, there were some difficulty in capturing through visual investigation, so additional traps were used. All of the captured fire-bellied toads were measured for snout-vent length (SVL) and body weight (BW) each by using a ruler and an electronic scale. After the measurement, the picture of the back and belly part were taken placed on a white background.
For the environmental factors, the ASOS(Automated Synoptic Observing System) device data closest to each site were used. Site (A) was matched to Cheorwon(95) device, site (B) to Jeongseon-gun(217) device, site (C) Yeongcheon(281) device, and site (D) to Jeju(184). Three-year data(2019-2021) of each ASOS device were collected, and data from November to March, the hibernation period of the fire-bellied toad, were excluded and then analyzed. As a result of the environmental factor analysis, the mean temperature at each site was high in the order of (D)>(C)>(A)>(B), the mean precipitation in the order of (D)>(A)>(C)>(B) and the mean humidity was high in the order of (A)>(D)>(B)>(C).
50 fire-bellied toad (30 female, 20 male) were captured in site (A), site (B) also 50 individuals (33 female, 17 male), site (C) also 50 individuals (21 female, 29 male), and in site (D) 2 fire-bellied toads(unidentified by gender) were captured. As a result of the comparison of the total SVL and BW of the non-gendered toads, the mean SVL was 5.16 ± 0.03 cm (n=150, range=4.4~6.0 cm) and the mean BW was 9.263 ± 0.163 g (n=150, range=4.12~21.58 cm). One-way analysis of variance was conducted to find out the difference between the mean SVL and BW for each site, but there was no significant difference between both SVL and BW.
In order to analyze whether SVL and BW means differ according to gender, independent sample t-test was conducted on all individuals, female and male SVL, BW by region. The mean SVL of females for the total population was 5.16 ± 0.04 cm (n=84, range=4.4-6.0 cm), and the mean SVL of males was 5.05 ± 0.03 cm (n=66, range=4.4-5.6 cm). Mean BW for the female was found to be 9.836 ± 0.242 g (n=84, range=6.33), and mean BW of the male was 8.533 ± 0.171g(n=84, range= 4.12~11.3). There was no significant difference in the mean SVL of males and females in both (A) and (B) (p>0.05), whereas in the case of (C), there was a statistically significant difference between the mean SVL of females and males. In terms of BW, it was confirmed that there was no significant difference in the mean of males and females at both (A) and (C) (p>0.05), whereas for (B), there was a statistically significant difference between the mean BW of females and males.
As a result of body color analysis, the mean R, G, and B values of both the back and belly were higher than in other regions in site (B), indicating a statistically significant difference (p<0.05). For site (A) and site (C), the difference by color was confirmed differently. The mean R, G, and B values of the back were higher in (A) than in (C), and in R value of the belly was higher in (C) than in (A), while the mean G and B value was higher in (A) than in (C).
Pearson's correlation analysis results showed that the mean RGB value of the back and belly had a significant positive correlation (r2=0.3589) at the level below p-value 0.01.
It was confirmed that the environmental factors of each site may have affected the change in body color of the fire-bellied toad, and among them, temperature and precipitation were in line with the results of body color analysis. In the future, we plan to supplement the research results and increase the reliability by securing additional populations of fire-bellied toads at site (D).
The results of this study are basic ecological data for Korean fire-bellied toad and are intended to be provided as basic data for Korean amphibian ecological research. It is expected to be used not only in monitoring studies that can determine the correlation between environmental changes by region due to climate change, but also in research on Chytridiomycosis and amphibian ecological restoration through Korean fire-bellied toads.
Keywords : Body color analysis, Body mass, Bombina orientalis, Environmental factor, Regional variation