Distribution Patterns and Ecological Niches of the Red-tongued Pit Viper (<i>Gloydius ussuriensis</i>) and the Central Asian Pit Viper (<i>Gloydius intermedius</i>) in Cheonmasan Mountain, South Korea

Abstract

Studies on the distribution of species are important to understanding the interspecific ecological niche and habitat selection through geographic environmental information. Particularly, vipers in the same genus have been an important topic because they show differences in the preferred geographical environment, depending on the distance of the phylogenetic relationship. This study investigated the geographical environment of red-tongued pit vipers (Gloydius ussuriensis) and Central Asian pit vipers (Gloydius intermedius) in the mountainous area, Cheonmasan Mountain County Park, South Korea, from April 2012 to October 2014, to understand the relationships among their habitat characteristics and ecological niche. Red-tongued pit vipers mainly lived in low altitude, wet valley areas with a low solar reflectance, while Central Asian pit vipers inhabited high altitude, dry land with large amounts of sunshine. As a result, our study supports that the ecological niche of red-tongued pit vipers and Central Asian pit vipers, inhibiting in Cheonmasan Mountain was overlapped low according to the majority of geographical environmental variables. The differentiated diet preference might be took into consideration as one of the potential key factors to the ecological niche differentiation among two species.

Effects of environmental factors and intraspecific niche overlap on the body and ecological characteristics of red-tongued pit vipers (Gloydius ussuriensis)

“…Information about niches is useful for understanding the biogeographical range and evolution of species [14,15] . Niches can be broadly quanti ed along the axes of food, space, and time; such a quanti cation allows the analysis of intra-and interspeci c niche overlap and niche separation [16,17] . The individuals of the same species with similar age and head and body morphology exhibit a high degree of niche overlap because they share ecological resources, such as food and habitat [1,18,19] .…”

“…Numerous studies focusing on the different aspects of G. ussuriensis, including studies on morphology [23,[28][29][30] , genetic diversity [31,32] , sexual dimorphism of island populations [33] , food sources [34,35] , toxicity [36] , intraspeci c competition [15,17] , and conservation [37] , have been conducted. However, studies focusing on the body condition of and intraspeci c competition among G. ussuriensis individuals have not yet been conducted.…”

“…Meanwhile, the body condition of G. ussuriensis was unaffected by PC2, which re ects precipitation-related variables. Such a nding is attributed to the greater in uence of altitude and ambient temperature than water sources on maintaining the body condition of G. ussuriensis [15,17,26] . Moreover, researchers who investigated the effects of the surrounding environment on snakes reported that precipitation-related variables had lesser effect on the range, activity, or population size of snakes than other geographic variables [15,61,65] .…”

“…Altitude was found to be the geographic variable with signi cant effects on the health of G. ussuriensis. Among the environmental variables, altitude had the greatest effect on the range of three Viperidae species living in Korea, and interspeci c ecological niches are delimited by the preferred altitude range of each species [15,17,37] . For example, G. ussuriensis mainly inhabits low-altitude mountainous forests below 500 m, G. blomho i usually inhabits low-altitude rivers and grasslands below 300 m, and G. saxatilis typically inhabits high-altitude mountainous forests above 400 m [27,47] .…”

“…For example, G. ussuriensis mainly inhabits low-altitude mountainous forests below 500 m, G. blomho i usually inhabits low-altitude rivers and grasslands below 300 m, and G. saxatilis typically inhabits high-altitude mountainous forests above 400 m [27,47] . Due to differences in their preferred environments, an interspeci c niche separation by altitude (PI: 0.27) and habitat (PI: 0.26) was determined between G. ussuriensis and G. saxatilis [17] . On the other hand, since the ecological habitats of the G. ussuriensis specimens examined in this study were similar among different sexes and ages, there was a very high degree of intraspeci c niche overlap by altitude (PI: 0.97) and habitat (PI: 0.99).…”