Ecological Niche Modelling Reveals the Peculiarities of Ecological Disjunction Between Two Sympatric Racerunners in Kazakhstan: Eremias lineolata (Nikolsky, 1897) and Eremias scripta (Strauch, 1867)

Authors: Marina A. CHIRIKOVA* and Dmitry V. MALAKHOV

Institute of Zoology, Committee of Scientific Ministry of Science and Higher Education, Al-Farabi 93 Akademgorodok, Almaty 050060,


The ecological-niche models for two sympatric species, Eremias lineolata (Nikolsky, 1897) and Eremias scripta (Strauch, 1867), reveal evidence of spatial and temporal disjunction in the actual niches of both species. Eremias lineolata demonstrates a wide range of adaptations and, at the same time, has a greater need for winter precipitation and minimal temperature than E. scripta. Possible explanations for the thermal diversity of both species are provided. Thermal variables (monthly temperatures, monthly solar radiation, etc.) are traditionally important for ectotherm animals.

Interestingly, as many as half of the key variables in both species are related to different aspects of environmental water balance (precipitation, air humidity, vapor pressure). There are several ways in which moisture may impact the lizard’s life cycle. Soil humidity is related to soil temperature and may be important during winter hibernation. In summer, soil humidity may support successful embryogenesis. Precipitation during the warm months is a key factor in maintaining the moisture content of the soil. In winter, snow cover provides a better thermal balance of the soil’s top layers where winter shelters are housed. Ecological niche modeling (ENM) is an interdisciplinary approach combining the geographical, climatic, ecological, and biological aspects of the wellbeing of species. This interdisciplinary approach lifts biological studies onto a new, integrative level, providing a comprehensive view on species biology and answering the questions that might not be answered if the traditional methods for studying animals were used alone.

Keywords: ecology, Kazakhstan, niche modelling, racerunners,
species distribution

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