Introduction Body colour plays a significant role in the lives of amphibians, whose interaction with solar radiation has important implications for their thermal biology and correlated survival rate (e.g., Terentiev, 1950; Childs, 1953; Vences et al., 2002; Sanabria et al., 2014; Stuart- Fox et al., 2017; Martínez-Freiría et al., 2020; Smith et al., 2021). Thus, studying amphibian body colour is useful to gain a more in-depth understanding of the phenotypic plasticity and ecological adaptability of these organisms (e.g., Boero, 2013; Kolenda et al., 2017). In recent decades morphological abnormalities, including those involving body colour, have become a common issue for almost all amphibian populations in Ukraine, apparently as a consequence of habitat degradation (Henle et al., 2017a; Reshetylo et al., 2019; Palamarenko, 2020), and it is important to document these and recognise their origins. Amphibians are known to be affected directly and indirectly by exposure to pollutants or land-use changes, which can result in internal and external morphological abnormalities (Marushchak et al., 2017; Henle et al., 2017a; Marushchak and Muravynets, 2018; Hegde et al., 2019). Of these, colour anomalies are just one group of skin morphology aberrations that were classified as Type S1 (“skin malformations”) by Nekrasova (2008). However, determining the origin of a particular anomaly Herpetology Notes, volume 14: 1239-1251 (2021) (published online on 29 September 2021) A GIS approach to the study of colour anomalies in amphibians of Ukraine reveals the deleterious effect of human impacts Oleksii Y. Marushchak 1,* , Oksana D. Nekrasova 1,4 , Volodymyr M. Tytar 1 , Nazar A. Smirnov 2 , Oleksiy V. Korshunov 3 , Mihails Pupins 4 , Galyna I. Mykytynets 5 , Arturs Skute 4 , Klaus Henle 6 , and Hinrich Kaiser 7 1 I.I. [Ivan Ivanovitch] Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Bohdana Khmelnytskogo Street 15, Kyiv 01030, Ukraine. 2 Chernivtsi Regional Local Lore Museum, Olga Kobylyans’koi Street 28, Chernivtsi 58002, Ukraine. 3 Department of Zoology and Animal Ecology, V.N. [Vasily Nazarovich] Karazin Kharkiv National University, Svobody Square 4, Kharkiv 61022, Ukraine. 4 Department of Ecology, Institute of Life Sciences and Technologies, Daugavpils Universitāte, Parādes iela 1a, Daugavpils 5401, Latvia. 5 Pryazovsky National Nature Park, Ivan Bohun Street 46, Melitopol 72300, Ukraine. 6 UFZ – Helmholtz Centre for Environmental Research, Department of Conservation Biology & Social-Ecological Systems, Permoserstraße 15, Leipzig 04318, Germany. 7 Department of Vertebrate Zoology, Zoologisches Forschungsmuseum Alexander Koenig, Adenauerallee 160, 53113 Bonn, Germany; and Department of Biology, Victor Valley College, 18422 Bear Valley Road, Victorville, California 92395, USA. * Corresponding author. E-mail: ecopelobates@gmail.com © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. Abstract. Our study provides a review of colour anomalies in amphibians from Ukraine during the 20 th and early 21 st centuries. Observations including melanism, flavinism, leucism, and blue axanthism were assembled from the published literature (1909– 2018) and during field surveys (2000–2017). Blue colouration was the most common abnormal variant (81.5%; n = 106), and colour anomalies were recorded in 13 of Ukraine’s 24 administrative regions (oblasts), mainly along the Dnieper River and in the Carpathian Mountains. The largest number of anomalies was found in the Poltava (26.5%) and Kyiv (20.4%) Oblasts. We also explored the relationship between abnormal colouration and environmental variables using a GIS framework. Correlations existed mainly with geographic location and temperature-related parameters (e.g., reference evapotranspiration), as could be expected for interactions of morphological or physiological anomalies. However, the Human Footprint, an integrated index of anthropogenic impact, was also important. The connection of colour anomalies and human activities shows once again the importance of amphibians as bioindicators for the early detection of pollution and other harmful effects in aquatic ecosystems. Keywords. Abnormal colouration, blue frogs, blue axanthism, leucism, albinism, Ranidae, Salamandridae, Bombinatoridae, Bufonidae, Human Footprint, pollution, bioindication