Biodiversity Informatics, 15, 2020, pp. 67-68 67 GENERAL THEORY AND GOOD PRACTICES IN ECOLOGICAL NICHE MODELING: A BASIC GUIDE Marianna Simões1,2, Daniel Romero-Alvarez2, Claudia Nuñez-Penichet2, Laura Jiménez2, Marlon E. Cobos2 1 Entomology Department, Centrum für Naturkunde, University of Hamburg, D‐20146 Hamburg, Germany 2 Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, KS, USA Abstract. Ecological niche modeling (ENM) and species distribution modeling (SDM) are sets of tools that allow the estimation of distributional areas on the basis of establishing relationships among known occur- rences and environmental variables. These tools have a wide range of applications, particularly in biogeogra- phy, macroecology, and conservation biology, granting prediction of species potential distributional patterns in the present and dynamics of these areas in different periods or scenarios. Due to their relevance and practi- cal applications, the usage of these methodologies has significantly increased throughout the years. Here, we provide a manual with the basic routines used in this field and a practical example of its implementation to promote good practices and guidance for new users. Key words— calibration area, geographical information system, Maxent, occurrence data, species distri- bution modeling, variable selection. Species distributions are understood to be deter- mined by three limiting factors: movement capaci- ties, abiotic conditions, and biotic interactions. The joint effects of these three factors have been summa- rized in the so-called BAM diagram (Soberón and Peterson 2005). The principle of ecological niche modeling (ENM) is to relate locations where a spe- cies is observed with the environmental characteris- tics of those locations, to estimate conditions that are favorable for the species and consequently its poten- tial geographical range (Peterson et al. 2011). Recent years have seen an explosion of interest in building models of environmental suitability for species based on presence, absence, and abundance data, to estimate conditions within which a species can maintain populations without immigration subsi- dies (i.e., the ecological niche; Peterson et al. 2011, Warren 2012). However, the employment, documen- tation, and understanding of the rationale for con- figurations used on such estimates have been poorly documented, detracting robustness from ENM stud- ies (Cobos et al. 2019, Warren 2012). Seeking to reduce mistakes, improve standard- ization, ensure consistency, and provide training on the application of these tools, we provide basic guide- lines on the building of ecological niche models. This document is the second in the series of manuals in the Biodiversity Informatics Training Curriculum to provide students and researchers interested in the field with a practical guide to construct ENMs. The first manual discussed some of the steps involved in cleaning biodiversity data, and included a practi- cal exercise (Cobos et al. 2018). Both manuals are intended to emphasize key theoretical and method- ological considerations. The present document and the associated man- ual are not intended as a detailed treatment of geo- graphical information systems, Maxent functions, or to present thorough guidelines (Araújo et al. 2019, Feng et al. 2019, Merow et al. 2013, Phillips et al. 2006, Phillips and Dudík 2008, Phillips et al. 2017); in fact, multiple free resources are available, and we are including references to many of them at the end of the manual. Rather, we focus on common practic- es and techniques that are used when estimating the ecological niche and the potential distribution of a species. Our goal is to provide a manual for educa- tional purposes, building capacity, and basic compre- hension for the broader audience exploring the field, similar to what has been developed for other model- ing approaches in the biological sciences (e.g., phy- logenetics: Hall 2013, O’Halloran 2014). Here, we are providing theoretical background and a practical exercise to estimate areas of environmental suitabili- Biodiversity Informatics, 15, 2020, pp. 67-68 68 ty for our chosen model species: the poison dart frog, Dendrobates auratus. The full manual and datasets used for the exercise are available at http://hdl.handle.net/1808/30276. Acknowledgments We thank the broader University of Kansas Eco- logical Niche Modeling group, which was the context within which we developed this manual. We thank A. Townsend Peterson for comments on an earlier ver- sion of the manuscript. Competing Interests The authors have declared that no competing inter- ests exist. References Araújo, M. B., R. P. Anderson, A. M. Barbosa, C. M. Beale, C. F. Dormann, R. Early, R. A. Garcia, A. Gui- san, L. Maiorano, B. Naimi, R. B. O’Hara, N. E. Zim- mermann, and C. Rahbek. 2019. Standards for distri- bution models in biodiversity assessments. Sci. Adv. 5(1):eaat4858. Cobos, M. E., L. Jiménez, C. 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