diversity Article Predicting the Potential Distribution of Non-Native Mammalian Species Sold in the South African Pet Trade Ndivhuwo Shivambu , Tinyiko C. Shivambu and Colleen T. Downs *   Citation: Shivambu, N.; Shivambu, T.C.; Downs, C.T. Predicting the Potential Distribution of Non-Native Mammalian Species Sold in the South African Pet Trade. Diversity 2021, 13, 478. https:// doi.org/10.3390/d13100478 Academic Editors: Michael Wink and Jordi López-Pujol Received: 6 August 2021 Accepted: 25 September 2021 Published: 29 September 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). DSI–NRF Centre for Excellence in Invasion Biology, and Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu–Natal, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa; ndivhuwomaligana@gmail.com (N.S.); shivambucavin@gmail.com (T.C.S.) * Correspondence: downs@ukzn.ac.za Abstract: The pet trade is one of the main pathways of introduction of several mammals worldwide. In South Africa, non-native mammalian species are traded as pets, and so far, only four of these species are considered invasive. We used a list of 24 companion mammalian species compiled from a previous study. We selected a subset of 14 species for species distribution modeling (SDM) based on their trade popularity, invasion history and potential economic and socio-economic impacts. We aimed to estimate their potential distribution using their distribution records. Our SDM indicated that climate in South Africa was suitable for most traded species. However, commonly and easily available species had the broadest areas of suitable climates, such as house mice (Mus musculus) and Norwegian rats (Rattus norvegicus). In addition, the model with a human footprint suggested a high risk of invasion for Norwegian rats but less for house mice distribution. This assessment suggests the need of strict trade regulations and management strategies for pet mammals with broader suitability, which are already invasive, and most available for sale. In addition, our results provide a baseline approach that can be used to identify mammalian pet species with a potential risk of invasion so that urgent preventive measures can be implemented. Keywords: human footprint; species distribution modeling; invasive species; introduction pathway; impact 1. Introduction Several mammalian species have been introduced in South Africa and other countries for different purposes, including pest control, research, food, fur markets, game, hunting, zoo, and as pets [1–6]. Mammalian species are among the most successful invaders world- wide, and their success as biological invaders has mostly been linked to their ability to breed successfully, extensive physiological tolerance, association with humans, broad habi- tats, and diets [1,7–9]. Invasive mammalian species are associated with negative impacts on agriculture, human health, infrastructure, native fauna and biota in general [9–13]. It is vital to investigate the invasion history and potential distribution of non-native species to prevent them from becoming invasive and causing impacts. Studies have sug- gested that matching the climate between the native and non-native areas of a species is essential in identifying the invasion potential for a species [14,15]. Species distribu- tion modeling (SDM) is a widely used tool to predict potentially suitable areas where non-native species may establish and become invasive if introduced into favorable envi- ronments [16–18]. Species distribution modeling is also known as a bioclimatic envelope, ecological niche modeling or habitat suitability modeling, which uses an organism’s occurrence records com- bined with geographical and environmental variables to predict species suitability [19–23]. The SDM has been applied in a range of fields, including biodiversity conservation and wildlife management [22,24,25], climate change [26], species extinction assessment [27], risk assessment [28–30] and effects of human footprint [31,32]. Distribution modeling can Diversity 2021, 13, 478. https://doi.org/10.3390/d13100478 https://www.mdpi.com/journal/diversity