COMMENTARY Neglected effects of transport corridors: attractiveness to wildlife and role in conservation planning F. Morelli Faculty of Environmental Sciences, Department of Applied Geoinformatics and Spatial Planning, Czech University of Life Sciences Prague, Prague, Czech Republic Correspondence Federico Morelli, Faculty of Environmental Sciences, Department of Applied Geoinformatics and Spatial Planning, Czech University of Life Sciences Prague, Kam yck a 129, CZ-165 00 Prague 6, Czech Republic. Tel: +420774232640. Email: fmorellius@gmail.com doi: 10.1111/acv.12372 Anthropogenic features, such as human settlements, build- ings, and roads and railway networks, are conspicuous ele- ments in any type of landscape worldwide (Grimm et al., 2008). These human-made structures also represent a chal- lenge for wildlife in their environments. In recent decades, many studies have focused on the negative effects of human-made structures on plants and animals. In particular, linear transport infrastructures are often used as a study case, constituting a novel branch of urban ecology, called road ecology (Forman et al., 2003), and the ecological effects of roads and railways on vertebrate wildlife have been relatively well documented in the scientific literature (e.g. Forman & Alexander, 1998). The primary ecological effects on wildlife are negative, and are linked to habitat loss, increasing barrier effects, habitat fragmentation, direct mortality by collision with traffic, and direct or indirect disturbance, which alter habitat suitability for many species (Forman et al., 2003). Overall, the number of documented negative effects of roads/railways on wildlife outnumber the positive effects (Fahrig & Rytwinski, 2009). Only a few studies have high- lighted that some species are attracted by human-made struc- tures and are able to exploit them. When animals attracted by roads or railways gain access to a resource, and they have the ability to avoid the risk represented by vehicles, this can provide a net positive effect of linear infrastructures (Fahrig & Rytwinski, 2009). We explored in a review paper some of these positive interactions where road and railway networks attract bird species, mainly offering foraging habi- tats (Morelli et al., 2014). However, wildlife attracted to these habitats do face the threat of collisions on roads and railways. Sometimes, ‘easily accessible food’ is not a net benefit for the species exploiting such alternative resources. The role that human transportation corridors, such as rail- way networks, can play in the distribution of wildlife species is often overlooked when it comes to assessing conservation issues. In order to obtain a better understanding of the over- all effects of human-made structures on wildlife and biodi- versity conservation, it is necessary to evaluate all types of interactions: negative effects (fragmentation, disturbance, and railway-kill risks), positive effects (foraging opportunities, refuges in railway verges), and combinations of both (for instance attractiveness followed by an increase in the risk of railway kills). An excellent example of this is provided in the study by Gangadharan et al. (2017). In this study, the authors provide a scholarly analysis of how the deposition of grain dispersed by transport trains can attract charismatic species, such as the grizzly bear Ursus arctos horribilis, increasing the risks of railway kills of these animals. As the authors pointed out, ‘vehicle-borne attractants are rarely stud- ied in the literature despite their likely ubiquity along trans- portation corridors’ (Gangadharan et al., 2017). What also emerges from the study is that additional explorations of the potential effects (not only negative, but also positive ones) between transportation corridors and animals may contribute significantly to both understanding conservation of wildlife and reducing the risks to humans. Gangadharan et al. (2017) showed that in just 134 km of railway, an average of 64.8 tons of grain can be dispersed per year during the months of April–October, with an addi- tional 44.6 tons of grain deposited on average during the winter period, providing an important food resource for griz- zly bears. These findings offer an explanation for why trains are one of the most widely recognized causes of mortality for these animals in Banff and Yoho National Parks (Bertch & Gibeau, 2010). Furthermore, the authors highlight that, with high probability, the problem of vehicle-borne food attractants for wildlife will increase with the expansion of road and railway networks globally (Dulac, 2013). For this reason, and considering that the mortality caused by railways can reduce population viability of wildlife species (Forman et al., 2003), and increase risk for humans to be involved in incidents, it is crucial to identify the locations and times when attractants can be deposited (hotspots). Even though the prediction of hotspots of the attractant was not the full focus of this study, an additional merit of the paper by Gangadharan et al. (2017) is that it provides a valuable Animal Conservation 20 (2017) 401–402 ª 2017 The Zoological Society of London 401 Animal Conservation. Print ISSN 1367-9430