Species' Traits As Predictors of Avoidance Towards Roads and Traffic
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Species’ traits as predictors of avoidance towards roads and traffic Article Accepted Version Creative Commons: Attribution-Noncommercial-No Derivative Works 4.0 Duffett, D., D'Amico, M., Mulero-Pázmány, M. and González- Suárez, M. (2020) Species’ traits as predictors of avoidance towards roads and traffic. Ecological Indicators, 115. 106402. ISSN 1470-160X doi: https://doi.org/10.1016/j.ecolind.2020.106402 Available at http://centaur.reading.ac.uk/90004/ It is advisable to refer to the publisher’s version if you intend to cite from the work. See Guidance on citing . To link to this article DOI: http://dx.doi.org/10.1016/j.ecolind.2020.106402 Publisher: Elsevier All outputs in CentAUR are protected by Intellectual Property Rights law, including copyright law. Copyright and IPR is retained by the creators or other copyright holders. Terms and conditions for use of this material are defined in the End User Agreement . www.reading.ac.uk/centaur CentAUR Central Archive at the University of Reading Reading’s research outputs online 1 Title: Species’ traits as predictors of avoidance towards roads and traffic 2 3 Authors: Daniela Duffetta,†, Marcello D’Amicob,c,†, Margarita Mulero-Pázmányd, Manuela 4 González-Suáreza,* 5 6 Affiliations: 7 a Ecology and Evolutionary Biology, School of Biological Sciences, University of Reading, 8 Reading, RG6 6AS, UK 9 b THEOECO, CIBIO-InBIO, University of Porto, Vairão, 4485-661, Portugal 10 c School of Agriculture, CEABN-InBIO, University of Lisbon, Lisbon, 1349-017, Portugal 11 d School of Biological and Environmental Sciences. Liverpool John Moores University, UK 12 * Corresponding author: [email protected] 13 † These authors contributed equally 14 15 Declarations of interest: none. 16 17 Abstract 18 Road-networks and their associated motorized traffic pose a threat to biodiversity and 19 ecosystems, with different groups of species exhibiting different avoidance responses. The 20 often species-specific nature of these behavioural responses to roads and traffic suggest that 21 morphological, ecological, life-history and behavioural traits could be useful in explaining 22 and predicting these responses. Trait-based predictive models have been used to assess 23 extinction risk, land use impacts, and road mortality. Here we present the first, to our 24 knowledge, test of their potential to address animal road avoidance. We studied the fleeing 25 responses and spatial distribution in relation to roads of diverse ungulate species across three 26 South African protected areas. Our results show that smaller, solitary species with non- 27 grazing food habits are more likely to flee in response to presence of a vehicle. None of the 28 tested traits showed a clear relationship based on biological hypotheses with initial distance to 29 roads and tolerance distance to vehicles (used to describe behavioural avoidance towards 30 roads and vehicles, respectively). However, we found significant effects that supported 31 proposed methodological hypotheses. Our results show the potential to use traits as indicators 32 of vehicle and traffic avoidance. Obtaining behavioural avoidance data in the field for many 33 species and areas can be time consuming, but here we show it may be possible to use 1 34 available trait data to generally predict species responses. This could be useful for initial 35 species risk assessments. 36 37 Keywords: African ungulates, ecotourism, flight response, road avoidance, road ecology, 38 traits-based model. 2 39 1. Introduction 40 The rapid and global expansion of road infrastructures and associated motorized traffic 41 pose a great threat to biodiversity and ecosystems worldwide (Laurance et al., 2014; Ibisch et 42 al., 2016), even within protected areas (Garriga et al., 2012; Monz et al., 2016). Roads and 43 traffic affect wildlife by causing mortality due to collisions with vehicles (Coelho et al., 2008; 44 D’Amico et al., 2015; González-Suárez et al., 2018) and fragmenting and destroying habitat 45 (Forman, 2000; Eigenbrod et al., 2008). The latter include direct loss due to road 46 construction, as well as indirect losses via traffic emissions (e.g. noise, light, chemical 47 pollution) deteriorating habitat quality within road-effect zones (Forman and Deblinger, 2000; 48 Laurance et al., 2014). The combined action of increased mortality by roadkill and avoidance 49 behaviours towards road-effect zones can produce barrier effects, which can lead to 50 population fragmentation, genetic isolation and even local extinction (Grilo et al., 2012; Ceia- 51 Hasse et al., 2018). 52 Distinct groups of species often exhibit different avoidance responses within road-effect 53 zones, including: road avoidance (which includes road-surface avoidance and habitat-gap 54 avoidance), traffic-emissions avoidance, and vehicle avoidance (Jaeger et al., 2005; D’Amico 55 et al., 2016). Road-surface avoidance is common among small-sized species, such as rodents, 56 that avoid the hostile conditions of the road surface (e.g. materials, temperature; McGregor et 57 al., 2008; Brehme et al., 2013). Canopy birds and arboreal mammals usually exhibit habitat- 58 gap avoidance caused by both natural and artificial gaps in the vegetation (Laurance et al., 59 2004; Chen and Koprowski, 2016). Traffic-emissions avoidance is probably the most 60 common behavioural response to roads and traffic, with different species responding to 61 different types of emissions. For example, nocturnal mammals tend to avoid street lights 62 (Francis et al., 2015), many songbirds avoid traffic-related noise (including experimental 63 phantom roads; McClure et al., 2013) and some ungulates preferentially graze away from 64 linear infrastructures due to road dust (Ndibalema et al., 2008). Finally, vehicle avoidance 65 mostly affects species that approach roads but still react to oncoming vehicles, a reaction 66 observed in several scavenger species (Rytwinski and Fahrig, 2012). 67 The species-specific nature of behavioural responses to roads and traffic suggests that 68 some morphological, ecological, life-history and behavioural traits could be useful to explain 69 and predict these responses. Although previous studies have postulated that species’ traits 70 should produce, in turn, species-specific variations in animal abundance related to roads and 71 traffic (Fahrig and Rytwinski, 2009; Rytwinski and Fahrig, 2011, 2012, 2013; Francis, 2015), 72 no previous research, to our knowledge, has directly investigated the relationship between 3 73 species’ traits and behavioural responses to roads and traffic, and the potential of applying 74 trait-based model to assess avoidance responses to roads and traffic/vehicles. Past studies 75 have considered how species’ traits influence roadkill probability (Ford and Fahrig, 2007; 76 Barthelmess and Brooks, 2010; Cook and Blumstein, 2013; D’Amico et al., 2015; Santos et 77 al., 2016), but only recently the full potential for using trait-based models in Road Ecology 78 has started to be considered, and for now has only been explored for estimates of road- 79 associated mortality (González-Suárez et al., 2018). 80 Our study addresses this knowledge gap by exploring the value of diverse species’ traits 81 to understand ungulate behavioural responses to roads and traffic. We considered several 82 species’ traits reflecting different biological hypotheses (Table 1) based on the general 83 assumption that roads and vehicles can be perceived as a danger, similar to predators, by 84 ungulates (Frid and Dill, 2002; Lima et al., 2015). We hypothesize an effect of morphology 85 on avoidance responses, because smaller species have been found to be more cautious 86 towards potential predators than larger species (Berger and Cunningham, 1988). Research has 87 shown that ungulates such as pronghorns Antilocapra americana in North America (Gavin 88 and Komers, 2006) and Tibetan antelopes Pantholops hodgsonii in Asia (Lian et al., 2011) 89 can respond to vehicles as if these were predators. Species with relatively larger brains have 90 greater learning and cognitive capacity (Shultz and Dunbar, 2006), thus, we propose they may 91 be able to realize that vehicles are not actual predators (within protected areas) and show no 92 or limited avoidance responses. Foraging habits have been shown to affect anti-predatory 93 responses; the spatial distribution of browsing ungulates, but not of grazing species, has been 94 shown to change in response to predators (Valeix et al., 2009), thus, we predict browsing 95 species will avoid roads and vehicles more often. Longevity may also be important because 96 long-lived species have greater learning capacities (Street et al., 2017) and their longer 97 lifespan can allow them to learn by experience that vehicles are not predators. The trade-off 98 between investment in reproduction and survival (Promislow and Harvey, 1990) proposes that 99 slow-breeding species will invest more in self-maintenance and thus, should be more cautious 100 towards potential predators (or roads and vehicles) than fast-breeding species. Finally, solitary 101 species have been shown to be more wary of potential predators than gregarious species 102 (Hunter and Skinner, 1998), thus we predict solitary animals will show higher avoidance. As 103 alternative hypotheses, we considered methodological effects, mostly associated to 104 detectability, that could also result in association between species’ traits and behavioural 105 responses (all biological and methodological hypotheses are summarized