Roads and wildlife: the need for evidence-based decisions; New Zealand bats as a case study

Abstract

Roads and associated land transport activities can affect a wide range of indigenous terrestrial vertebrate species. National legislation, particularly the Resource Management Act 1991, requires that developers 'avoid, remedy or mitigate' the adverse environmental effects of their activities. How these effects are identified and managed in New Zealand varies because regulators and land transport contractors deal with these issues on a case-by-case basis. In recent years, the effects of new road projects on long-tailed bats (Chalinolobus tuberculatus) have been receiving attention. In this review, we summarise evidence on likely road infrastructure impacts on bat populations and the efficacy of mitigation approaches, used both internationally and in New Zealand. Our findings indicate that most mitigation methods have little, if any, scientific evidence of their effectiveness. We recommend that such evidence is essential to guide investment in mitigating road effects on bats in New Zealand. Given that such evidence is rare, future investment should be guided by an adaptive management framework that is justified by strong, inferential, evidence-based logic, and accompanied by robust, appropriately designed monitoring planned, in advance, to allow an objective assessment of a method's effectiveness in mitigating an impact. Because such monitoring may be beyond what a single development project can realistically achieve, we suggest the development of a collaborative funding model for supporting the testing and development of mitigation methods. This work is likely to have a significant influence on the future planning and design of road infrastructure projects to minimise the impacts on bats and, more generally, on any native wildlife populations under threat from infrastructure development.

Landscape and Species Traits Co-Drive Roadkills of Bats in a Subtropical Island

“…The subregions II, III, and IV had 15, 9, and 6 species recorded. The proportions of victim species richness to the known species richness of each elevational subregion (17,17,16, and 17 species for the subregions I, II, III, and IV, respectively) differed significantly among the four subregions (X 2 = 18.1, d.f. = 3, p < 0.001, test for equality of proportions).…”

“…Bats are usually considered as good indicators of environmental changes due to their strong associations with habitats and high sensitivity to disturbances [10], including mortality due to vehicle collision [11]. Although bat roadkills are only reported from a few countries [6,[12][13][14][15][16], the fact that bats and viceless can be found globally suggests that it is an overlooked threat to global bat populations. Incidence rate and spatial patterns of bat roadkills have been demonstrated to be associated with roadside microhabitats, landscape features, for example, distance to critical resources, and roadway designs [6,14,[17][18][19].…”

Lighting trends reveal state of the dark sky cloak: light at night and its ecological impacts in Aotearoa New Zealand

“…Sustained avoidance of ALAN may culminate in negative effects on body condition and reproductive ability (Smith et al 2017). Addressing ALAN's long-term impacts is vital for developing effective strategies to avoid or mitigate the impacts of ALAN on bats (Jones et al 2019), particularly for management plans.…”

Optimising the cost of roadkill surveys based on an analysis of carcass persistence

“…Accurately measuring and quantifying rates of roadkill is a fundamental part of understanding which ecological and environmental factors are the most important in contributing to roadkill. There has been a call to standardise methods of roadkill surveys so that results are easily comparable across different landscapes, ecological systems, and road infrastructure configurations (Collinson et al, 2014;Jones et al, 2019;Ogletree and Mead, 2020).…”