Abstract | Are we monitoring in the dark? Implementation of a bat framework on a roading project in Hamilton, New Zealand

Do roads pose a threat to NZ’s bat population? If so, we need to understand how these and other linear infrastructure are affecting them and whether strategies in place to mitigate these effects actually work. This requires knowledge about bat population dynamics, distribution and behaviours. Most monitoring undertaken in NZ to date does not effectively quantify the impacts of roads on bats, meaning we remain largely in the dark when it comes to their management.

To address this problem we helped develop a framework to guide projects on identifying and reducing adverse impacts of linear infrastructure on bats. During the framework development we found ourselves limited by a lack of information quantifying the impacts (and associated interventions) on bats from roads.

We were confronted with fundamental challenges around how to provide sound monitoring guidance in the absence of supporting evidence, while encouraging infrastructure providers and regulatory decision makers to value the importance of its implementation. Returning to basic monitoring principles and concentrating on current best practice, we developed monitoring guidance and a framework for adaptive management, with the latter forming the backbone of the approach.

The framework was first implemented on the Southern Links road project in Hamilton, NZ where a long-term long-tailed bat monitoring programme has been implemented on behalf of Hamilton City Council and the NZ Transport Agency. The first year of pre-construction monitoring used emerging thermal imaging technology along with acoustic monitors. This provided meaningful and insightful data on bat behaviour, however identifying exact locations of roosts were not being achieved, which was a key objective of the monitoring. As such, the scope of the second year of monitoring was updated to include capture and radio tracking of bats using a unique and novel lure technique to locate roosts and understand foraging routes.

Bio | Fiona Davies

Fiona Davies is a Principal Environmental Scientist at AECOM with over 16 years’ experience project managing ecological issues on large scale projects in NZ and the UK. She is passionate about ensuring NZ ecology is considered in every step of project development and uses her position within a global consultancy to help implement change. She has extensive experience with the ecological assessment of streams, ecological monitoring, mitigation and management of projects (with a particular focus on NZ bats). She has worked for clients in the residential development, roading, wastewater treatment plant, water storage, linear infrastructure and the landfill sectors. Fiona frequently gives advice on the potential ecological impacts of projects. Fiona was a key member on the project team that developed and researched a national framework to manage the effects of land transport activities on New Zealand’s endemic bat populations. She is currently the ecological lead for the programme of ecological monitoring and management for the Southern Links roading project in Hamilton, NZ. This includes the development of a terrestrial restoration strategy to compensate for the loss of indigenous gully vegetation.