Turning complex ecological challenges into clear action

We help clients understand, manage and monitor bat activity throughout the lifecycle of a project. From vegetation clearance and impact assessment to consent requirements and long-term monitoring, we provide clear, evidence-based advice tailored to each project. We focus on delivering practical solutions that protect bat populations whilst helping projects move forward with confidence.

20 years experience

Specialist expertise

Clear communication

Evidence based

What sets us apart

Mark Roper is a senior ecologist with more than 20 years of experience and specialist expertise in bat ecology, helping organisations make informed decisions in complex environmental contexts. Working across diverse project types, he identifies ecological risks early, reduces uncertainty, and develops practical pathways forward. His approach is evidence-based, aligned with recognised bat roost protocols, and focused on delivering outcomes that are scientifically robust, proportionate, and workable in practice. Whether you need specialist advice, project support, or guidance on next steps, we bring practical ecological expertise to help turn complexity into action.

Our consultancy follows established bat roosting protocols to ensure consistent, compliant, and evidence-based practice.

  • Acoustic surveys are at the core of what we do. Using specialised bat detectors, we monitor bat activity across sites to determine whether bats are present, how they are using the landscape, and where activity is concentrated. These surveys provide the robust data needed to inform project planning, impact assessments, monitoring programmes, and management decisions.

  • If your project involves tree removal, we assess trees for Potential Roost Features (PRFs) that could be used by bats. This helps identify where bats may be present and highlights any trees that require further investigation before works proceed.

  • Where Potential Roost Features are identified, we help clients understand which trees may be of greatest importance to bats. By combining survey results with ecological expertise, we provide the information needed to make informed decisions about tree retention, project design, and risk management.

  • Before trees containing Potential Roost Features are removed, we undertake targeted inspections to determine whether bats are present. Depending on site conditions and project requirements, this may include acoustic monitoring, thermal imaging, endoscope inspections, and visual assessments to ensure works can proceed responsibly and in accordance with consent requirements.

  • Following tree removal, we undertake final inspections of felled trees to confirm that bats are not present within identified roost features. This may involve visual inspections and handheld bat detection surveys, providing an additional layer of confidence and compliance during project delivery.

  • We develop Bat Management Plans that outline the survey, monitoring, mitigation and management actions required for a project. These plans provide a clear framework for managing potential impacts on bats and ensuring regulatory requirements are met throughout project delivery.

  • We design and implement monitoring programmes that assess how activities may affect bat populations and habitat use over time. By combining robust survey design with acoustic monitoring, we generate the data needed to evaluate project effects, measure outcomes, and support evidence-based decision making.

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Case study 1: Keeping pekapeka safe on the Wairoa river

  • Flood protection works along the Wairoa River required the removal of a stand of mature exotic trees. Trees that, as it turned out, long-tailed bats (Chalinolobus tuberculatus) were actively using. New Zealand’s only surviving land mammals and classified as Threatened - Nationally Critical, long-tailed bats (pekapeka) face serious risk when roost trees are felled without proper survey and management. HBRC needed to know whether bats were present, which trees posed the greatest risk, and how to proceed with felling without causing harm.

  • We implemented all five steps of the DOC Bat Roost Protocols across this project. First, we deployed nine acoustic bat detectors along the Wairoa River for 23 survey nights, recording over 571 long-tailed bat echolocation calls across eight of nine survey sites, confirming bats were actively using the area. We then conducted a Bat Roost Potential Assessment (BRPA), walking the entire works footprint to visually assess every tree proposed for removal, identifying those with potential roost features (PRFs) such as cavities, cracks, and loose bark. Immediately prior to felling, we deployed detectors again over two consecutive valid survey nights, used a thermal camera for roost watches, and supervised the felling and post-felling inspection of every tree on site. All acoustic data was contributed to the DOC National Bat Database.

  • All trees were successfully felled and no bats were harmed. Our pre-felling acoustic monitoring allowed works to proceed with confidence, and our on-site supervision ensured that every felled tree was inspected before removal from site. The project added 571 new long-tailed bat call records to the national database, strengthening knowledge of bat distribution in the upper North Island.

  • This project is a clear demonstration that infrastructure works and bat conservation are not mutually exclusive. With the right planning, expert survey work, and real-time on-site management, flood protection can proceed without compromising one of New Zealand’s rarest and most vulnerable species.

Case study 2: When one tree said wait - Porangahau

  • Eleven exotic trees along the Pōrangahau River needed to be removed as part of flood protection works. A previous Step 1 acoustic survey had already confirmed that long-tailed bats were active in the project area, meaning the question was no longer “are bats present?”, but “which trees might they be roosting in, and can we fell them safely?” The client needed the remaining protocol steps completed quickly, within a tight felling window.

  • We began with a Bat Roost Potential Assessment (BRPA), assessing all 11 trees proposed for felling and identifying those with potential roost features; cavities, cracks, hollows, or loose bark that a pekapeka might use as a day roost. Trees were scored High, Moderate, or Low based on their roosting potential. Following the BRPA, we deployed acoustic detectors for pre-felling monitoring across two consecutive valid survey nights. We were on site for all felling days, using a handheld bat detector and endoscope camera to inspect each tree once felled before it was removed from site.

  • One tree had to wait. Bat activity was detected adjacent to a high-PRF tree on the first monitoring night, meaning felling of that tree was delayed until two consecutive bat-free nights were achieved. Once those conditions were met, it was felled safely. All 11 trees were eventually removed and no bats were harmed. The project also confirmed long-tailed bat activity at a second location within the project area, new information added to the national database.

  • This project illustrates exactly why the Bat Roost Protocols exist: not to stop work from happening, but to ensure that when bats are present, felling is timed to avoid harm. A one-day delay on a single tree is a small price for ensuring a Nationally Critical species isn’t killed in the process.

Case study 3: Bats and solar - Masterton Agrivoltaic Facility

  • A 143-hectare agrivoltaic (solar farm) development near Masterton required a comprehensive bat management programme as a condition of resource consent. Long-tailed bats were known to use the wider area, and the site contained dozens of mature exotic trees, poplars, pines, willows, macrocarpa, many with features that could provide bat roost sites. The client needed a complete ecological framework covering pre-construction survey, vegetation clearance management, construction controls, and five-plus years of operational monitoring.

  • This was our most comprehensive bat engagement to date. We began with a full-season pre-works acoustic bat survey, deploying 23 detectors across 23 sites (including four control sites) for three survey rounds covering December 2025, January–February 2026, and March–April 2026. This generated over 1,400 detector-nights of data, documenting long-tailed bat activity in detail across different seasons and habitat types.

    Concurrently, we carried out a detailed Bat Roost Potential Assessment across 13 discrete vegetation areas, scoring every tree proposed for clearance. We then authored a full Bat Management Plan and a Bat Monitoring Plan establishing a five-year control-impact acoustic monitoring programme. Prior to vegetation clearance we implemented Steps 4 and 5, including pre-felling acoustic monitoring and on-site supervision, with endoscope and thermal camera inspections of every removed tree.

  • All vegetation clearance was completed in compliance with the Bat Roost Protocols and the Bat Management Plan. No bats were harmed. Baseline bat activity data from three survey rounds now provides a robust foundation against which future operational impacts can be measured. The monitoring programme will continue annually for five years and feed into the DOC National Bat Database.

  • New Zealand’s renewable energy sector is growing fast, and bat management is increasingly a condition of consent for large-scale infrastructure projects. This engagement demonstrates TBCL’s capacity to deliver end-to-end bat ecology services for complex, multi-year projects, from initial survey design through to long-term monitoring frameworks built to survive regulatory scrutiny.

We’re building something bigger…

We believe protecting bats starts with understanding them. The National Bat Survey (see map), along with our independent projects, are our commitment to building a better picture of bat populations across New Zealand. We do this by creating opportunities for people to contribute, learn and take part in meaningful ecological monitoring. By combining community participation with scientific expertise, we hope to generate knowledge that supports conservation, informs decision making, and creates lasting impact for bats and the landscapes they depend on.

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