October 2025 Progress Update to BHPS

Project Objectives and Approach

The Passive Hedgehog Monitoring Project aims to develop affordable, reliable monitoring stations to record hedgehog movements in gardens and community spaces. These monitoring stations are able to record known individuals using microchips, and record behaviours using camera trapping. By using off-the-shelf components and supplementing them with in-house 3D-printed and laser-cut parts, we are able to keep costs low, ensure supply chain reliability, and make the system easy to maintain. The approach combines practical innovation with long-term sustainability, allowing the project to remain adaptable over time, and become self-funded.

Here we present the key achievements and successes that we have reached so far. This includes the results from pilot studies using the technology that we have developed. Additionally, we discuss some of the challenges that have impacted the timeline of our plans, and what we aim to complete in the next three months. 

Photo 1: View towards exit, the black ramp is a pressure plate to wake up the unit.

Key Achievements / Successes

We have successfully designed a microchip monitoring station with data recording suitable for scientific research, alongside secure and standardised camera trapping for observing hedgehog behaviour. Key details of these tracking stations are highlighted below. 

Photo 2: Monitoring station without the lid.

Core System Reliability

We have successfully demonstrated accurate and consistent microchip reading, proving the stations work reliably in real garden environments.

Expanding Monitoring Capabilities

We designed a 3D-printed camera mount that securely holds low-cost Amazon Blink cameras. 24 units were purchased on discount, and standardised mounting ensures consistent video across sites. This allows us to capture visits from unchipped hedgehogs, broadening the data collected. An electronics shield was also integrated to provide a clear upgrade path for future features.

Photo 3: Monitoring station with customisable entrance.

Rapid Design Progress

Over 14 design versions were completed in six months, covering electronics, 3D-printed parts, and laser-cut housings. This rapid cycle of iteration has made the system more robust, easier to deploy, and more suitable for real-world conditions.

Photo 4: Multiple iterations of design and prototypes.

Modularity and Customisation

Stations were designed for easy maintenance: components can be swapped with only a few screws, and more expensive electronics are removable to allow easy reuse on future design iterations. A 3D-printed entrance plate improves aesthetics and allows for sponsorship or naming opportunities, supporting future fundraising.

Photo 5: Custom camera mount is easily removed.

Data Handling and Power Efficiency

We introduced on-board clock and memory storage so data can be logged locally and uploaded in batches, reducing power use. A reliable daily reporting system now provides consistent hedgehog sighting updates.

Photo 6: Camera field of view tested within 3D model.

System Reliability & Maintenance Improvements

We added a system heartbeat to detect failures sooner, alongside hourly battery voltage monitoring. To save power, heartbeats are reduced overnight. All data is stored locally and transmitted once connectivity is restored, minimising data loss.

Photo 7: Antenna and wire assembly during 3D printing.

Results So Far

We have conducted pilot studies to illustrate the success and potential of the monitoring stations. The first year of testing has produced a substantial dataset that already reveals clear patterns in hedgehog activity. From October 2024 to October 2025, the monitoring station at Prickly Pigs recorded:

• 2,536 visits (after applying the visit definition: multiple detections within 20 minutes counted as one visit).

• 26 unique hedgehogs identified by microchip, alongside a few test chips and even a feline interloper.

• The most frequent visitor was Walnut, with 532 visits across the year.

• The busiest night was 11 May 2025, when 30 visits from 7 hedgehogs were recorded.

• Typical visits lasted from just a few minutes to over 30 minutes, reflecting both quick pass-throughs and longer feeding stops.

Photo 8: Finished antenna module with wires installed (viewed from rear).

Seasonal Patterns

Activity followed a clear seasonal trend. Hedgehog visits increased steadily through spring, peaked in late spring and early summer, and declined into the autumn — a pattern consistent with natural behaviour as hedgehogs prepare for hibernation (Figure 1).

Figure 1: total monthly visits compared with the number of offline days (e.g. during upgrades battery issues, or summer pause).This highlights where lower visit counts may be due to system downtime rather than absence of hedgehogs.

Individual Presence

The number of unique hedgehogs detected each month shows a similar seasonal pattern, with the highest diversity of visitors in spring and summer. Overlaying this with offline days again helps interpret gaps in detections (Figure 2).

 Figure 2: number of unique hedgehog visits compared with the number of offline days (e.g. during upgrades, battery issues, or summer pause). This highlights where lower visit counts may be due to system downtime rather than absence of hedgehogs.

System Reliability

Downtime was most noticeable in February 2025 (19 days) and June 2025 (15 days), often linked to testing or power supply challenges. Even so, the system demonstrated the ability to generate consistent nightly reports when online, proving the concept is robust and scalable.

 Photo 9: Electronics were tested on Veroboard prior to commercial manufacturing.

Survey Timing and Reporting Timeline

As we move into the winter months, we plan to slow down the pace of design iterations and place greater emphasis on longer deployments. The focus will be on testing the longevity and resilience of the stations. We expect to deploy five units over winter, and thanks to supporter gardens and release sites, hedgehog visits are likely to continue. The 12-month survey period remains unchanged, with interim updates provided throughout. The final report is now scheduled for release in the first or second quarter of 2027.

 Photo 10: Electronic design completed using Ki-Cad software allowing for fast revisions.

Timeline adjustment

The project is currently three months behind its original volume deployment, but ahead on technical capability. As we developed the design, the speed of iterations would require remaking dozens of deployed units. The delay reflects deliberate choice to ensure quality and robustness rather than setbacks and increased cost.

Photo 11: Circuit boards commercially manufactured and assembled by the project team. Design facilitates reusing as many components as possible between revisions.

Two main factors contributed:

• Extensive prototyping – We initially expected to need only one or two prototypes before deployment, but instead completed 14 design iterations over six months. Each revision improved reliability and usability, though it meant fewer units were deployed simultaneously.

• Strategic summer pause – During the summer holidays we made a conscious decision to slow deployment so that team members could rest and recharge allowing us to return with renewed energy and clearer focus.

Photo 12: The RFID reader was susceptible to interference. Smoothing components were added into the next version.

Challenges Faced

Battery Lifespan

Our toughest challenge  has been battery lifespan. Initially, the priority was to ensure reliable hedgehog microchip reading, with power efficiency a secondary concern. Once that reliability was proven, focus shifted to power optimisation. We redesigned the electronics around a more efficient micro-controller and trialled infrared sensors. However, early designs still drew too much power and required heavy car batteries.

Photo 13: Testing outside.

As a temporary solution, we introduced a pressure plate activated by hedgehog weight, which uses no standby power. This allowed deployments to continue using much smaller batteries. while we work toward a smarter, more robust, low-energy trigger system for the future.

Photo 14: Initial sketches of the entrance design incorporating name plate to allow customisation.

Technical Reliability in the Field

Another challenge is protecting sensitive electronics from moisture (and slugs). Even small amounts of damp can shorten or destroy components. We are using IP-rated housings and testing moisture-absorbing sachets to help keep units dry. The long-term effects of exposure across seasons remain an important unknown.

Photo 15: Artwork digitised with colour wash prior to importing for 3d modeling.

Balancing Prototyping with Deployment

Rapid iteration has been key to improving the system, but each design cycle reduces the number of units available for immediate deployment. Although this has meant a slower pace in getting multiple units into the field, we do not see this as affecting the overall monitoring duration. The project’s 12-month survey period remains intact, and the design refinements carried out now will reduce issues later and improve the quality of the long-term data collected.

Photo 16: Mushroom entrance is not just decorative, it acts as a locking mechanism securing the unit & covering the sharp edges of the cut plastic box. Facilitates quick cleaning and replacement.

Three-Month Look Ahead

In the next quarter, the focus will be on stabilising deployments and addressing key technical challenges. Goals include: finalising a low-power trigger system; testing durability through winter; validating detections against camera footage with the help of citizen science volunteers, trialling solar recharging. Additionally, as part of our collaboration with the University of Leeds, we have developed a network of hedgehog rescues and researchers to establish UK-wide monitoring of micro-chipped hedgehogs. In the next few months we will be planning the development of GIS mapping interface for hedgehog sightings, planning research into the social psychology of hedgehog conservation, and piloting the use of stations as hedgehog highway monitors to identify barriers in the landscape.

Photo 17: Early prototype destroyed by "Danger slugs".

Wish List and Long-Term Goals

Looking further ahead, we aim to create fully solar-powered stations, build a nationwide monitoring network, expand volunteer training and assembly, map barrier crossings in more detail, and establish a public engagement platform to display findings. Additional goals include introducing sponsorship schemes to support funding and sharing research data through formal partnerships.

Photo 18: Slug proof revision.

Finance and Sustainability

The project is funded primarily by the British Hedgehog Preservation Society (BHPS), with Prickly Pigs contributing both money and volunteer time. We remain within budget and have achieved savings through bulk purchasing, enabling us to procure higher quantities of spare parts and improve resilience. We continue to seek contributions and donations to extend funding further. Our financial model combines supporter sponsorships and grants or partnerships, ensuring long-term sustainability. 

Photo 19: View captured by internal hog cam.

Help fund our project via our Matched Funding scheme: Prickly Pigs Hedgehog Rescue - Building Fund - a Community crowdfunding project in Otley by Andrew Cook

You can pay for products in our online show via our match funding scheme, just work out what you want in the shop and total it up, then make a donation on the match funding page letting us know you want to buy from the shop, we'll get in touch to sort out the order. We get paid much more this way.