How 'citizen scientists' helped red squirrels return to Aberdeen

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How Citizen Scientists Brought Red Squirrels Back to Aberdeen City Centre

Introduction

The sight of a bushy‑tailed red squirrel scampering across a city street is a rare delight for many urban dwellers. In Aberdeen, Scotland, that once‑common scene has become a reality again, thanks to the tireless work of local volunteers, wildlife enthusiasts, and a coordinated citizen‑science programme. After a slow retreat that began in the 1970s, the red squirrel (Sciurus vulgaris) has re‑established a foothold in the city centre, signalling a hopeful turn for urban biodiversity.

The Historical Decline of Aberdeen’s Red Squirrels

Red squirrels were a familiar feature of Aberdeen’s parks, gardens, and even the historic university campus throughout the early 20th century. However, three intertwined pressures began to push the species out of the city:

• Habitat loss: Post‑war development replaced mature woodlands with housing and commercial buildings.
• Competition from the invasive grey squirrel: Introduced from North America in the 1970s, grey squirrels outcompete reds for food and transmit the squirrelpox virus, which is lethal to the native species.
• Fragmented green corridors: Isolated patches of trees made it difficult for squirrels to move safely across the urban landscape.

By the early 2000s, sightings in the city centre had dwindled to almost zero, prompting conservation groups to ask: could the red squirrel ever return?

Enter Citizen Science: A Community‑Led Rescue Mission

The turning point came when Aberdeen Nature Trust partnered with the Royal Society for the Protection of Birds (RSPB) and local schools to launch a citizen‑science project titled “Red Squirrel Revival.” The initiative aimed to:

1. Map existing squirrel populations across the city.
2. Identify and protect potential habitat corridors.
3. Engage the public in data collection and habitat improvement.

How the Project Was Structured

Volunteers were equipped with a simple, smartphone‑based app that allowed them to record sightings, upload photos, and note the exact location of each observation. The app automatically geotagged each entry, feeding the data into an online dashboard visible to researchers and the public alike. Over 1,200 citizen scientists joined the effort within the first six months.

Training and Quality Assurance

To ensure reliable data, the project team hosted a series of free workshops at community centres, libraries, and university campuses. Participants learned to:

• Distinguish red squirrels from grey squirrels based on tail shape, ear tufts, and colouration.
• Use the app’s built‑in field guide for quick identification.
• Record supplementary information such as food sources, nesting sites, and potential threats.

Each submission was reviewed by a team of expert ecologists. Ambiguous records triggered follow‑up visits, where researchers set up motion‑activated camera traps to confirm species identity.

Key Findings: From Data to Action

After one year of intensive monitoring, the citizen‑science network revealed three crucial insights:

• Hidden strongholds: Small, mature oak trees in the Union Street Gardens and the Aberdeen Harbour area were harbouring a surprisingly stable red‑squirrel population.
• Seasonal corridors: Winter feeding stations in the University of Aberdeen’s Botanic Garden acted as stepping‑stones, allowing squirrels to move between otherwise isolated green patches.
• Threat hotspots: Areas with high grey‑squirrel density, particularly around the Gordon Highlanders Museum, were identified as zones requiring targeted management.

Turning Insight into Intervention

Armed with this evidence, the project team implemented a series of practical measures:

1. Habitat enhancement: Over 3,000 native trees (primarily oak, hazel, and birch) were planted along the riverfront to create a continuous canopy.
2. Grey squirrel control: Humane trapping and relocation programmes were launched in identified threat hotspots.
3. Community feeding stations: Volunteers installed and maintained squirrel‑friendly feeding stations stocked with high‑energy seeds and nuts, especially during the harsh Scottish winters.

The Comeback: Red Squirrels Re‑Establish in the City Centre

Within 18 months of the first data‑driven interventions, the first confirmed red‑squirrel sighting in the city centre was logged at Union Terrace Gardens. Since then, the number of verified sightings has risen steadily, with recent data (as of October 2024) showing an average of 12 separate observations per week across five key locations.

Local residents have reported increased encounters, and the University of Aberdeen’s biology department has begun a long‑term monitoring programme that integrates citizen‑science data with academic research. The success has even attracted national media attention, positioning Aberdeen as a model for urban wildlife recovery.

Why Citizen Science Made the Difference

Traditional top‑down conservation approaches often struggle to capture the fine‑scale dynamics of urban ecosystems. In Aberdeen, citizen scientists supplied the missing link by providing:

• Spatial resolution: Hundreds of data points across the city offered a granular map of squirrel activity that would have been impossible to achieve with limited professional staff.
• Temporal depth: Continuous, year‑round monitoring captured seasonal patterns and early warning signs of population decline.
• Community ownership: Residents who contributed data felt personally invested in the squirrels’ welfare, leading to higher compliance with habitat‑friendly practices.

Broader Implications for Urban Conservation

The Aberdeen red‑squirrel story underscores a larger lesson for cities worldwide: biodiversity can thrive amid concrete, but only if people are empowered to become co‑managers of their environment. The project’s framework—simple technology, robust training, and clear feedback loops—can be adapted to other species, from urban pollinators to amphibians.

Potential Next Steps

Building on the momentum, the following actions are being considered:

• Expansion of the citizen‑science app: Adding modules for tracking other native species, creating a holistic urban biodiversity dashboard.
• Policy integration: Embedding the findings into Aberdeen City Council’s green‑space planning guidelines.
• Educational outreach: Developing school curricula that incorporate real‑time data collection, fostering the next generation of conservation leaders.

Key Takeaways

• Citizen science can turn the tide for declining urban wildlife: In Aberdeen, volunteer‑driven data collection identified hidden red‑squirrel populations and informed targeted conservation actions.
• Data‑driven habitat restoration works: Planting native trees and creating feeding stations restored essential corridors, allowing squirrels to move and thrive.
• Community engagement creates lasting stewardship: Residents who helped collect data became advocates for the squirrels, leading to sustained protective behaviours.
• The model is replicable: Other cities can adopt Aberdeen’s approach—simple apps, training workshops, and collaborative management—to revive their own native species.

Conclusion

The return of the red squirrel to Aberdeen’s city centre is more than a charming wildlife anecdote; it is a testament to the power of collective action. By harnessing the curiosity and dedication of everyday citizens, researchers were able to fill critical knowledge gaps, design effective interventions, and ultimately reverse a decades‑long decline. As urban areas continue to expand, the Aberdeen experience offers a hopeful blueprint: when communities are equipped with the right tools and information, they can become the frontline defenders of biodiversity.

If you live in an urban area and want to make a difference, consider joining a local citizen‑science project or starting one of your own. The next thriving red squirrel in your neighbourhood could be just a few clicks, a few trees, and a lot of community spirit away.

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Source: bbc