Red squirrel (Sciurus vulgaris) populations have steadily declined in the UK due to habitat loss and, over the last 150 years, as a result of competition from the invasive American grey squirrel (Sciurus carolinensis). The estimated red squirrel population stands at approximately 140,000 individuals, with as few as 1,000 to 1,500 remaining in the priority conservation areas of Wales (Anglesey, Clocaenog and Mid Wales). In the 1990s, Clocaenog Forest in North Wales had a red squirrel density comparable to other upland coniferous forests in the UK. However, recent monitoring indicates a significant decline over the past two decades. This decline coincides with the establishment of grey squirrels in the 1980s.

The study aimed to 1) evaluate the effectiveness of camera traps in detecting red squirrels at low densities, 2) investigate their occupancy and habitat preferences across Clocaenog Forest, 3) identify challenges in monitoring low-density red squirrel populations, and 4) provide recommendations for a reliable, cost-effective monitoring strategy suitable for volunteer implementation. GIS data were used to delineate forest management units categorised by age of the trees and species composition. A stratified random sampling strategy selected 60 camera locations across conifer stands in three age categories (< 20 years, 20-40 years and 40+ years). Twenty cameras were deployed for 10 days during three independent surveys (November 2023 – January 2024). Each site was ground-baited with sunflower seeds and hazelnuts for seven days before camera activation.

The initial survey, totalling 590 camera days, did not detect any red squirrels but recorded grey squirrels and pine marten (Martes martes) at several sites. A secondary targeted survey of 200 camera-days in a favoured habitat type (40+ years old coniferous stands) detected red and grey squirrels at two sites each. Our findings indicate a significantly low population density of red squirrels within the forest, with the species likely absent from many areas.

The methodology used here proved effective in other forested regions of North Wales, suggesting that the lack of detections in Clocaenog reflects genuinely low red squirrel numbers rather than flaws in the approach. Research is needed to understand what is limiting red squirrel expansion. Potential drivers include habitat structure, tree species composition, coning cycle patterns and the presence of grey squirrels, which could be further exacerbated by localised predation pressure, road traffic mortality and poor weather conditions. Suggested management actions may include intensified grey squirrel control, reinforcement of red squirrel populations and changes in forest management practices. A consistent monitoring scheme, combining volunteer and professional efforts, is essential for tracking the status of the red squirrel population and determining the efficacy of these conservation measures.