High-resolution thermal drone surveys conducted in February 2024 and March 2025 covered more than 240 km² and detected a minimum of 4,765 deer. The dominant species recorded were Chinese water deer, red deer, muntjac, and roe deer, with densities in some areas exceeding 100 deer per km².

The ecological impacts are extensive. Peat surfaces and vegetation are being degraded through track formation, wallowing, and selective browsing. This damage is hindering both natural habitat processes and active conservation management. Red deer have been observed causing erosion on flood embankments, reducing water control capacity and allowing poor-quality saline water to enter sensitive sites. Chinese water deer are browsing rare and vulnerable species, including milk parsley and fen orchid, while trampling is altering habitat structure and compromising access for management operations.

GIS mapping has demonstrated the scale of change: in 2020, deer trackways were shown to have destroyed approximately 11% of fen habitat, with deer pressure increasing year on year. Five years on, populations continue to rise and associated impacts are worsening. These spatial insights are informing targeted interventions—such as coordinated landscape-scale management through deer management groups and improved venison supply chains—to stabilise deer population growth, reduce damage to priority habitats, and support long-term ecological recovery.

For more information contact Andrea Kelly: andrea.kelly@broads-authority.gov.uk or visit the Broads Peat Partnership website.