Hazel dormice are monitored across the UK through a network of nest boxes checked monthly by trained volunteers. The National Dormouse Monitoring Programme provides population data while the boxes themselves provide critical additional nesting habitat.
Dormice in nest boxes are handled briefly during monthly checks, causing acute but short-lived stress. Licensing requirements ensure that pregnant females and newly-born litters are disturbed minimally. The welfare cost of monitoring (brief handling stress) is outweighed by the conservation benefit of population data that guides habitat management. Nest boxes themselves provide additional secure hibernation and breeding sites that directly improve individual dormouse welfare in fragmented habitats.