Bitterns came within six breeding males of extinction in the UK in the 1990s but have recovered through targeted wetland restoration. Their welfare depends on high-quality reed bed management.
Bittern welfare in winter is most precarious during cold spells that freeze reedbed water and cut off access to fish and amphibian prey. Individuals that cannot locate unfrozen water within their territory lose body condition rapidly and may die of starvation. Bitterns are highly cryptic and welfare problems are difficult to detect without intensive monitoring. Reedbed management that maintains open water channels through winter and provides fish refuges reduces winter mortality significantly. During breeding, disturbance of incubating females causes nest abandonment that results in egg chilling and embryo mortality. The species' recovery from near-extinction demonstrates that targeted habitat management can deliver substantial welfare and conservation improvements.