Millions of migratory birds pass through geographical bottlenecks during migration, where concentrated populations face hunting, trapping, and habitat degradation welfare threats.
Migratory birds at flyway bottlenecks experience a perfect storm of welfare threats concentrated in time and space. After the physiological demands of long-distance flight - burning fat reserves, sometimes crossing large water bodies or deserts without feeding - birds arriving at bottlenecks are in a vulnerable state of energy depletion. Illegal trapping at these locations exploits their concentrated vulnerability: birds depleted by migration cannot flee as effectively as resident birds, and their concentration makes large-scale capture economically viable for poachers. Lime sticks - branches coated with sticky adhesive - trap birds that land exhausted on vegetation, causing wing and feather damage as they struggle. Mist nets, set in migration corridors, entangle birds that then suffer from exhaustion, injury, and hypothermia before being killed or escaping with injuries. The scale is staggering: 25 million illegal kills annually means individual welfare harm is multiplied across an almost incomprehensible number of animals. Conservation campaigns that reduce illegal killing at bottlenecks are simultaneously welfare interventions of enormous scale.