Annual Weigh-in At London Zoo

England Europe Great Britain London London Zoo Regent's Park UK United Kingdom ZSL Zoo Zoological Society of London animal animal welfare animals annual captivity measurement measuring ring-tail lemur weigh in weigh-in weighing Ring-tail lemurs weigh-in ZSL London Zoo annual event animal health vital statistics London United Kingdom August 19 2025 monitoring well-being keepers scale photocall record animal care zoological society conservation wildlife lemur animal welfare zoology health check animal monitoring species animal management data collection animal tracking zoo event animal measurement weight recording lemur care zoo management.