The secretary bird (Sagittarius serpentarius) is named because of its quill-like crests on the back of its head that resemble 18th century clerks with pens tucked into their wigs. Dangerous prey, such as snakes, are first stamped on to stun them and then pecked behind their neck to kill them. The secretary bird also stamps on the ground with its large stout-toed feet to flush prey out of hiding. It is a very large, mostly terrestrial bird of prey – it can measure 1.3 – 1.4 metres (around 4.5 feet) in height, weigh 3.3 kilograms (7.3 pounds) and have a wingspan of over 2 metres (6.6 feet). Endemic to Africa, it is usually found in the open grasslands and savannah of the sub-Saharan region. It flies well but needs a long take-off run prior to leaving the ground. Secretary birds mate for life and although out of breeding season they can be solitary, the other half of a pair is usually not far away. The Secretary Bird is the prominent emblem of Sudan and South Africa and appears on both nations coat of arms.