In 1969 cases of malignant lymphoma were reported in a single colony of white - handedgibbons in a US military research facility in Bangkok, Thailand and were at the time attributed to an unknown infectious agent.
Videos of two captive white - handedgibbons (Hylobates lar) leaping from one branch of a jungle gym to another reveal that the apes break the record for work per mass performed in a single movement by any other species to date.