Felidae carnivores, meaning they are dependent on nutrients in animal flesh for survival, and because of the large proportion of meat in their diet they are sometimes referred to as hypercarnivores. Of the 13 terrestrial families in the order Carnivora, they are the strictest carnivores. The Felidae comprises two subfamilies, the Pantherinae and the Felinae. The former includes the "Panthera" species tiger, lion, jaguar, leopard, snow leopard, and "Neofelis" species clouded leopard and Sunda clouded leopard. All the non-pantherine cats are part of the Felinae, which includes several genera and the majority of cat species. The first cats emerged during the
World Day for Laboratory Animals groups opposed to the use of animals in research. In April 2010 protesters marched through central London calling for an end to the use of animals in research. A similar march took place in Birmingham in 2012. and Nottingham in 2014. World Day and World Week For Animals In Laboratories have also attracted attention from scientific groups defending the use of animals in research. On 22 April 2009 members of UCLA Pro-Test held a rally in support of biomedical research on animals, and to condemn the violence and harassment directed at faculty member Prof. David Jentsch by animal activists. NAVS