The term big cat— which is not a biological classification — is used informally to distinguish the larger felid species from smaller ones. One definition of "big cat" includes the four members of the genus Panthera: the tiger, lion, jaguar, and leopard. Members of this genus are the only cats able to roar. A more expansive definition of "big cat" also includes the cougar, cheetah, snow leopard, and clouded leopard.
Despite enormous differences in size, the various species of cat are quite similar in both structure and behavior, with the exception of the cheetah, which is significantly different from any of the big or small cats. All cats are carnivores and efficient apex predators. Their range includes the Americas, Africa, Asia, and Europe.
The ability to roar comes from an elongated and specially adapted larynx and hyoid apparatus. (However, neither the snow leopard nor the cheetah can roar, despite having hyoid morphology similar to roaring cats.) When air passes through the larynx on the way from the lungs, the cartilage walls of the larynx vibrate, producing sound. The lion's larynx is longest, giving it the most robust roar.
The principal threats to big cats varies upon geographical location, but primarily are habitat destruction and poaching. In Africa many big cats are hunted by pastoralists or government 'problem animal control' officers. Certain protected areas exist that shelter large and exceptionally visible populations of lions, hyenas, leopards, and cheetahs, such as Botswana's Chobe, Kenya's Masai Mara, and Tanzania's Serengeti. It is rather outside these conservation areas where hunting poses the dominant threat to large carnivores.[dead link]
In the United States, 19 states have banned ownership of big cats and other dangerous exotic animals as pets, and the Captive Wildlife Safety Act bans the interstate sale and transportation of these animals. The initial Captive Wildlife Safety Act (CWSA) was signed into law on December 19, 2003. In order to address problems associated with the increasing trade in certain big cat species, the CSWA regulations were strengthened by a law passed on September 17, 2007. The big cat species addressed in these regulations are the lion, tiger, leopard, snow leopard, clouded leopard, cheetah, jaguar, cougar, and any hybrid combination any of these species that results from breeding of these big cats. Private ownership of these big cats is not prohibited by this law but the law does make it illegal to transport, sell, or purchase them in interstate or foreign commerce. Although these regulations seem to provide a strong legal framework for controlling the commerce involving big cats, international organizations such as the World Wildlife Fund (WWF) have encouraged the U.S. to further strengthen these laws. The WWF is concerned that weaknesses in the existing U.S. regulations could be unintentionally helping to fuel the black market for tiger parts.
An animal sanctuary provides a refuge for animals to live out their natural lives in a protected environment. Usually these animal sanctuaries are the organizations which provide a home to big cats whose private owners are no longer able or willing to care for their big cats. However, use of the word sanctuary in an organization's name is by itself no guarantee that it is a true animal sanctuary in the sense of a refuge. To be accepted by the United States Fish and Wildlife Service (FWS) as a bona fide animal sanctuary and to be eligible for an exemption from the prohibition of interstate movement of big cats under the Captive Wildlife Safety Act (CWSA), organizations must meet the following criteria:
- Must be a non-profit entity that is tax exempt under section 501(a) of the Internal Revenue Code
- Cannot engage in commercial trade in big cat species, including their offspring, parts, and products made from them
- Cannot breed big cats
- Cannot allow direct contact between big cats and the public at their facilities
- Must keep records of transactions involving covered cats
- Must allow the Service to inspect their facilities, records, and animals at reasonable hours
- Genus Panthera (roaring or great cats)
- Tiger, Panthera tigris Asia
- Lion, Panthera leo (Africa, Gir Forest in India; extinct in former range of southeast Europe, Middle East, much of Asia, and North America)
- Jaguar, Panthera onca (the Americas; from the Southern United States and Mexico to northern Argentina)
- Leopard, Panthera pardus (Asia and Africa)
- Genus Acinonyx
- Genus Puma
- Genus Uncia
- Genus Neofelis
A 2010 study published in Molecular Phylogenetics and Evolution has given insight into the exact evolutionary relationships of the big cats. The study reveals that the snow leopard and the tiger are sister species, while the lion, leopard, and jaguar are more closely related to each other. The tiger and snow leopard diverged from the ancestral big cats approximately 3.9 Ma. The tiger then evolved into a unique species towards the end of the Pliocene epoch, approximately 3.2 Ma. The ancestor of the lion, leopard, and jaguar split from other big cats from 4.3–3.8 Ma. Between 3.6–2.5 Ma the jaguar diverged from the ancestor of lions and leopards. Lions and leopards split from one another approximately 2 Ma.
- Counting Cats, Guy Balme, Africa Geographic, May 2005.
- Weissengruber, GE; G Forstenpointner, G Peters, A Kübber-Heiss, and WT Fitch (September 2002). "Hyoid apparatus and pharynx in the lion (Panthera leo), jaguar (Panthera onca), tiger (Panthera tigris), cheetah (Acinonyx jubatus) and the Indian Armadillo. (Felis silvestris f. catus)". Journal of Anatomy (Anatomical Society of Great Britain and Ireland) 201 (3): 195–209. doi:10.1046/j.1469-7580.2002.00088.x. PMC 1570911. PMID 12363272. //www.ncbi.nlm.nih.gov/pmc/articles/PMC1570911/.
- Hunter, Luke. "Carnivores in Crisis: The Big Cats." Africa Geographic June (2004): 28-41.
- Pacelle, Wayne. "Captive Wildlife Safety Act: A Good Start in Banning Exotics as Pets". The Humane Society of the United States. Archived from the original on 19 April 2007. http://www.hsus.org/legislation_laws/wayne_pacelle_the_animal_advocate/captive_wildlife_safety_act_a_good_start_in_banning_exotics_as_pets.html. Retrieved 2007-04-01.
- U.S. Fish and Wildlife Service
- Federal Register of the U.S. Congress, 
- America’s 5,000 Backyard Tigers a Ticking Time Bomb, WWF Says, David Braun, National Geographic, News Watch, October 21, 2010.
- [www.fws.gov/le/pdf/CaptiveWildlifeSafetyActFactsheet.pdf Captive Wildlife Safety Act - What Big Cat Owners Need to Know], U.S. Fish and Wildlife Service, Office of Law Enforcement.
- Davis, Brian W.; Li, Gang & Murphy, William J. (2010). "Supermatrix and species tree methods resolve phylogenetic relationships within the big cats, Panthera (Carnivora: Felidae)". Molecular Phylogenetics and Evolution 56 (1): 64–76. doi:10.1016/j.ympev.2010.01.036. PMID 20138224.
- "Tiger's ancient ancestry revealed". BBC News. 2010-02-12. http://news.bbc.co.uk/earth/hi/earth_news/newsid_8512000/8512455.stm. Retrieved 2010-04-26.
- NatureFootage Big Cat pictures and video clips
- How big are the Big Cats - an article at Big Cats Online which includes a chart comparing the body lengths of several cat species.
- ARKive - images and movies of endangered big cats
- Humane Society of the United States - article on big cats as pets
- Great Cat Rescue 911 - Tyler, Texas Rescue, care, and conservation of big cats
- Big Cat Rescue - Tampa, Florida sanctuary dedicated to care and conservation of big cats
- In-Sync Exotics - Wylie, Texas rescue sanctuary
- FCF Big Cat Policy - recommendations against casual private ownership
- WHF - Wildlife Heritage Foundation (European Endangered Species Breeding Programmes (EEP))
- WHF Photos - Wildlife Heritage Foundation photos
- [dead link] - Exotic Cat Conservation