Butyric acid (from Greek βούτυρο, meaning "butter"), also known under the systematic name butanoic acid, is a carboxylic acid with the structural formula CH₃CH₂CH₂-COOH. Salts and esters of butyric acid are known as butyrates or butanoates. Butyric acid is found in milk, especially goat, sheep and buffalo's milk, butter, Parmesan cheese, and vomit, and as a product of anaerobic fermentation (including in the colon and as body odor). It has an unpleasant smell and acrid taste, with a sweetish aftertaste (similar to ether). It can be detected by mammals with good scent detection abilities (such as dogs) at 10 ppb, whereas humans can detect it in concentrations above 10 ppm.

Butyric acid was first observed (in impure form) in 1814 by the French chemist Michel Eugène Chevreul. By 1818, he had purified it sufficiently to characterize it. The name of butyric acid comes from the Latin word for butter, butyrum (or buturum), the substance in which butyric acid was first found.

Butyric acid is a fatty acid occurring in the form of esters in animal fats. The triglyceride of butyric acid makes up 3% to 4% of butter. When butter goes rancid, butyric acid is liberated from the glyceride by hydrolysis, leading to the unpleasant odor. It is an important member of the fatty acid subgroup called short-chain fatty acids. Butyric acid is a weak acid with a pKa of 4.82, similar to acetic acid, which has pKa of 4.76. The similar strength of these acids results from their common -CH₂COOH terminal structure. Pure butyric acid is 10.9 molar.

Stephen Robert "Steve" Irwin (22 February 1962 – 4 September 2006), nicknamed "The Crocodile Hunter", was an Australian wildlife expert, television personality, and conservationist. Irwin achieved worldwide fame from the television series The Crocodile Hunter, an internationally broadcast wildlife documentary series which he co-hosted with his wife Terri. Together, the couple also owned and operated Australia Zoo, founded by Irwin's parents in Beerwah, about 80 kilometres (50 mi) north of the Queensland state capital city of Brisbane. Irwin died on 4 September 2006 after being pierced in the chest by a stingray barb while filming an underwater documentary film titled Ocean's Deadliest. The Sea Shepherd Conservation Society ship MY Steve Irwin was named in his honour.

Irwin was born on his mother's birthday to Lyn and Bob Irwin in Essendon, a suburb of Melbourne, Victoria. He moved with his parents as a child to Queensland in 1970, where he attended Landsborough State School and Caloundra State High School. Irwin described his father as a wildlife expert interested in herpetology, while his mother Lyn was a wildlife rehabilitator. After moving to Queensland, Bob and Lyn Irwin started the small Queensland Reptile and Fauna Park, where Steve grew up around crocodiles and other reptiles.

Robert William "Bob" Barker (born December 12, 1923) is a former American television game show host. He is best known for hosting CBS's The Price Is Right from 1972 to 2007, making it the longest-running daytime game show in North American television history, and for hosting Truth or Consequences from 1956 to 1975.

Born in Washington to modest circumstances, Barker enlisted in the United States Navy on the outbreak of World War II. Barker worked part-time in radio while he attended college. In 1950, Barker moved to California in order to pursue a career in broadcasting. He was given his own radio show, The Bob Barker Show, which ran for the next six years out of Burbank. Barker began his game show career in 1956, hosting Truth or Consequences. From there, he hosted various game shows as well as the Miss Universe pageants. Eventually, he hosted The Price Is Right, beginning in 1972. When his wife Dorothy Jo died, Barker became an advocate for animal rights. Since then, Barker has been a long-time supporter of animal rights, and of animal-rights activism, including groups such as the United Activists for Animal Rights and the Sea Shepherd Conservation Society. In 2007, Barker retired from hosting The Price Is Right after celebrating his 50-year career on television.