Tilikum (c. December 1981[1] – 6 January 2017), nicknamed Tilly,[2] was a captive male orca who spent most of his life at SeaWorld Orlando in Florida.

[citation needed] Tilikum was heavily featured in CNN Films' 2013 documentary Blackfish, which claims that orcas in captivity suffer psychological damage and become unnaturally aggressive.

[10] His name, in the Chinook Jargon of the Pacific Northwest, means "friends, relations, tribe, nation, common people".

[3] After almost a year in a tank at the Hafnarfjördur Marine Zoo, he was transferred to Sealand of the Pacific, in Oak Bay, a suburb of the city of Victoria on Vancouver Island, Canada.

As both orcas were pregnant, Haida II and Nootka IV behaved aggressively towards Tilikum, including forcing him into a smaller medical pool where trainers kept him for protection.

[19] According to the coroner's report, rescue attempts were thwarted by the whales, who refused to let Byrne go even after she was believed to have fallen unconscious in the water.

[20][21] Shortly after the accident, Sealand management made the decision to sell all of its orcas to SeaWorld and, eventually, to close the park entirely.

On January 3, 1992, SeaWorld applied to the National Marine Fisheries Service for a temporary emergency permit to bring Tilikum to the United States due to concerns for his health.

He had been the subject of systematic aggression from Nootka and Haida after the latter gave birth to a calf, Kyuquot, on December 24, 1991, and was confined in a small medical pool that was only slightly larger than he was.

[citation needed] Steve Huxter, head of animal training at Sealand at the time, said, "They never had a plaything in the pool that was so interactive.

"[24] No official motive of the three whales has ever been established, as the case was over twenty years old by the time it resurfaced in relation to the death of Dawn Brancheau.

Dukes was generally regarded by the media as a trespasser and nuisance rather than a direct victim of Tilikum, although this perception has been challenged with the release of the documentary Blackfish.

[27] According to the Orange County Sheriff's Office (OCSO) report, a 911 call was received from SeaWorld at 7:25 a.m., at almost the exact time that Dukes's body was spotted.

Former marine mammal trainer Ric O'Barry argued that Dukes was probably not near Tilikum's tank with any form of malicious intent, but instead that the nature-loving man was "fascinated" by the whale and wanted to visit it.

[37] Brancheau's death resulted in a contentious legal case over the safety of working with orcas and the ethics of keeping live whales and other marine mammals in captivity.

High-pressure water hoses were used to massage him, rather than hands, and removable guardrails were used on the platforms, as OSHA restricted close contact between orcas and trainers, and reinforced workplace safety precautions after Brancheau's death.

Among Tilikum's other offspring are: Nyar (1993–1996), Unna (1996–2015), Sumar (1998–2010), Tuar (1999), Tekoa (2000), Nakai (2001–2022), Kohana (2002–2022), Ikaika (2002), Skyla (2004–2021), Malia (2007), Sakari (2010) and Makaio (2010).

In the letter, Lee refers to Tilikum as SeaWorld's "Chief sperm bank" and asserts that the relevant process constitutes continued human contact.

[51] The film and a subsequent online petition led to several popular musical groups cancelling performances at SeaWorld and Busch Gardens' "Bands, Brew & BBQ" event in 2014.