Orcas' complex world of grieving mothers, playful pods 

A grieving orca mother that made global headlines in 2018 for carrying her dead calf is doing so once again following the death of another calf. In 2018, she carried her first calf more than 1,600 kilometers (1,000 miles). On New Year's Day 2025, US officials confirmed that the orca was carrying the dead body of her new calf.

Calf mortality among orca pods is high. Only about one in five orca pregnancies result in a calf that lives to its first birthday, according to the Center for Whale Research in the state of Washington. Human activity plays a role. Most orca calves die of malnutrition — researchers say decades of overfishing have reduced food stocks. "Vessel strike-related trauma" is another leading cause of death.

Like other whales, orcas have sophisticated ways of communicating by clicks and calls. Researchers call this "whalish" and have been trying to decode the meaning of whale phonetic alphabets using artificial intelligence. Underwater noise created by shipping is known to interfere with whale communication and increase the chances of collisions.

Orcas have made headlines in recent years for attacking several vessels, particularly in the Strait of Gibraltar and along the Atlantic coast of Iberia. Until 2020, there were few incidents of this behavior. Scientists aren't sure if the behavior is aggressive, or if the attacks are playful teenage antics.

Orcas are highly social animals and form strong bonds within their pods. Experts believe that playful behavior such as breaching (jumping out of the water), spy-hopping (poking their heads out of the water to look around) and tail-slapping (smacking their tails on the water's surface) help orcas to form social bonds, especially among younger animals. 

Worldwide, there are around 55 orcas being kept by humans for breeding or performance purposes. Thirty-three were born in captivity. The practice of keeping orcas in captivity is controversial. Captured orcas live separated from their familial pod, and often have health problems. The majority have not lived past the age of 25. Wild orcas, by contrast, can live up to 90 years.

The largest orca in captivity, Tilikum, lived to the age of 35. Tilikum featured in CNN Film's 2013 documentary "Blackfish," which claims that orcas in captivity suffer psychological damage and become unnaturally aggressive. Four humans have been killed by captive orcas, and Tilikum was involved in three of those deaths. Tilikum died in 2017.