On April 23, 2021 we had our first gray whale calf predation event of the season. We witnessed our only documented gray whale calf attack/kill for this season!
We observed the last ninety minutes of the attack, ending when the killer whales drowned the calf. Another vessel first spotted them. CKWP team members Nancy Black and Bradley Vanston arrived soon afterwards, at 0913 (Pt. Sur Clipper); Alisa Schulman-Janiger, Colleen Talty , and Tomoko Shimotomai arrived at 0925 (Sea Wolf 2). There were ~10 killer whales, including the CA51s (Star’s family) and the CA140Bs (Louise’s family, with CA23A2). The attack had been underway for some time. There were at least 50 gulls and two black-footed albatross feeding on floating scraps of flesh. The calf’s lower left jaw was broken and displaced; most of its baleen was ripped out, and it was bleeding from its gums. Shortly before we arrived, a separate group of killer whales (the CA51As, Louise’s family) raced over from another location, joining the attack almost 20 minutes later - raising our killer whales count to 15 (including CA50B).
The attack involvement of individual killer whales was directly proportional to gender, age, and experience. As we have seen in previous attacks, the three reproductive females were by far the most active; each has multiple offspring, including a calf under two years old.
Head matriarch CA51 Star was involved in the majority of activity, especially during the first hour: repeatedly ramming the gray whale calf (as many as five times in just over a minute), body slamming and breaching on it and laying on it, and trying to separate it from its mom. (CA51 is at least 40 years old, and was one of our eight original key matriarchs involved in gray whale calf attacks in the early 1990s). Her eldest daughter CA51A Aurora (~28 years old) was the next most active attacker. CA140B Louise (19 years old) was the third key attacker. (CA140B's mom is CA140 Emma - another original key matriarch involved in the 1990s attacks). Young females CA51E Comet and CA51A2 Andi (both 10 years old) also assisted; they lay on top of the calf to try to drown it, and may have rammed it underwater, demonstrating predation techniques they would need as future matriarchs. Various juveniles were often close by, learning attack techniques (“Orca School”). Moms guided their youngest calves very close to the action; older whales babysat youngest calves while their moms were actively attacking. The three adult males were nearly absent during the attack.
CA51C Bumper entered the attack zone a few times; he disappeared underwater and might have rammed the gray whale calf or mom. He also visited some boats (one of his favorite activities), and babysat his youngest sibling CA51F. CA50B passed closely several times, and also disappeared underwater close to the calf. Two whales – adult male CA51B Orion and young female CA23A2 – were never seen attacking the calf. (Afterwards, we observed that they appeared to be more interested in each other than in the predation). Near the end, CA140B grabbed the calf’s pectoral flipper and tried to force it down. Multiple whales rammed it at once. At 1038, CA51A, CA51E, and adult male CA50B laid on top of the thrashing calf. CA51A repeatedly forced the calf down when it tried a few more times to take a breath; it drowned.
This gray whale mom fought valiantly to save her calf, although it had no chance of surviving with those grievous injuries to its mouth and jaw. She dove multiple times to rescue her calf, resting it on her head or back so that it could breathe while protected from some hits. She tried to block the killer whales with her pectoral flippers and flukes, and flailed out at them with her flukes. When she dove to try to save her drowning calf, the killer whales interfered; her pectoral flipper was bleeding when she resurfaced, and she might have been injured internally (greenish water visible near her ventral surface). The mom left within three minutes of her calf's last breath. The end of this calf's suffering and life marked the beginning of an unprecedented four days of feeding and socializing on a single kill - for multiple killer whale matrilines.
After the hectic morning with the gray whale calf predation event, CA51 Star shares tender cuddles with her new calf CA51F, who did an extended headstand against her body and caressed her dorsal fin and back with its peduncle and tiny fluke. These tight family bonds are forever: male Bigg's transient killer whales nearly always stay with their moms, while daughters like CA51A Aurora periodically reunite with moms after leaving with their own offspring to start new families. A very special glimpse into rarely seen intimate moments in the emotional lives of these long-lived beings.
ID by California Killer Whale Project
Summary and photos by CKWP Lead Research Biologist Alisa Schulman-Janiger.