Observation of a Predation of a Humpback Whale Calf by two Killer Whales

Observation of a Predation of a Humpback Whale Calf by two Killer Whales (Orcinus Orca)

We observed two male Killer Whales (Orcinus orca) kill and partially ingest 6-7 meter Humpback Whale (Megaptera novaeangliae) near Roca Pardita which is one of the  Revillagigedos Islands—more commonly known as the Socorro Islands, Mexico

(18° 59.325 N, 112° 04.519 W)

The following is based on personal observations, field notes, photographs and video documentation of the event.

Caution Graphic Content of Wild Animal Behavior:

At 8:00 on 29 January, 2015 I (JM) spotted a female Humpback, her male calf and a male Humpback Whale escort near Roca Pardita.  The Whales had been observed at this location for about 24 hours prior during daylight hours.  During the time of observation by SCUBA and free-diving the whales relaxed mid-water with the calf surfacing every few minutes, we did not observe the calf actively feeding but we did observe the calf in a position that one would assume he was trying to feed at one time. during these observation dives the Mother Humpback Whale, Calf and Male Humpback Escort appeared to be heathy.  During these SCUBA dives and freedives the Mother would freely move about the divers in close proximity.

At 9:16 after completing an hour long SCUBA dive around the whales, we had returned to the inflatable boats to drop off our tanks.  Once on board we were relocating the vessel to enter the water to free dive with the Humpbacks as we had the prior day.  At 9:24 (est) just seconds prior to entering the water I (JM) observed a normal blow from the female humpback and then a breach by a Male Orca on the humpback calf. Upon this I additionally observed a gush of blood from the calf.

The Female immediately began aggressive behaviors which included loud and forceful exhalations (trumpeting loudly) and she spun at the surface slashing and slapping of her flukes and flippers.

The Male Escort also arrived within a second and lunged breached upon one of the Orca and continued to slap with its flukes and flippers vigorously trying to defend the calf.  The male escort also continued with loud and forceful exhalations.

The Escort and female to continued roll onto the Killer Whales back side first with continued slashing, slapping of pectoral fins and flukes. This extreme activity of the whales slashing, slapping fins lasted for less than three minutes.