During their migration north along the west coast of North America, Gray whale mothers and calves face several dangers. In Monterey Bay they make the choice between a longer, safer near-shore route, or a faster route over a deep water canyon. But transient killer whales only hunt in deep water...

BBC filming report for Planet Earth Live

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For those you who want to know every last detail, here's the BBC filming report:


06:25 Left the marina on Monterey Bay Whale Watch (MBWW) boat, the Point Sur Clipper.

There were reports of a gray whale carcass floating in the bay, which the team were planning to visit, if there was no other whale activity.

08:43 – 08:56 Sighting of 1-2 minke whales. These are very elusive; we did not film.

09:19 - 12:00 Two days of strong winds had stirred up dense concentrations of krill, making great conditions for humpback whales. 

The crew were able to film several groups of humpbacks feeding.

The researchers spotted approximately 60 humpbacks; there could have been around 100 in the Bay.

12:05 Nancy received a call from the sister ship, the Sea Wolf II, to say that at least 7 killer whales were attacking a gray whale cow/calf about half an hour from our position. We turned the boat around and headed to the spot. The Sea Wolf II watched the attack for 30 minutes before we arrived.

12:35 When we arrived the attack was reaching its conclusion, with 9 killer whales participating. We filmed the calf surfacing a couple of times, and killer whales jumping on top of it; one humpback whale dove in this same location.

12:38 The gray whale calf disappeared underwater; we did not see it again. The mother gray whale milled around for about 7 minutes, making a few dives in the vicinity of her missing calf. A few killer whales briefly escorted her toward our boat.

12:45 The gray whale mum escaped, swimming under the team’s boat and off towards the shore. There were also two highly agitated humpback whales that had been present during the attack, surfacing as close as one body length from the killer whales. They may have been trying to intervene in the attack. They were trumpet blowing and thrashing their flukes. A few black-footed albatross circled over the scene.

13:00 A slick appeared on the water, the calf was dead, but the humpbacks continued to remain in the area where the calf was last seen.

13:00 - 19:00 The seven humpbacks initially stayed in a tight group, later sometimes breaking up into subgroups, then returning to tight formation. Sometimes they approached the killer whales, trumpeting and tail-slashing, flipper waving, spyhopping; they often closely followed the killer whales. They repeatedly dove into the slick area where the calf was last seen. Occasionally they surfaced within a few feet of a killer whale. The closest encounters involved a humpback that turned on its side or back; one humpback raised its head up toward a surfacing male killer whale – keeping it up for some time. A few more humpbacks came in toward the end of our encounter.


- 2 gray whales, a cow and a calf

- 9 killer whales involved in the actual attack – seven females/sub-adults, one male and one calf. Another adult male “Chopfin” (and possibly one sub-adult male) in the area, but apparently did not participate in the attack.

- 2 humpback whales to begin with. Within 25 minutes, at least 7 humpbacks.


The attack happened in an area that was not usual for the killer whales. It’s possible that the killer whales chased the Grays out from Point Pinos (pronounced ‘Pee-nae-oss’) into the deeper water.


There were two family groups of orca together – the 45s and 216s.

1. CA45: Adult female. First seen off Monterey Bay in 1992 with CA46. Always seen with her; probably related.

2. CA45A: The large male. 21 years old (son of CA45)

3. CA45B. Female: ~14 years old (daughter of CA45)

4. CA46: Adult female. First seen off Monterey Bay in 1992 (with CA45). Always seen with her; probably related.

5. CA46C: Young calf, less than one year old (calf of CA46).


6. CA216: Adult female. First seen off southern California in 1998 (with
 Nearly always seen with or near him; possibly related.
 She was pregnant at the time with her first calf. She is one of the most
 commonly sighted orcas in Monterey Bay. Female killer whales give birth
 to their first calf generally between ages 12-15.

7. CA216A: Female. Daughter of CA216. Born in 1999 (13 years old).

8. CA216B ("Jagged"). Born 2003 (9 years old)
 Offspring of CA216. Seen often on our encounter doing headstands nearby, feeding on the 
gray whale calf carcass.

9. CA216C. Offspring of CA216. Born 2007 (5 years old)

Males, not involved in the attack:

10. CA217 ("Chopfin", "Stumpy", “Stubbie”): Adult male. First seen off Southern
 California in 1998 (with CA216). Nearly always seen with or near her; possibly related.
 When first seen, fin had fallen over and completely collapsed (entanglement 
injury). Subsequently 
suffered propeller injury from a boat in 2008. He was full-grown in 1998
 (at least 20 years old): is at least 34 years old.

NOT part of attack group. Seen after attack, about 1/2 mile away. Joined 
 with the CA216s. 

CA46A: young male: not confirmed present; son of CA46)

12. CA46B: not confirmed present; (offspring of CA46)

Before 12 years old it is difficult to sex orca, so some of the sub-adults involved are gender unknown. At around 12 the males will develop long, tall fins and the females will have their first calves. 

These particular killer whales are known to range from Southern California to the Queen Charlotte Islands, Canada. 


At least two of the seven humpback whales involved in the attack had scarred flukes, which indicated they had been attacked by killer whales as calves.

Before our encounter we had seen several.

It is highly unlikely any of these humpbacks would have approached the
killer whales if they were juveniles or calves.

Killer whales are known to attack humpback whales when they are calves, in Mexico. There are also reports of them attacking humpbacks in Monterey Bay. This makes the humpbacks behaviour even more surprising. 

Richard Ternullo of MBWW noted a possible attack of killer whales on a humpback whale calf in 2008; over a dozen humpback whales swam up to 
the possibly injured calf. (*Unpublished account).

On several occasions, killer whales "harrassed" humpback whales. There are no verified reports of killer whales killing (or seriously
 wounding) adult humpback whales.


Attacks can take as long as 45 minutes to six hours (an attack filmed by Blue Planet attack lasted around six hours). In the last few years the killer whales have become more adept and attacks usually last around 1 hour to an hour and a half.

Pods with calves will target gray whales as a learning exercise for their young.

Males do not usually participate in the attacks. These are usually led by matriarchs, who take on different roles. Some females will work on separating the mother and calf, others will be ‘drowners’.

Footage filmed on Thursday 3rd May 2012


BBC Crew:

Victoria Bromley – Assistant Producer

Jamie McPherson – Cameraman

Robin Lewis – Edit Assistant / Second camera


Nancy Black – Boat owner and killer whale researcher. Part owner of Monterey Bay Whale Watch (MBWW).

Alisa Schulman-Janiger – killer whale researcher; Director/Coordinator: American Cetacean Society (ACS)/LA Gray Whale Census and Behaviour Project

Mike Merlo – spotter, working for Monterey Whale Watch 

John Mayer - Captain of MBWW Sea Wolf II (first on the scene and called us on the radio)