They do go after seals, otters, sealions, dolphins, penguins, various sea birds, larger fish like sharks and even the smaller whale/dolphins including humpback whale calves. Which likely explains why humpbacks get involved when orcas hunt.

They have also been known to offer parts of the above to humans as peace offerings. Initially, they offered whole animals, then decided humans need it cut up, and then they tried kelp and seaweed in case humans are vegetarians.

There is a recent paper published on this type of behaviour where orcas offer food and other objects to humans, and though it is fairly rare, it has been seen in orca populations around the world. A good chunk of these encounters happened with people swimming in the water.

Orcas in some encounters offer whole prey, while in other encounters they offered only parts of prey, and in a couple of encounters they offered kelp/seaweed. There didn't really seem to be a progression from whole prey to partial prey to seaweed in these encounters (at least most of them); these objects and prey varied between the different individual orcas present in separate encounters.

The object-sharing behaviours are primarily considered exploratory behaviours by the authors of the paper, because orcas are observed usually pausing and waiting for a short amount of time to see how the humans react to their actions. Thus the orcas are likely "testing" the humans.

Possible reasons for the orcas to engage in this behaviour are stated by the authors of the paper.

"Offering items to humans could simultaneously include opportunities for killer whales to practice learned cultural behavior, explore or play and in so doing learn about, manipulate or develop relationships with us. Given the advanced cognitive abilities and social, cooperative nature of this species, we assume that any or all these explanations for, and outcomes of such behavior are possible. These cases suggest that societies of generalized reciprocity are prevalent in some populations of this species and indicate that as in humans, sharing is a cultural by-product used by killer whales outside of their own species to explore relationships within their respective environments."

The behaviours of orcas offering food and other objects to humans are likely just extensions of well-documented cultural behaviours where orcas often share food with each other, likely forming and strengthening bonds between each other. The researchers have thus labeled the behaviour as a form of "generalized altruism," where the orcas extend this behaviour across species towards humans as well. This also may indicate that orcas display theory of mind towards humans, as is stated in an article.

However, authors of the study on orcas trying to share food with humans also strongly recommend seeking out such close interactions or encouraging relationships to develop, due to the potential for either of these two species to harm each other.

The potential for short-term proximate benefits of offering prey to humans may outweigh any immediate associated costs for the whales, but due to the potential for either species to engage in behavior that is harmful to the other, we strongly recommend against seeking out such interactions or encouraging relationships to develop by reciprocating when they do occur, unless permitted to do so with appropriate ethics approvals.

I live an hour from Monterey Bay Our humpbacks are migratory and we rarely see orcas. They are here, but I have spotted humpbacks and greys perhaps a dozen times, otters more commonly, sharks while diving. Never even heard anyone talk about orca sightings here. In Puget, sure, but not down here.

Bigg's (transient) orcas are indeed significantly more frequently spotted in the Salish Sea compared to Monterey Bay, but there have been a fair amount of sightings from whale watching companies, particularly in April and May. The California Killer Whale Project has counted encounters of Californian Bigg's orcas orcas each year from 2021 to 2024. Sightings per year range from 70 to 95.

Non-migratory orca pods are more likely to eat fish that migratory pods.

Do you mean resident vs Bigg's (Transient) orcas? They are actually now considered completely separate subspecies. Resident orcas pretty much only eat fish and never have been documented eating mammals, while Bigg's orcas mainly eat marine mammals and have not been documented eating fish, except perhaps sunfish. They have have not been documented interbreeding with each other either.

I wouldn't really call them "migratory" vs "non-migratory." Unlike many baleen whales such as humpback whales, many orca populations often don't make very long migrations. Bigg's (transient) orcas often have larger ranges than resident orcas do and can be more unpredictable in their movements, but the

but they are opportunitist predators and don't limit to fish

Most orcas aren't really known for being highly adaptable and opportunistic predators. Quite the opposite in fact; they are often conservative and highly specialized predators that learn what to eat from the mothers.

Though orcas as a whole "species" prey on a large amount of different species, they belong to very different populations, and each of these populations has its own unique culture. Due to these cultural reasons, orcas are often unwilling to change from their pod's/community's diet. Culture in orcas does not only determines the different learned diets and hunting techniques amongst different orca populations, but it also determines their different communal social structures, vocalizations, traditions, social norms, play activities, and more amongst different orca populations.

The different dietary preferences found in orca communities and pods are passed down generations (culturally transmitted) within an orca population. Specific diets form a major part of the cultures of each unique orca community/population. Culture seems to be very important to orcas, and thus orcas will rarely stray outside of the diet they are taught to eat by their podmates. In addition, even to mammal-eating orcas, humans likely simply do bear any resemblance to the various mammals that these orcas are familiar with. Thus, orcas do not recognize humans as potential prey.

This theory has been supported by cases of orcas, both in the wild and captivity, refusing to eat certain prey even when malnourished and/or starving. The endangered fish-eating Southern Resident orcas have essentially been slowly starving due to not getting enough salmon to eat, yet they do not eat marine mammals (despite the high abundance in their habitat) or even certain types of fish that may be high in abundance. Captured mammal-eating Bigg's orcas have also refused to eat fish given to them by their captors even when starving.

Culture appears to be very important to orcas. Culture in orcas does not only determines the different learned diets and hunting techniques amongst different orca populations, but it also determines their different communal social structures, vocalizations, traditions, ceremonies/rituals, social norms, play activities, and more amongst different orca populations.

As stated by whale biologist Olga Filatova:

"Orcas are conservative and tradition-bound creatures who do not move or change their traditions unless there is a very good reason for it. We see that in this population," says Filatova.

Zoologist Dr. Lance Barrett-Lenard also states the following about orca behaviour:

"The fact that killer whales are capable of learning and culturally transmitting complex behaviors, as illustrated by the examples above, does not mean that they are particularly adept at coming up with novel behaviors on their own. Indeed, they strike many researchers, particularly those who have studied them in captivity, as conservative animals - capable of learning practically anything by example, but not prone to experimenting and innovating. For example, captive killer whales are far less likely to pass through a gate or investigate and play with novel objects in their pools than other members of the dolphin family - unless a poolmate or human trainer does so first."

So, even in times of need, orcas can be reluctant to switch from their natal diets.