Terms
These types of orcas are fish-eaters, live in larger pods, and have rounded dorsal fins.
What is resident?
True or false: All interactions between orcas and other marine mammals involve predation.
What is false?
The only potential "natural predator" of a killer whale
What is other killer whales?
According to Jefferson, killer whales had the highest amount of predatory interactions with this species.
Bonus 50 pts: Killer whales had the highest amount of non-predatory interactions with this species.
What is Southern Elephant Seal?
Bonus: What is the minke whale?
According to the chapter, these three moments are the only time orcas would attack larger whales.
What is opportunistically, if their original prey failed, or if the large prey was susceptible (calves slowing moms down)?
These types of orcas are mammal-eaters that live in smaller, stealthier pods, and typically have a pointier dorsal fin.
What is transient?
It is suggested that this sense is used more when attempting to detect and avoid killer whales.
What is vision?
While sightings of killer whales were frequently recorded, this was hardly ever recorded by whalers
What is attacks/predation?
In interactions with killer whales, several cetacean species exhibit this anti-predator response involving tight grouping and coordinated swimming movements.
What is defensive aggregation/milling/tight grouping?
According to Jefferson, another paper (Jonsgard 1968) suggested this regarding orcas and healthy, adult baleen whales.
What is incapable of attacking?
Exhaling underwater and barely exposing their blowholes at the surface to inhale
What is snorkeling?
These three types of marine mammals have been observed attempting to avoid or hide from Killer Whales in shallow water, kelp beds, river mouths, the surf zone, or among ice floe
What is large whales, smaller cetaceans and pinnipeds?
The most active and effective individuals during the actual killing phase of an attack on a large whale
What is adult female orcas?
The 2 species of mammals Jefferson mentions being predated on by killer whales aside from cetaceans and pinnipeds.
What is sea otters and dugongs?
Previously less reported, the chapter offers these as the three reasons attacks on larger whales are now more frequently recorded.
What is an increase in human numbers, enhanced communication/reporting opportunities, and growing interest in cetaceans ?
A whale standing vertically with the entire head exposed above the surface
What is spyhoppping?
This term states that a predator must kill an animal that is regularly taken by that species, and yet not eat part of the carcass, despite the fact that there is free access to it. There is evidence that orcas do this to seabirds and marine mammals.
What is surplus killing?
These three parts of the prey were typically consumed before being abandoned.
What is the tongue, lips, and portions of the ventrum (belly)?
According to Jefferson, orcas are considered to be the number one cause of mortality for this species.
What is the crabeater seal?
According to the chapter, energetic/demographic analyses suggest this.
What is that the smaller marine mammals, even at estimated peaks of abundance, would not be capable of sustaining the transient killer whales in the North Pacific?
A syndrome often observed in ungulates, but seen in a female grey whale as she stopped trying to escape, rolled on to her back, and exposed her ventral side
What is capture myopathy/capture stress?
DAILY DOUBLE! WORTH 2X POINTS!!
T/F: Based on Figure 1, the large the prey, the larger the pod of orcas to attack better.
For the double points: You must explain your answer in the context of Figure 1.
What is false?
This type of evidence supports the belief that most rake-type scars do indeed originate with killer whales rather than other species
What is comparison of rake marks on living whales with the tooth patterns of various potential predators?
3 ways killer whales cooperate to attack.
What is biting to slow movement, lunging on to backs, circling/herding to prevent escape?
FINAL QUESTION!!
Based on everything we've gone over in previous lectures and this week's readings, do you think there is enough evidence so far to support that killer whales did have to switch to pinnipeds and smaller marine mammals as a result of industrial whaling? Or do you think killer whales likely didn't use large baleen whales as a primary source of food to being with?