Another Orca Quiz

Answer: Yes

Surveys of different populations showed that only around 2-5% of wild orca dorsal fins have any significant bending, with total collapse being even rarer. It isn't understood why wild orca fins droop, and there are several different theories as to why captive orca fins do.

One theory suggests that since they spend a lot of time close to or above the surface, sun degrades the collagen in their fin. Another theory suggests that the water pressure from constant swimming and movement helps keep the collagen strong, and captive orcas are denied this movement, leading to collapse. The swimming in circles around a tank may also put unnatural sideways force on the fins. Other theories suggest dietary changes or reduced blood pressure from lack of movement may contribute.

Answer: No

There have been no recorded deaths caused by wild orcas. In fact, when they encounter us in the wild, they seem to show curiosity towards us, often calling to family members to come and see. They also sometimes bring dead or weak animals, placing the food in front of the person and floating slightly further away, watching.

It isn't known why they do this, but it may be some kind of offering.

Answer: Wearing dead salmon on their head.

This "salmon hat" fad has only been observed twice, and tends to be short lived. It also seems to spread throughout neighbouring pods, giving evidence to the theory that it is a cultural phenomenon. It is often displayed by some members of a pod first, and mimicked by others. Another theory suggest it may be a display of food availability, or perhaps a form of play.

Answer: Carrying them on their rostrum.

Orca mothers have been seen carrying their dead calves on their beak for days at a time, picking them up if they are dropped. A well-known incidence of this behaviour occurred in the southern resident orcas of the northeast Pacific. An orca, known as Tahlequah, or J35, was seen carrying her stillborn calf for 17 days. Towards the end of this period, she began to look malnourished, and other pod members exhibited concern for her.

Other orcas took turns carrying her calf so she could rest. At the end of the 17 days, she released the calf, rejoined her pod, and began eating again after carrying her for 1,600 km (994 miles).

Answer: Transients mainly eat mammals, residents mainly eat fish.

Transient orcas, also known as Bigg's orcas (after Michael Biggs, a famous orca researcher) are larger than residents and mainly eat mammals. They are the orcas in nature documentaries who work together to drown a large whale, or beach themselves to grab seals. They tend to have larger home ranges, swim farther, and have smaller pods.

Residents mainly eat fish, such as salmon or herring. They are slightly smaller on average, and often have an open saddle patch rather than a closed one seen in transients. They often have larger pods, smaller ranges, swim less and often interact with humans who are fishing.

Answer: Diatoms

Orcas that live in the Antarctic or have been there in the past month often have a yellow or brown film of diatoms on their body. This is a large group of many algae that produce 20-50% of the oxygen generated in a year. While orcas usually slough their skin at a regular rate in warmer waters, they don't do this in cold waters, which allows the algae to build up.

It is thought that they don't slough their skin in colder waters because of reduced blood flow or attempts to conserve energy. When these orcas return to warmer waters, it takes roughly a month for them to have a new layer of skin, which will make them algae-free.

Answer: Their slanting eye patches.

Type C orcas have eye patches that slant upwards at an angle. They are the smallest ecotype of orcas. This type of orca lives in the Antarctic, so it is often tinged yellow or brown from the diatoms that flourish in the cold water. The only prey they have been observed eating is Antarctic cod.

Answer: True

One of the most famous instance of this is with the orcas named Port and Starboard. They are unique in that they are wild, but they have collapsed dorsal fins. They are named for the way their dorsal fins collapse (Port's to the left, Starboard's to the right). They are transient orcas, meaning they eat mammals. However, upon their entry to False Bay in South Africa, they began to hunt sharks, most notably great whites.

They would kill the shark, eat its vitamin rich liver, and discard the rest of the corpse, which would often wash ashore. The main theory as to why they began to prey on sharks is that sharks are easier prey then more intelligent whales, and give more nutrients. They first ram the sharks, to turn them upside down, which puts them in a catatonic state. They then begin eating the shark while it is still alive.

Answer: True

By 2024, there were only 74 southern residents left. They are fish-eaters, tending to hunt mainly salmon, but also some herring and rockfish species. Moby Doll, one of the first captive orcas to be studied for the sounds she made, was a southern resident. Granny and Ocean Sun are other members of this population - they are some of the oldest known orcas.

Answer: False

The largest male orca recorded was only 9.8 m (32.2 feet) and 10,000 kg (22,046 lbs). The largest female orca was around 8.5 m (27.9 feet) and 7,500 kg (16,534 lbs). However, males are on average 6-8 m (19.7-26.2 feet) and around 6,000 kg (13,227 lbs), and for females, 5-7 m (16.4-23 feet) and up to 4,000 kg (8,818 lbs). At birth, calves are around 2.4 m (7.9 feet) and 180 kg (396 lbs).