Wet Beast Wednesday: false killer whale
Assorted creatures and beasts of the audience, I have been duped. Tricked. Bamboozled, even. I was all ready to write a post on the mighty orca, but this imposter snuck in and tricked me into researching it instead. So this week, I'm covering the false killer whale. You win this time, imposter.
This guy knows he tricked me and he's smug about it.
(Image: a false killer whale poking its head out of the water and sticking its tongue out. It has a bulbous, rounded head with a large snout and eyes on the side. Several conical teeth are showing ad a thick, pink tongue is poking out.)
The false killer whale (Pseudorca crassidens) is actually a dolphin, but the real killer whale is a dolphin too, so I won't hold that against it. False killer whales are closely related to Risso's dolphin, the melon-headed whale (a dolphin), pygmy killer whale (still a dolphin), and the pilot whale (you guessed it, a dolphin). Also dolphins are a subset of toothed whales so this joke was pointless. They are large for dolphins, being the fourth largest species after the orca and two species of pilot whale. Females can reach 5 meters (16 ft) long and 1,200 kg (2,600 lbs) while the large males can reach 6 m (20 ft) and 2,300 kg (5,100 lbs). False killer whales have a similar body shape to orcas, but lack the distinctive black and white coloration, instead being dark gray all over. They have slender bodies with bulges on the front of their flippers and bulbous heads. The bulge on the head contains the melon, a fatty organ toothed whales use to focus their echolocation and vocalizations by acting as a sound lens.
(Image: a pod of 6 false killer whales. They are robust dolphins with bulbous heads and are grey in color. The head lacks the beak seen in may dolphin species and the upper jaw extend beyond the lower one. A single bottlenose dolphin has joined the pod, identifiable by its smaller size and distinct beak. End ID)
False killer whales are found along the coasts and deep oceans of most of the world, from tropical to subpolar latitudes. There are multiple distinct populations that tend to reside in the same general area. These populations can be recognized with unique behavior and vocalizations. They are generally regarded as apex predators, though there have been reports of individuals being attacked by sharks. Their preferred prey is fish and squid, including large fish like tuna. They also prey on other marine mammals, including small or juvenile dolphins and whales. There have even been reports of pods attacking sperm whales. Members of the same pod will share food with each other. Their hunting style is mostly pursuit predation with tactic including ambushes and herding prey into choke points and dead ends. They will also dive for food, and while not much is known about their diving behavior, it appears to be similar to that of related species. Tagged individuals have been recorded going on 12-minute dives and dives as deep as 927.5 m (3,043 ft) though most dives don't go that deep.
(Image: a false killer whale breaching the water, seen mid-jump. End ID)
False Killer whales are highly social animals. As with their close relatives, they live in large pods that typically range from 10 to 20 members and are mostly extended family units led by the oldest female. Males that reach maturity will often leave the pods to seek out mates. Individual families will have their own hunting tactics and vocalizations that are passed down from mother to child. All the females in the pod take part in raising the calves. They communicate with complex vocalizations and body language. False killer whale sociability does not only extend to other members of their species. They are known to peacefully interact with other dolphin species, most notable the common bottlenose dolphin, which whom they will sometimes form mixed-species pods (possibly in reaction to food shortages). False killer whales are also known to respond to distress calls from other dolphin or whale species and help protect them from predators. They have even been recorded helping other species give birth by protecting the mother and helping remove the afterbirth (possibly to eat it). False killer whales have been observed cooperatively hunting fish with true killer whales, working together to herd and capture prey. In these cases, the orcas will take the larger fish while the false killer whales take the smaller ones. Wild false killer whales are reportedly curious about humans and have attempted to share food with divers.
(Image: a false killer whale swimming with a pod of bottlenose dolphins. End DI)
Not much is known about false killer whale reproduction. Based on their relatives, they are probably polygynous, with males attempting to mate with as many females as possible. Males probably provide little to no parental care and calves are raised by their pods. Calves are usually born in late winter after a 15 month gestation period. Newborns can measure up to 2.1 meters (7 ft) and will nurse for between 9 months and 2 years. Mothers will usually not mate until their most recent calf has weaned. False killer whales are one of the few whale species (and few species in general) that can live for a long time after menopause. These elder, non-reproductive females aid the younger mothers in raising their calves, passing on their experience to the younger generations. The maximum age of wild animals is not know, but based on captive specimens, it is up to 57 years for males and 62 for females, with females reaching menopause at 45 to 47 years. Sexual maturity is reach between 8 and 11 years, with males maturing sooner. Male false killer whales have been observed interacting sexually with common bottlenose dolphins, including with males. A hybrid of a male false killer whale and bottlenose dolphin is a wholphin and while extremely rare, they have been observed in the wild.
(Image: a juvenile false killer whale swimming alongside its mother, both seen peeking out of the water. The juvenile is a miniature adult. End ID)
(Image: two wholphins in captivity at Hawaii's Sea Life Park. They look like bottlenose dolphins with shorter beaks and the dark coloration of false killer whales. One has its mouth open. End ID)
There isn't a decent estimation of the wild population of false killer whales, though the population seems relatively stable and they are tentatively classified as near threatened by the IUCN. The Hawai'ian population is considered endangered due to large population losses. They have historically been hunted for meat, leather, and blubber and still are in Japan, where the most common method is using boats to chase them into nets or onshore. False killer whales are known to steal fish off of fishing lines, something that is dangers as swallowing kooks can lead to intestinal blockage or puncturing of the digestive system, both of which can be fatal. It is believed this is the main reason for the decline of the Hawai'ian population. Anglers may also target the dolphins considering them nuisances. False killer whales are know for frequent mass standings and nobody really knows exactly why. Often, whole pods, sometimes hundreds in number, will strand at once and subsequently die. These strandings seem to be increasing due to more extreme weather caused by climate change and possibly an increase in ocean noise. The noise cause by ships has been shown to increase cetacean mortality along major shipping lanes in other species. It has been suggested that the reason whole pods seems to strand together is that their social bond is so strong they will refuse to leave a wounded or stranded member behind. Rescue efforts can help at least some stranded animals return to the water. False killer whales are fairly common in captivity and are housed in aquariums in many countries. They are reported to be more adaptable to captivity than most cetaceans and are intelligent enough to be taught complex tricks. They have been successfully bread in captivity. I generally keep my opinions out of these posts, but I don't think it's really possible to ethically keep cetaceans in captivity outside of rehabilitation and release programs.
(Image: a captive young false killer whale. It has its head out of the water and mouth open, allowing a handler to examine its teeth. End ID)
