#Phocoenoides dalli dalli

[inatungulates]

Dall's porpoise Phocoenoides dalli dalli

Observed by jujurenoult, CC BY

[have-you-seen-this-animal]

[recentlyheardcom]

Orcas have been harassing and toying with porpoises in the Salish Sea for 60 years, often to the point of killing them, but never eating them. Now, researchers think they know why.The perplexing behavior, dubbed "phocoenacide" or "porpicide," often involves several orcas (Orcinus orca) tossing porpoises (Phocoenidae) around for up to five hours, traumatizing and sometimes killing their plaything."I always liken it to a group of friends in a swimming pool and they have a ball between them and the object is to keep the ball above the water," study lead author Deborah Giles, an orca researcher at the University of Washington and research director at the non-profit Wild Orca, told Live Science.The orcas belong to a small and endangered population called southern resident killer whales that live off the Pacific coast of North America. They are fish-eaters, meaning it's unlikely they are playing with porpoises to consume them — deepening the mystery of why these orcas do it.Related: Scientists investigate mysterious case of orca that swallowed 7 sea otters whole"In some cases, you can barely see that there was any interaction," Giles said. "You might see teeth marks where the [killer] whale was clearly gently holding the animal, but the animal tried to swim away, so it scraped the skin."To find out why the orcas engage in this strange behavior, Giles and her colleagues pored over observational records from 1962 to 2020. Porpicide came and went in waves, Giles said, with orcas engaging in the behavior periodically and ditching it again, sometimes for several years. "It's considered a rare behavior, but when it happens, it's notable," she said.There are 78 documented cases of southern resident orcas harassing often very young porpoises, with 28 cases resulting in death from "killer whale-induced trauma," the researchers wrote in the study, published Sept. 28 in the journal Marine Mammal Science.Tossing porpoises around is almost certainly a form of social play, Giles said. But the aim of the game probably isn't to kill, as orcas sometimes continued throwing the porpoises around long after they had died. The activity may strengthen bonds between players and improve coordination and teamwork, according to a statement.Playing with porpoises could also teach orcas valuable survival skills. Baby harbor porpoises (Phocoena phocoena) and Dall's porpoises (Phocoenoides dalli) are similar in size to the southern residents' favorite food — chinook salmon (Oncorhynchus tshawytscha) — so "it's possible that the whales are using it to learn how to chase fish," Giles said.Young orcas and their moms often play with porpoises together, in what could be hunting lessons. "Sometimes they'll let the porpoise swim off, pause and then go after it," Giles said, which could test and fine-tune the orcas' coordination and prey-handling skills.Female orcas may also get involved for another reason. Playing with porpoises might be an attempt to provide care for the small mammals, in what is known as a "mismothering behavior," according to the study.RELATED STORIES—Opportunistic orcas have developed a new feeding behavior that appears to be killing them—Watch orca tear open whale shark and feast on its liver in extremely rare footage—2 liver-eating orcas forced an entire population of great white sharks to flee their home watersThis "might be due to their limited opportunities to care for young" of their own, Giles said in the statement. "Our research has shown that due to malnutrition, nearly 70% of Southern Resident killer whale pregnancies have resulted in miscarriages or calves that died right away after birth."The southern residents' porpicidal tendencies remain somewhat mysterious, Giles said, but the behavior appears to have spread through the population and across generations over the past 60 years."It is possible that porpoise harassing and killing behavior was spread via social learning," the researchers wrote in the study.

[whatnext10]

The Alaskan Glaciers are Beautiful and Impressively Large

The Alaskan Glaciers are Beautiful and Impressively Large shows readers two images of the Aialik glacier, which is just one of many that Alaska is famous for. It explains the blue color of the ice and water and also discusses glacier calving.

Aialik Glacier The main focus of our boat trip out of Seward were the glaciers and the marine wildlife that live on or near them. On our way out of the harbor we were greeted by a pair of bald eagles, which was a great start to the trip. Once we hit the open water we were escorted another part of the way to the glaciers by a pod of Dall’s porpoises (Phocoenoides dalli). I tried to get some…

[namu-the-orca]

The Dall’s porpoise (Phocoenoides dalli)

Some of your may remember the work in progress views for these guys, now finally onto the interweb they go. Another commission for the lovely people at Porpoise Conservation Society, as part of our porpoise species series. Usually one scientific illustration suffices, but with huge sexual dimorphism, two distinct colour morphs and very different calf colouration, no less than six illustrations came into being.

They were lots of fun to paint, and it was interesting to get to know the species better. Truei-type Dall's porpoises occur only east of Japan, while the Dalli-type extends all across the northern Pacific. Within the Dalli-type are again two morphs: in the East the white marking is long, in the West it is short. The change is gradual, and find their extremes on either side of the Pacific. Dalli- and Truei-types are not definitively separated either: a Dalli-type female from the Eastern Pacific was once found carrying a Truei-type calf.

I also tried to show as much individual variation as possible, while still keeping the illustrations representative. Some examples: the Dalli-type male is dotted with fine black spots. Most Dall's have a couple around the edges of their white markings, but some animals are simply covered in them. The four adults also show different degrees of lightness. The Truei-type female is very dark, with almost no white markings to speak of. The Dalli-type female is as light as they get: extensive markings on her pectoral fins, and the normally vague grey tailstock marking is a solid white.

The calves are a different story altogether. Unlike their adult counterparts, newborn and juvenile Dall's porpoises show clear, almost dolphin like markings on their body and especially face. Interestingly, Dalli-type calves display a Truei-type like marking in creamy grey. On very young calves this area can be very light, making them almost look like a Truei-type animal.

Another interesting thing is the males 'manliness'. The more macho a male, the more convex shaped the flukes and the more forward-canting the dorsal fin. For some reason Truei-type males are usually displayed as smaller and more flimsy than Dalli-type males, even though there is no difference in size. So here I reversed the stereotype, giving the Truei-male more manly fins. Another interesting thing is the influence of pose on their perceived shape: although the Truei-male's tailstock seems slimmer than that of the Dalli-male, both have the exact same measurements.

[sitting-on-me-bum]

Dall's porpoises (Phocoenoides dalli) speed through the water at up to 34 mph (54 km/h), according to Whale and Dolphin Conservation (WDC), a wildlife charity that focuses on cetaceans.

Ocean Ecoventures

[antiqueanimals]

Grzimek's Animal Life Encyclopedia, vol. 11, Mammals II. 1972. Illustrated by Peter Barrett.

Beaked whales;

1.) Baird's beaked whale (Berardius bairdii)

2.) Strap-toothed whale (Mesoplodon layardii)

3.) True's beaked whale (Mesoplodon mirus)

4.) Sowerby's beaked whale (Mesoplodon bidens)

5.) Northern bottlenose whale (Hyperoodon ampullatus)

White whales and narwhals;

6.) Beluga whale (Delphinapterus leucas)

7.) Narwhal (Monodon monoceros)

Long snouted dolphins;

8.) Rough-toothed dolphin (Steno bredanensis)

9.) Atlantic humpback dolphin (Sousa teuszii)

True dolphins;

10.) Indo-Pacific bottlenose dolphin (Tursiops aduncus)

11.) Common dolphin (Delphinus delphis)

12.) Striped dolphin (Stenella coeruleoalba)

13.) Atlantic white-sided dolphin (Lagenorhynchus acutus)

14.) Common bottlenose dolphin (Tursiops truncatus)

15.) Risso's dolphin (Grampus griseus)

16.) Northern right whale dolphin (Lissodelphis borealis)

Pilot and killer whales;

17.) Long-finned pilot whale (Globicephala melas)

18.) Pygmy killer whale (Feresa attenuata)

19.) Irrawaddy dolphin (Orcaella brevirostris)

20.) Orca (Orcinus orca)

21.) False killer whale (Pseudorca crassidens)

Commerson's dolphins;

22.) Commerson's dolphin (Cephalorhynchus commersonii)

Porpoises;

23.) Harbour porpoise (Phocoena phocoena)

24.) Spectacled porpoise (Phocoena dioptrica)

25.) Dall's porpoise (Phocoenoides dalli)

26.) Indo-Pacific finless porpoise (Neophocaena phocaenoides)

[cypherdecypher]

Animal of the Day!

Dall’s Porpoise (Phocoenoides dalli)

(Photo by Lance Barrett-Lennard)

Conservation Status- Least Concern

Habitat- Northern Pacific Ocean

Size (Weight/Length)- 127 kg; 198 cm

Diet- Fish; Squid

Cool Facts- No, this isn’t a baby orca. The dall’s porpoise are a very playful species. They generally form pods of up to 12 members, but sometimes the pods combine to create groups of hundreds of porpoises while they play together or feed. They often approach other species of dolphins and even large whales to play. When they hunt, they often do so in large, combined pods, diving for squid and fish up to 500 meters. They prefer the colder waters of the Northern Pacific and have been spotted from Alaska to Japan.

Rating- 10/10 (Would gladly give a hug.)

[kowalskissaki]

313) Morświniec białopłetwy, morświn białopłetwy, morświn Dalla, Dall's porpoise (Phocoenoides dalli) – gatunek ssaka  z rodziny morświnowatych (Phocoenidae). Chłodne i umiarkowanie ciepłe wody północnego Oceanu Spokojnego i przyległych mórz. Preferuje wody o temperaturze poniżej 18°C. Takson po raz pierwszy opisany naukowo przez F. W. True w 1885 roku pod nazwą Phocaena dalli. Jako miejsce typowe autor wskazał Alaskę (ang. „in the strait west of Adakh Island, one of the Aleutian group”). Jedyny przedstawiciel rodzaju Phocoenoides – morświniec, utworzonego przez R. Ch. Andrewsa w 1911 roku. Gatunek nie jest objęty konwencją waszyngtońską. W Czerwonej księdze gatunków zagrożonych Międzynarodowej Unii Ochrony Przyrody i Jej Zasobów został zaliczony do kategorii LC (najmniejszej troski). W okolicach Japonii połowy harpunowe oraz przypadkowe zgony poprzez zaplątanie w sieci do połowu łososi przyczyniły się do znacznego zmniejszenia populacji tego gatunku na tamtych terenach.                                                                             Wyróżnia się dwa podgatunki morświna białopłetwego:                                         Phocoenoides dalli dalli                                                                                         Phocoenoides dalli truei.

[inatungulates]

Dall's porpoise Phocoenoides dalli dalli

Observed by prokhozhyj, CC BY

[inatungulates]

Dall’s porpoise Phocoenoides dalli dalli

Observed by kliewer, CC BY-NC

[namu-the-orca]

Girl’s day out

I just realised I’d never posted the finished Dall’s porpoise painting I made for the Porpoise Conservation Society! High time to make up for that, because it’s one of my favourite things. I had so much fun painting this piece, the lighting, the surface, all those different poses and beautiful faces and markings. The front views were challenging though; Dall’s have very curious proportions that are rarely if ever captured on photographs. It took a lot of tries to get things right.

The painting offers a glimpse into something we will likely never get to see: a Dall’s porpoise nursery pod underwater. Although a striking and conspicuous species, very little is known about Dall’s social lives. Animals that bowride and offer close looks are usually juveniles  – females with calves are wary and stay far away from humans. Nonetheless some proof exists to support the idea that females come together in nursery pods, perhaps for protection or to help each other tend to their calves. 

Here we see females with calves in all stages of life. Near the surface one mother races along with her almost fully grown daughter, in the foreground another dives down with her newborn in tow, and in the background two mothers socialise: one with another neonate, the other an unruly juvenile. Note the juvenile’s almost delphinid facial markings, and the lighter sides that are almost creamy on the calves and have faded to grey on the juvenile. Dall’s porpoises in fact posses markings like most cetaceans, but as adults they darken out so much that the markings become indistinguishable.

[namu-the-orca]

So here’s something fun I got to work on a few weeks back. A t-shirt design featuring all modern species of porpoise - only the two species of finless porpoise were bundled into one, and represented here by the narrow-ridged finless porpoise. Commissioned by the Porpoise Conservation Society of course, because who else could this be for ;) Lots of fun to do, and a nice “warm-up” for my current commission, also for the PCS: a rather more detailed look at one of these species!

[namu-the-orca]

It's been quiet - I've been a bit preoccupied perpetuating porpoises. All for the Porpoise Conservation Society of course ;) After the Vaquita and Burmeister's, we're now onto Dall's porpoise (Phocoenoides dalli). They're an intriguing species, with big differences between males and females, two separate colour morphs, and odd anatomy to begin with. Laterally compressed black-and-white torpedoes.

But they're pretty and they grow on you. The scientific illustrations (four this time! ♂&♀ of both colours) are more or less done, so now the in-situ painting is on the table. It depicts a nursery pod of females with babies of different ages. A unique look into the life of these racing devils, that's normally never visible. The full painting will be a little longer, but for now enjoy these two ladies racing along the surface!

[namu-the-orca]

Week three and no birds in sight! Is this a milestone? I think it is. Instead I went for a bunch of deer and water-deer. By which I mean cetaceans. Little known fact but whales and dolphins are not carnivorans (despite what their impressive teeth may suggest). Rather they are placed within the order of the even-toed ungulates, along with your familiar deer, antelopes, giraffes, pigs and what have you not. Hippos are their closest living relatives and, like cetaceans, they use a form of echolocation. 

I’m very, very happy with how these turned out and I hope you’ll like them too! As before, all are available. Check my website for more info or message me if you’re interested :) Also, even with an extra painting I managed to avoid all the good suggestions from last week - sorry everyone, but they are noted down and I will get to them sooner or later!