#dall's

[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]

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.

[namu-the-orca]

“Game Over”

The Dall’s porpoise has given it her all. First, she followed the golden rule of staying with the pod. Then she got separated.

She’s been smart, cunning, and above all, fast. But she grew tired and the killer whale took advantage of it. It rammed, pushed and shoved her about. It made her insides hurt. Breathing became difficult. Her muscles burned but she kept pumping her tail desperately until it all but refused service. That’s when the whale grabbed her. And now she’s being pulled down into the darkness.

Down, down, down until her lungs will burst, air will escape but none will be outside to replenish the lost breath. She knows this. She feels this in every fibre of her being as she ogles certain death below. But she can no longer bring herself to fight the grasp of teeth on her flukes.

Game Over.

[mbsposts]

Dall Sheep (Ram) with his Tongue Out at the Denver Zoo by D200-PAUL Via Flickr: Best viewed Large on Black According to Wikipedia, the Dall sheep (originally Dall's sheep) is a species native to northwestern North America, ranging from white to slate brown in color and having curved yellowish brown horns. The sheep inhabit the subarctic mountain ranges of Alaska, the Yukon Territory, the Mackenzie Mountains in the western Northwest Territories, and central and northern British Columbia. Dall Sheep are found in relatively dry country and try to stay in a special combination of open alpine ridges, meadows, and steep slopes with extremely rugged ground in the immediate vicinity, to allow escape from predators that cannot travel quickly through such terrain. Male Dall Sheep (seen here) have thick curling horns. The females have shorter, more slender, slightly curved horns. Males live in bands which seldom associate with female groups except during the mating season in late November and early December. Lambs are born in May. Dall sheep can often be observed along the Alaska Highway at Muncho Lake in British Columbia, along the Seward Highway South of Anchorage, AK., within Denali National Park and Preserve (which was created in 1917 to preserve Dall sheep from over-hunting), at Sheep Mountain in Kluane National Park and Reserve, as well as near Faro, Yukon Dall Sheep (Ram) with his Tongue Out at the Denver Zoo

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