page 71 is here! Ava is….. not having a good time. Ava’s dolphin species (delphinus delphis) is accustomed to living in deep oceanic waters, and they do poorly in captivity - which is why you never see them in marine parks despite them being the most common dolphin in the world (hence their name - Common Dolphins!)
Here’s a tranquil photo of dolphins. Happy hump day!
Bottlenose dolphins (Tursiops truncatus) are very social animals, and often travel and hunt in groups called pods. The most common is a nursery group of 5-20 dolphins made up of females and their calves—although occasionally they will gather in groups (with males) of 1,000 or more. They often hunt together and learn different tricks for catching food from one another (such as using sponges to dig up buried prey) in a kind of cultural transmission.
Two species of bottlenose dolphin in Eastern Australia
These are two older illustrations I recently revamped. I really like how they turned out so I decided to make a little infographic. The distribution and ecological interaction between these two species is very interesting. In many places, two types of Common bottlenose dolphin exist:
• The coastal / inshore type, which inhabits small ranges in (very) shallow water • The oceanic / offshore type, which inhabits very large ranges in deep water
The oceanic type can appear quite close to shore in places where the seafloor quickly drops (here the coastal type is often absent), but in most areas with extended shallows the coastal type will make its home. However, once you enter the range of the Indo-pacific bottlenose dolphin, the coastal type disappears. Indo-pacific bottlenoses completely fill their coastal niche, and only oceanic-type Common bottlenoses remain. This situation is very noticeable in Australia, which these illustrations are based on.
It’s interesting to note though that coastal Common bottlenose dolphins from warmer waters can look incredibly similar to Indo-pacific bottlenoses: including a longer beak, large fins and spotted undersides (which are usually seen as Indo-pacific-specific traits). Curiously, spotting is actually absent on Indo-pacific bottlenose dolphins from the southern half of Australia.
A posse of proper ‘phins And another set of illustrations from last year. This time the “proper” dolphins - not too small, a regular dorsal fin, a good beak. Only the Risso’s is a bit out of line with their cute potheads but otherwise he was all alone. I had lots of fun with all of these. Spinners and Pantropcal spotted dolphin are a delight to draw always. This Pantropical spotted is from the Indian ocean, which tend to have fine black spots and very few white spots. The rough-toothed dolphin gave me some trouble - they’ve such odd proportions they’re hard to really nail down. I still don’t think he fully looks right, but that’s for a different illustration.
The common dolphins on top are very interesting to me: a good example of the diversity found within the single species of Delphinus delphis. Both are forms living around Southern Africa. The “longer beaked” form is larger, more elegant, and has gorgeous clear markings. They live off the Southeast coast, relatively close to shore. The “shorter beaked” form lives more to the west, in offshore waters. They are stouter and often with slightly vaguer markings. One day I’d love to see a study done on all the African forms of short-beaked common dolphins, they are so fascinating. If you move further up the west coast, around Angola, you’ll find a really strange form which is super dark and oddly proportioned. Wonder what’s up with those.
The Indian Ocean humpback dolphin is also an oddball, and a first for me. Love their cute faces and unique body shape. Not just the hump-back but also that strongly keeled peduncle. I hope you’ll enjoy them too!
really confused as to how some cetaceans drink milk from their mothers without flexible lips
ok but now im stuck on imagining whale milk as like…yogurt…and it comes out like a soft serve machine
thank you! I have absolutely no use of this horrifying information other than I will now be haunted by thoughts of whales forcefully shooting toothpaste thick milk into their baby’s mouth like a go-gurt
Give nightmares a little more credit than that, you know it’s going to be yourmouth
Baby cetaceans also make a little tube with their tongue.
You can sort of see the shape in this picture of a bottlefed calf.
The tongue-tube fact is a super important addition!! For many species it is a very necessary part of nursing, because while the milk may be rather viscous, it still goes everywhere if it’s just shot out into the ocean. And this is why cetacean calves have frilly tongues! They use these little tongue flaps to better make a seal around mom’s nipple. The frills decrease substantially with age, though may not always completely disappear. These are tongue flaps of a bottlenose dolphin, who was 4 at the time but still drinking with mom cus she’s spoilt.
For sperm whales the tongue-tube method isn’t very viable because.. well.. have you seen a sperm whale? Instead they just insert their lower jaw into the mammary slit (ouch) and mom squirts milk into their mouth. It’s hard to see in available footage, but I think the babies still make a little tongue-straw to quite effectively suck up the milk. I wonder how much seawater they consumer while doing this?
