Oddity Ark #89 (269) Walrus

Happy Valentine’s Day, let’s celebrate with an issue about an animal that walks with its teeth. And if you want to request an issue on an amazing animal, fabulous fungus, perplexing plant or awesome paleofauna, don’t hesitate to leave a request in the comments.

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Oddity Ark #89 (#269)

Domain: Eukaryota

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivoria

Family: Odobenidae

Genus: Odobenus

Species:rosmarus

Related Species: The walrus is split into two sub-species; the Atlantic walrus (O.r.rosmarus) and the Pacific walrus (O.r.divergens). Walruses are the last surviving members of Odobenidae. (1).

Range: Walruses are found within a ring around the Arctic Ocean off the coast of northern Russia, the Bering Strait between Alaska and Russia, Canada’s Atlantic Islands and Greenland.

IUCN Status: Walruses are currently listed as ‘Vulnerable’ by the International Union for Conservation of Nature (IUCN).

Tusk Tusk

The walrus is one of the largest pinnipeds, behind only the two species of elephant seal (Mirounga species), reaching a length of up to 3.6m and a body mass of 800 to 1700kg in weight. When on land, walruses can turn its rear flippers frontwards, and as such walks like the eared seals, such as the Stellar sealion (Eumetopias jubatus) although its greater mass means its not as agile or as fast when moving on land. When traversing from water to land the walrus uses its tusks to help pull it up ledges. Walruses are scarcely furred, instead relying on its blubber reserves which is approximately 15cm thick, to maintain their body heat. Due to a large amount of surface level blood vessels, walruses appear white when swimming, due to the blood vessels constricting to conserve body heat close to their bodies core.

Walruses navigate using the vibrissae, a mat of short bristly hairs that are used for detecting vibrations of prey in the sea floor. While it was once thought that walruses used their tusks for digging, studies of the abrasions on the tusks show that this was not the case, and later observations showed the animals using its front flippers and pressurised jets of water spat into the sediment to uncover prey (2), most notably clams that make up almost 97% of the Pacific sub-species diet (3). The clam is extracted from its shell using its lips to make an airtight seal and withdrawing its tongue to create a vacuum that sucks the edible part of the bivalve into its mouth. Adult walruses are largely immune to predators due to size and the animal’s large tusks, with both polar bears (Ursa maritimus) and orcas (Orcinus orca) only occasionally targeting this species, with battles between polar bears and walrus being long, protracted and may result in fatal injuries for the predator.

Mating in walruses occurs in February, with the males surrounding a female rest spot and calling from the water, with the females choosing the male with the best song. Gestation in walruses lasts 16 months, with the calves weighing between 45 and 75kg when born and are able to swim almost immediately after birth. Calves are nursed for a year before being weaned, with walrus milk having a lower fat and protein content than other species of seal, resulting in a lower growth rate than other seal species (4). Walruses reach sexual maturity at five years of age, and gather in same sex herds outside of the breeding season, although younger males walruses typically don’t breed until they reach a size comparable do the larger bulls of the bachelor herd.

Spotlight #6 – Let’s talk about non Heteronormative Animals.

One of the major things I hear certain people say about the LGBTQ+ community, is that such relationships are unnatural. As someone who is part of that community it is dehumanising when that, and worse allegations are flung at you. But here’s the thing, the natural world is plenty of animals engaging in non-heteronormative relations. Before we look at some of these examples, we need to explain what a sexual relationship is. In some occasions when two animals appear to be mating, it sometimes is simply one animal displaying dominance. To qualify as a sexual relationship, we need to look for courtship displays, shared affection, pair bonding, co-parenting and actual sex. With that criteria established we are off to New Mexico for our first example, one that has previously been brought up, the New Mexico whiptail lizard (Aspidoscelis neomexicanus).

The New Mexico whiptail lizard is as a species, completely female, reproducing through a process known as parthenogenesis, where the female creates a clone of herself. As such New Mexico whiptail lizards do not need sexual reproduction to produce viable offspring, they still appear to need sexual stimulation to begin ovulation (5). New Mexico whiptail lizard sex does not consist of a simple mounting but involves biting and wrestling their sexual partner to a standstill. Lizards are not the only animals to engage in female-on-female relationships, within Laysan albatrosses (Phoebastria immutabilis) on the island of Oahu, thirty-one percent (6) of the population were in same sex relationships, exhibiting the same courtship and affectionate behaviours as more conventional couples, as well as banding together to hatch an egg, usually coming after a brief tryst with a male albatross. While same sex couples typically rear less chicks then more convention pairings, male albatrosses are more likely to die when foraging for food for both mother and chick, meaning a chick raised by two females may have a better chance of surviving until it fledges, and then becomes independent from its parents.

Perhaps with the sneaky affairs with male albatrosses to get eggs, the Laysan albatross could be called bisexual. In the main body of the issue, it was stated that walruses gather in bachelor herds outside the breeding season and that young males typically are locked out of breeding by larger individuals despite reaching sexual maturity, sometimes for as long as a decade (7). As such most walruses exhibit bisexual tendencies outside the breeding season, primarily close affectionate behaviours including sexual stimulation. As surprising as bisexual walruses may be, I suspect no one would be surprised that dolphins may also have bisexual tendencies. Amazon river dolphins (Inia geoffrensis), like walruses live in bachelor and bachelorette groups and practice non reproductive sex such as genital rubbing, and in the case of male dolphins’ sexual penetration of the blowhole. Such behaviour is not limited to males of the same species, male Amazon river dolphins have been recorded performing sexual acts, including blowhole penetration, with male tucuxi (Sotalia guianensis) another species of freshwater dolphin (8).

Moving on from bisexual dolphins, we need to talk about vampire bats (Desmodus rotundus). Female bats typically gather in maternity roosts, leaving males to gather in satellite bachelor roosts. Vampire bats already share blood meals with individuals that have been less successful, and males also perform fellatio or ‘male on male genital licking (9). These sessions of fellatio are carried out in separate sessions from allogrooming, where social animals groom each other are sexual rather than merely just social behaviour. Perhaps one of the most studied homosexual relationships on non-human animals is the relationships of lions (Panthera leo). Male lions, prior to establishing prides of females typically live in coalitions of same sex animals. Within these coalitions, males practice affectionate headbutts and allogrooming, cumulating in mounting and thrusting (10). Male lions are not the only ones engaging in same sex relationships, lionesses also engage in same sex stimulation.

Closer to home, we turn to one of our closest relatives, the bonobo (Pan paniscus). Bonobos live in matriarchal led groups that uses sexual activity as a way to strengthen social bonds, as conflict resolution and post conflict resolution. Both males and females practice same sex relationships, and the only non-human animal that practices tongue kissing (11) and face to face sexual relationships (12). Sexual activity can be stimulated by something as simple as finding food, and animals don’t discriminate against gender or age, although mothers and adult sons avoid copulation. In comparison to their closest relatives chimpanzees (Pan troglodytes), bonobos are far more peaceful, rarely engaging in aggressive conflict.

Finally, we need to talk about transsexuality and western marsh harriers (Circus aeruginosus). Upon reaching sexual maturity, male and female marsh harriers have very different plumage patterns, with male marsh harriers having grey plumage while the females are typically brown. Male marsh harriers are territorial, attacking any male that comes near their nest, while females rarely attack other harriers (13). On the flip side, male marsh harriers do not mob egg predators that enter their territories, with females birds actively engaging predators such as magpies (Pica pica) and carrion crows (Corvus corone) (14). Within marsh harriers, 40% of males exhibit female plumage upon reaching sexual maturity (15). Not only do these birds look like females, they act like them too, rarely attacking males that enter their territories and engaging in mobbing of egg predators. When these female plumaged males have nests and are protecting eggs or chicks, they do become territorial, but they primarily target females seeing them as rivals rather than potential sexual partners.

Nature is seems, is far from just heteronormative, and is a lot more diverse then first appears.

References

1. www.arkive.com

2. Levermann N, Galatius A, Ehlme G, Rysgaard S, Born EW (October 2003). "Feeding behaviour of free-ranging walruses with notes on apparent dextrality of flipper use". BMC Ecology. 3 (9)

3. Chapter 4.9.8.5: Other Pinnipeds". Alaska Groundfish Fisheries Final Programic Supplemental Environmental Impact Statement. 21 December 2018

4. Fay FH (1982). "Ecology and Biology of the Pacific Walrus, Odobenus rosmarus divergens Illiger". North American Fauna. 74: 1–279.

5. Crews, David (1987). "Courtship in unisexual lizards: A model for brain evolution". Scientific American. 257 (6): 116–121.

6. Young, Lindsay C.; Zaun, Brenda J.; VanderWerf, Eric A. (2008). "Successful same-sex pairing in Laysan albatross". Biology Letters. 4 (4)

7. Fay FH (1985). "Odobenus rosmarus". Mammalian Species (238): 1–7.

8. Bagemihl B (1999). Biological Exuberance: Animal Homosexuality and Natural Diversity (Stone Wall Inn ed.). New York City: St. Martin's Press

9. Riccucci M (2011). "Same-sex sexual behaviour in bats". Hystrix It. J. Mammal. 22 (1): 139–47

10. Bagemihl, Bruce (1999). Biological Exuberance: Animal Homosexuality and Natural Diversity. New York: St. Martin's Press. pp. 302–05.

11. Manson JH, Perry S, Parish AR (1997). "Nonconceptive Sexual Behavior in Bonobos and Capuchins". International Journal of Primatology. 18 (5): 767–86

12. Balcombe JP (2011). The Exultant Ark: A Pictorial Tour of Animal Pleasure. University of California Press. p. 88

13. Fernandez, C., Azkona, P., 1994. Sexual Differences in Conspecific Territorial Defense of Marsh Harriers (Circus-Aeruginosus). Journal of Raptor Research 28, 23–26.

14. Sternalski, A., Bretagnolle, V. (2010) Experimental evidence of specialised phenotypic roles in a mobbing raptor. Behav Ecol Sociobiol64, 1351–1361

15. Bavoux .C, Burneleau. G and Bretagnolle. V (2006) Gender Determination in the Western Marsh Harrier (Circus aeruginosus) Using Morphometrics and Discriminant Analysis, Journal of Raptor Research 57-64, 8

Picture Credits

1. R.6a006a312b9103954255294fbf7852b0 (2309×1298) (bing.com)

2. d4220cf6c46e385c9b384654f545cd09.jpg (990×742) (pinimg.com)

3. OIP.gjEUVlcY5gYAZFws3GzbXAHaE8 (474×316) (bing.com)

4. New-Mexico-Whiptail-Mating.jpg (800×472) (reptilefact.com)

5. amazonriverdolphin.jpg (800×800) (rainforestanimals.net)

6. western-marsh-harrier-bangalore-india-w-1500.jpg (1500×2100) (thainationalparks.com)

Happy Valentine’s Day to everyone and everything out there. Next week we have another request issue from @cbishop. And if you want to see more amazing animals and plants, please check out the Oddity Arkive or past issues. And if you want even more animals, please check out dearly departed Impurest Cheese’s Guide to Animals which can be found here, or on the blog of Eros’s pincushion @ficopedia.

If you still have a yearning for learning, please check out the master list of Mr Monster’s Martial Arts Journey.

@cbishop, @mrmonster, @lemillion, @spareheadone, @chino_xl, @goldpool, @whathappened, @yejj,@arranvid, @goodkarma, @jacdec, @steve40l, @cambatta, @arctika, @eisenfausteand @officialtopg

Happy Valentine's Day everyone!

Hey cool thread, Walruses are cool.

@arctika: Yeah they are pretty cool, seals as a whole are an interesting group.

@sundown89: As a kid my folks took me down to Florida we went for vacation a few times, they had some seal and dolphin shows. They seem like smart animals with the tricks they can do.

@arctika: Well the US Navy has developed simple multiplayer video games for their sea lions to play when there not working so they may be smarter then you think.

As for dolphins…they are to smart, to the point where we are seeing some of the darkest supposedly human traits appear in them, which may mean they are not solely human traits at all.

That's interesting about them playing video games. Dolphins are smart animals for sure. What kind of dark traits?

@arctika: So dolphins play ‘volleyball’ in the wild and they use baby nurse sharks as a ball. Taking into account that even adult nurse sharks aren’t a threat to even baby dolphins and this is the least of their bad behaviour.

Dolphins practice infanticide which is normal in the animal kingdom but what happens after that is far from normal. Once the calf is dead the killer (maybe the mother, maybe a random male or female dolphin that stumbled across the mum and baby) will sexually assault the corpse. Sometimes they even start with the sexual assault which leads to the calf drowning.

Male dolphins practice gang rape, splitting a female off from her herd, brutalising her until she won’t fight back and then take turns mating (for want of a better word since it’s likely the female is not yet sexually mature) until they are bored with her, with those males not actively involved acting as blockers to prevent her escape.

It’s not just dolphins that are targets for dolphin sexual aggression. Seals, sharks, porpoises, sea turtles and humans are all valid targets too. Which brings us onto dolphin genitalia, a 4m bottle nosed dolphin has a meter long penis with essentially a grappling hook on the end. Having seen one before (wild dolphin pleasuring himself) I really never want to see one again.

Oh and then there’s the torture. Orcas play with their food (still alive) launching them into the air for fun because your 200kg snack really has a chance fighting off its 5000kg attacker, especially when your first attack crippled. Smaller dolphins do something similar, they will toss a fish on land and watch it suffocate and then just leave it there.

Finally kind of but not really racism is also practiced. Some bottle nosed dolphins go out of there way to kill harbour porpoises and then of course sexually assault their corpses.

Dolphins are not our friends, they are usually not coming to save you when your drowning in the ocean, at this point you probably can guess what they want…

Oh wow that's quite a detailed explanation. I had no idea they were that aggressive. The part about the masturbating dolphin was a little amusing though, that I've seen quite a few other animals practice in some videos (specifically monkeys, apes and tossing their poo as it were) but the parts about the sexual aggression with other animals and females etc that definitely sounds aggressive. I used to think they were such sweet creatures, perhaps they still are but I guess their nature is more aggressive at times. Orcas I remember hearing are aggressive for sure. There's a movie called Orca, where this family of them the mother and child get killed by humans and the father gets his revenge. Yeah the ocean seems like a scary place, though I did recall reading a story about a whale helping a human or letting humans help them or something. I forget the kind of whale specifically just a story I recall from way back.

@arctika: It should be noted that this is not being carried out by every dolphin, just like murder is not carried out by every human. Orcas for the longest time have been less aggressive towards humans then smaller dolphin species, although three orcas have started trying to sink ships off Portugal's Atlantic Coast apparently for fun (or possibly because they were protecting their hunting grounds). As for whales, I don't remember the incident you are talking about but I'd wager its probably a humpback whale, they have been known to protect other animals such as seals and humans from sharks and orcas.

I don't find the ocean or its inhabitants particularly scary but then I am weird like that.

Yeah it was probably a humpback. Have you done a whale thread? I wonder which is the most dangerous whale, whaleshark? Humpback? I remember as a kid I always though an Orca always reminded me of a hybrid of a Whale mixed with a Dolphin but a giant one haha. I'm not a great swimmer so that's apart of it on my end. When I was a kid and used to swim on the beach, I'd always keep my eye out for sharks so I'd never go far out as well as jellyfish. We'd see them washed up on the shore all the time. I remember my dad telling my friends and I don't touch them. One of my friends had this thing with "touching everything cause it looked cool" I recall being skeptical.

@arctika: Well all dolphins and porpoises are whales but not all whales are dolphins, so anything and everything we call dolphins are just whales. Essentially its the law of monophyly, where you also a member of every clade above you. That's why orcas look like they are between being whales and dolphins, it's because they are effectively both a small whale and the largest member of the dolphin family.

I used to sea kayak but its been a while since I've done it, but from my observations with our local orca pod, they generally are pretty chill but each pod is different. For example this pod is primarily fish eaters, they have very little interest in hunting marine mammals even though they defiantly could. In essence its cultural evolution, rather than genetic evolution that has led them to this dietary preference.

Your dad is right, don't poke dead things on the beach. Not all of it is dead, and jellyfish can still sting after death for a period. Plus there is this...don't touch this if you see one.

I will bump the respective IGTA, OA and TN issues Imp and I wrote about cetaceans for you, so you can browse them at you leisure.

I see so they're within the same family tree and subspecies etc? That's interesting but definitely makes sense.

@arctika: Yep one day I will follow through on the threat I made about explaining taxonomy which will clarify things even more.

Nice. That's a great point with the Orca looking part whale/part dolphin regarding it's looks.

@arctika: Thanks, Orcas are the only member of their subfamily, but there are plenty of other dolphins that look whale like such as pilot whales and Risso's dolphin.

Yeah that second one definitely has features from an Orca and Dolphin, that's cool.

@arctika: Well it is part of the sister taxon so that's not surprising.

Yeah that makes sense.

My sister and I think that walruses are funny XD

@arranvid2: They are fairly amusing animals, but then I find seals in general quite funny and charming.

@sundown89: "Eros’s pincushion!" Ha! <sigh> I must be immune.

I am so behind on this and Oddity Ark. Sorry, man. I've been dealing with some stuff.

@ficopedia: Nae problem you’ll get there when you get there.