Avikan/Biology

Bipedal creatures from the harsh desert world of Kadavan, the Avikan have a leathery skin and have flaps on their heads, shoulders, hips, arms, legs and more, protecting the bodies from hazardous sandstorms. Their long tails grant the Avikan great balance, and the adaptive three-toed feet allow them to disperse their weight over larger areas for easier navigation in quicksand. Small orifices underneath the flaps are connected to multiple sets of lungs, allowing Avikan to blow themselves clean after wading through a sandstorm. The Avikan also have a small dorsal fin, a leftover from when their ancestors were aquatic. (and their planet was a lot less arid.)

The average height of the Avikan sits at approximately 1.6 meters tall. Adult Avikan have been known to reach heights of 2.0 meters, but these are extremely rare cases. The Avikan on board the Nomada have an average lifespan of 110 standard years, where living conditions are actually the best they've ever been for many. While the Avikan living in Terves often reached the same age, nomadic Avikan back on Kadavan generally reached an age of approximately 80 standard years (with pretty high variations based on occupation). Nomen living in some of the harsher Kadavan environments had average lifespans of only 50 years due to the extreme stress placed on the body in these extreme environments.

Their prime years are around the age of 15, though they remain at a pretty high level for much longer than humans. They'd still be pretty fit by the time they're 30 or something around it.

Avikan are actually warm-blooded, which has helped them survive in environments other than deserts (though deserts are still their most comfortable environment). It also allows them to stay active during the cold nights out in the desert, but it also means they have to eat more than they'd have to if they were cold-blooded.

Depending on how cold the planet is, as well as how much water vapour is in the atmosphere (too much might make them sick, but then the atmospheric conditions have to be very specific to their biology anyways). And if atmosphere issues are ignored, they'll generally be able to survive on frigid planets. The deserts of Kadavan reach freezing temperatures at night as well, so their biology is adapted to deal with the cold. They'll definitely need some warm shelter too though, since they do need some warmth: spending a few hours in the cold isn't an issue, but days without heat will be very detrimental to their health.

They can go without food and water longer than many others, as they've evolved to survive on few resources.

Avikan have some sharp teeth, but they are omnivores like us and will have a somewhat similar arrangement of teeth as a result. While, they have a pretty different biology to that of humans, but most of the basic "building blocks" are similar enough that the Avikan could eat some plants from Earth, but it's entirely possible that some plants that are healthy for us are actually dangerous for the Avikan due to the differences in physiology. And for the Avikan, anything that isn't from Kadavan is alien to them, just like how everything that's not from Earth is alien to us.

They have eyelashes to protect against sandstorms, though they have other means of protection too. (such as a special membrane that can cover the eye for additional protection but reduced visibility)

There's far fewer differences between male and female Avikan than between male and female humans, for example. Females generally have slightly shorter flaps all across their bodies, they are very slightly thinner than most males, and their chest is raised a bit (as can be seen in Starbound). They generally have slightly lighter and more vivid colours. To an alien, distinguishing a male from a female can be quite difficult. They have different reproductive organs, of course, but otherwise both genders are quite similar.

The Avikan reproduce somewhat similarly to humans, but they lay eggs instead of having live birth.

Avikan lay a single egg, but all eggs in a Terve are collected and handed off to a group of hatchmothers. They are generally nested in a small pit filled with sand. All children are raised by the same hatchmothers, and it's actually uncommon for an Avikan to know who their biological parents are.

Raised all the way to adulthood by hatchmothers. They take care of the clan's eggs, raise the young and give them a basic education. Once the young ones are old enough to start contributing to the Terve, they start an apprenticeship with an adult Avikan, and usually move in with them until they finish their apprenticeship and start living on their own.

All the clan is considered their family.

Generally stronger than a human, but not as strong as an Akkimari.

The common cold doesn't exist on Kadavan of course, as it's an entirely different ecosystem with different viruses and all, but there are somewhat comparable viruses on Kadavan. The Avikan aren't very susceptible to them though. Earth viruses might very well kill an Avikan. They have stronger immune systems than humans, but alien viruses can still be extremely deadly.

the Avikan don't do very well in humid environments. They get all sorts of health problems from prolonged exposure to high humidity.

Some Avikan are allergic to the common spices, or to specific cacti and such. Allergies are caused by the immune system reacting to substances that aren't typically harmful, and since immune systems are very prone to small issues (due to mutations and other circumstances), you'll find similar issues in pretty much all of the other species too. Some may have less trouble with these issues, and using technology/medication you can often prevent them from being a real issue, but allergies are common throughout the galaxy.

Feet
The Avikan feet are unlike those of any Terran animal. Each leg features three feet – two large ones at the front, and a small one at the back. These three feet act as a tripod which the Avikan can use to either spread or concentrate their weight for easier movement on loose surfaces such as sand. The two large feet on each leg can also be expanded or contracted using three toe-like structures inside the foot, which allow for the same tripod-esque behavior. The toes are not visible on the outside.

The rear sturcture on their feet is for additional support, and allows the Avikan to spread their weight by moving it further back. The two front structures can also be moved more towards the front and the sides - basically the entire foot works like a tripod. The legs are firm structures with two flaps covering the front and one covering the back. The design of the feet is supposed to allow them to walk on sand with ease and prevent the Avikan from getting stuck in quicksand - a very common hazard on their homeplanet Kadavan.

The unique structure of Avikan feet gives them a balance and foothold like no other, so knocking an Avikan off their feet would be very difficult. They can change the way they walk depending on the terrain they're navigating. They contract their feet on harder ground so they can walk more easily (and also quite a bit faster), while on softer soil, like in loose sand or in quicksand, they spread their feet out more so they exert less force per square inch. It makes walking on those surfaces easier, but it does slow them down as they can't run very comfortably with spread-out feet.

Their unique feet decrease overall agility compared to a human, but they gain a far stronger footing in return and can more easily walk on quicksand and other tricky surfaces. They can also fold their three "toes" together to form a simpler foot structure, which helps them run faster.

Hands
Their hands have four long fingers, which you can compare to our index fingers and thumbs - essentially, they have two index fingers and two thumbs on each hand. The flaps covering their hands are intended to protect the fingers and the hands from the unforgiving sandstorms of Kadavan.

Flaps
They protect the more fragile and vulnerable areas of the body from flying dust and sand. In addition, the flaps are one of the features that make Avikan attractive to each other. The shape, length and colour of flaps can be compared to our different hairstyles, with some Avikan preferring shorter flaps while others prefer partners with long flaps.

Vast majority of Avikan have at least one pair of flaps on their head, a bit more uncommon are two pairs or no flaps. It much rarer cases it is possible to find one with three pairs or even rarer four pairs of flaps.

The difference in flap size is mostly due to the different natural roles for the males and females: in nature, males tend to travel further and for longer periods of time in order to hunt and gather, while the females stayed behind to guard and care for the younglings. Because of this, males are generally exposed to more hazardous environments and sandstorms, and the elongated flaps offered some additional protection against these hazards. Flap size, length and shape differs quite a bit between individuals though, and there are certainly females with longer flaps too, it's just less common.

As for the skull length, there's a few reasons, one of which is sexual selection. Females are generally attracted to larger, longer or more intricate head flaps, and a longer skull allows for more space for the flaps. It also gives the brain a little more space to grow, though not very much. This tiny bit of extra space allows male brains to have slightly larger regions for developing hunting instincts and the like.

There's several races within the Avikan species, which were once separated by great distances and evolved to have their own unique features. As the Avikan united, however, these racial divides have shrunk a lot, and there's a lot of genetic variety right now. Besides the general sexual differences, some Avikan have longer or shorter flaps, and there's a variety of shapes (triangular, tapered, blocky and more complex shapes). There's also a difference in the amount of flaps, with the most common being two flaps or four flaps overall. There's some who have even more flaps, though! They're often seen as a little exotic, which can make them especially attractive to some Avikan.

Respiratory system
One more important and rather unique feature of the Avikan is hidden underneath almost all of the flaps on their bodies - they can exhale air from a large number of orifices on their body, such as in their armpits, their hands, underneath the head flaps, the tail end, their hips and even their feet. The purpose of this is to clean the body after sandstorms - they simply blow off all the sand and dust gathered. While they primarily use their mouth to breathe, they can also breathe using these orifices in case breathing through the mouth doesn't cut it. The gill-like structures on their chest serve the same purpose.

Avikan respiratory system is a system of four lungs, divided into two sets. The first set is a set of two large lungs, which function largely like those of humans, with a very high capacity. These two lungs are found in the upper chest area, and are used mainly for breathing. They're are inflated and deflated with the help of a thoracic diaphragm, which can contract to increase the volume of the lungs, drawing air into the lungs. The mouth and the primary orifices are for breathing. The second set of lungs is smaller and is located a bit lower in the body. These can also be used for breathing, but have a smaller capacity and slightly lower efficiency, so they're generally used for cleaning the body. These are deflated most of the time, only being inflated when they are needed. (Not completely deflated, they have a minimum carrying capacity even when not used.)

The mouth and the orifices on the chest are linked directly to the larger set of lungs, and are constantly being used for breathing. The orifices beneath the head flaps, armpits and hands are also connected to the larger set of lungs, while the orifices on the hips, tail end and feet are connected to the smaller set of lungs. All these additional orifices are primarily used to exhale air and are only used for actual breathing in case there's a problem with the mouth or the orifices on the chest. An intricate system of valves allows the Avikan to manually choose which orifices to connect to the lungs and which to shut off. (It also allows them to eat and breathe at the same time by closing the connection between the mouth and the lungs while keeping other connections open.)

Last set of valves allows all the respiratory orifices on the body to connect to the main lungs (the first, larger set) should the secondary set be damaged. (They're the least well protected and are sometimes ruptured during hunts.) This allows the Avikan to keep using those additional orifices even when the smaller lungs are damaged. The orifices on the upper body (the mouth, chest, underneath the head flaps, the armpits and the hands) only connect to the main lungs however - they won't connect to the smaller set of lungs.

An Avikan whose small lungs are damaged can continue living with barely any problems. If one of the large lungs is damaged, the other one is generally still capable of sustaining the Avikan without much trouble as well. If both of the larger lungs are damaged, but the smaller ones still function, the Avikan can still survive, but will not be as active as usual as they have very limited breathing capability. Avikan in such condition are never sent out into the desert, but are given smaller tasks within Avikan settlements or given administrative functions.

One won't be able to suffocate an Avikan by covering their mouth and nose thanks to those other orifices, as they can take in enough air to sustain the Avikan. They vary in size across the body, but are usually around the size of nostrils or a bit smaller. They are often closed when not in use, so they aren't open all the time like human nostrils.