Yautja

The yautja are a hunting race from the furtherest reaches of the universe. The males of the species live for the thrill of the hunt.

Yautja are best classified as mammal-like reptiles; this means that they are warm-blooded creatures with a reptilian appearance, which may hint at a synapsid evolution. Yautja are adapted to warm climates and can with stand temperatures up to 250°C (482°F).

Although yautja are warm-blooded they cannot live in a cold climate. If an unprotected yautja were to be exposed to temperatures below 10°C (50°F) it would probably die within a few hours.

In the yautja race, the females are bigger then the males. Yautja males are approximately 2.20 to 2.70 meters (~7.2-8.8ft) tall; females are estimated at 2.50 to 3 meters (~8.2-9.8) tall.

Biology
The yautja circulatory system can be divided in to 3 circulations:

1. From the heart to the lungs 2. From the heart to the body 3. From the heart to the brain

In the yautja circulatory system the brain has a separate circulation. This allows for a higher blood pressure in the rest of the body without damaging the fine network of blood vessels in the brain. This allows the yautja to live with blood pressures that would normally kill a human.

The ability to create and survive such high blood pressure has certain advantages. The blood can be transported through the body faster and thus oxygen and other nutrients are transported quicker and waste products are removed faster.

This special circulatory system is part of why yautja are so strong. It allows the organs and muscles to work harder and thus increase the muscles capacity.

The yautja 3-part heart consists of 2 auricles and 3 ventricles. The blood is pumped from the right side of the heart (seen on the left of the heart schematic in blue) through the lungs. From there it goes back to the heart and into the left auricle (seen on the right of the heart schematic in green). From here it goes in to the 2 ventricles that are connected to it. One pumps it into the body and the other pumps it into the brain at a much lower pressure. When the blood has gone through the body and the brain it goes back to the right side of the heart and the cycle starts again.

The yautja skeleton is stronger then our own, although the material it's made of isn't stronger then the material our own bone is made of. The yautja skeleton is stronger however because of its firm build. The bones are much thicker then our own and also much more compact which makes them heavier.

Yautja don't seem to have the problem of calcification which makes bones more fragile. Whether this is natural or because of the yautja have a treatment for it is unknown.

The yautja muscular structure is in construction quite similar to that of humans.

The reason yautja are much stronger is due to the fact that the muscles have a much more efficient nutrient and waste product transport. This is because of the yautja 3-part heart.

The greater strength is also created by the higher percentage of muscular tissue per kg of body weight and the fact that yautja are bigger then humans.

We know very little about the yautja nervous system. We know that the yautja have much faster reflexes then us and that it is probably roughly the same as our own.

Unlike humans, who reproduce the whole year round, the yautja seem to have a mating season. This makes sense since males and females live separately most of the time and males are often light-years away from home, hunting on other planets.

Interestingly, the yautja mating season does not seem to be written in stone, as both males and females are capable of reproducing outside the mating season. Normally creatures who have a mating season can only reproduce during the mating season. Yautja it seems can reproduce the whole year round but won't.

There are 2 theories as to why this behavior exists:

1. Mating season is part of their culture and is sustained for religious reasons or for the sake of tradition.

2. Mating season is simply convenient because of the earlier mentioned distances between males and females.

Mating season is a 30 day period which occurs roughly every 400 days. During the mating season the males try to mate with as much females as they can. The high ranking males will attract enough females just because of there status. The males that are lower in rank will have to fight for there females. This behavior is probably millions of years old. It dates back to a time that the first yautjaoids where beginning to evolve. It is likely that the flat crests on top of a yautja's head developed for the purpose of attracting a mate. During mating season a successful male can mate with up to 20 females. This only happens to really successful males these are real top hunters. For the over-all population 2 or 3 females is really a lot. But because of this type of distribution of females a lot of males are left without females. This is also the reason most males don't mate for the first time until they are at least 50 to 60 years old and have acquired a reasonable trophy collection. Some times it doesn't happen at all for instance when a male is seen as unfit for breeding and he is castrated or when the yautja becomes one of the eta because of dishonor or cowards. Sometimes the lowest hunting males are also unable to acquire a female these frustrated males may turn on their subordinates.

The yautja male reproduction system is similar to that of a human male. The female reproduction system differs quite a lot from that of humans. Although the outside appearance of the female reproductive organs is similar to that of a human. The inner workings are quite different. Although yautja give live birth the babies develop in an egg like structure. A similar type of reproduction implied by some snakes which hatch there eggs inside there bodies. This type of reproduction is called ovoviviparous (Ovoviviparous having non-shelled eggs which hatch internally of the female.)

In yautja this type of reproduction has evolved it self into something much more specialized then just the hatching of an egg inside the body.

On the ovary only one egg at a time ripens. It takes 40 and the egg will be ready to be fertilized for the next 70 days. Although the egg is ripe and ready to be fertilized it is not jet fully grown, It will only grow to its full size when it its fertilized. The egg is fertilized whilst still on the ovary which will allow it to develop further. When the egg is fertilized the yoke which will have to support the growing yautja fetus, starts to grow in mass. The next 80 days will be crucial. In this period of time the yoke grows to its full size and the fertilized egg starts to develop into a fetus. In the mean while the walls of the "womb" start to produce a thick coating of most holding slime and blood vessels. This coating will later on provide the growing fetus with oxygen and fluids and a means of removing the carbon dioxide and other waste products. Before this time the egg gets its oxygen and water from the egg white. After the first 80 days the egg has grown to its full size and detaches it's self from the ovary. The womb coating will cover it completely within days. The fertilized egg as now become an embryo and the basic shape of the yautja has revealed it's self. The embryo is attached to the yoke by an umbilical cord it will get its food from here for the next months. From now on the embryo will keep growing until it has become a baby ready to be born.

Nearing birth the yoke has shrunk to the size of a Ping-Pong ball although it isn't round. In the next few hours the yoke will merge with the embryo's abdomen. When the child is born the yoke can still be seen as a small elongated bump on the stomach with a slightly different color as the rest of the body.

This type of reproduction has definite advantages over actually laying eggs. The eggs can grow much larger because they don't need a hard shell. The yoke can grow much larger because the amount of egg white needed is reduced immensely. The womb coating provides the oxygen and water that used to be provided by the egg white.

Yautja lungs take up oxygen more efficiently then human lungs. This is necessary since Yautja breath an atmosphere which has 2 to 3% less oxygen then our own atmosphere. Their atmosphere is rich nitrogen and has a high humidity, 70 to 90% humidity is normal.

Although yautja can breath the earths atmosphere they can't breath it for very long 2 to 3 days maximum. This is why they always have breathing gear with them.

For as far as we know yautja lungs are basically the same as human lungs. Yautja lungs are more efficient in taking up oxygen because their lungs have more blood vessels and have a bigger lung capacity.

Yautja skin is reptilian in origin although at first they appear to have no schales. Over millions of years the scales on have become so fine they are now nearly invisible.

The skin is also extremely though and can withstand temperatures of up to 250°C without being burnt. it also gives good protection against small caliber weapons (9mm) like a bullet vest.

The skin color has many variations. Ranging from brown reddish colors right through to bluish-greenish colors. This large variety of colors and patterns probably came about when the yautja started to settle on other planets. Presumably their ships where not as fast then as they are now and it would have taken some time just to get to an other solar system. Yautja on other planet would have been almost cut of from the rest of their species. These yautja would then start to adapt to this new environment producing this great variaty of colors and patterns.