It's called natural selection. With the addition of specifics, you have many things.
These include competition for things such as food, resources, rights to living space, and most importantly --- dominance. That was why it couldn't understand when it was shot down in the midst of its nightly travels. Had they not, it and its fellow reptilian brethren, made the obvious even more so to these two-legged, wingless ground birds, or was it just that they were not capable of even the simplest logic that all other living things in the world had inside? The Night Fury struggled, in vain, in its first binds since the days of womb captivity. But it was of no use.
No amount of snarling and snapping at the bolas could break them as they were just out of its range of teeth. It wrestled around on the ground as dawn crept across the open landscape, when it was in mid-air the green floor below appeared like that of a filled canvass. It was gigantic, vast, and --- for a limited amount of time when seasonal passage permitted it--- a grand sight for it to behold. The dragon felt that it was the sole creature that would ever truly appreciate daytime.
Or, the Night Fury sympathetically thought to itself, the only who could appreciate daytime.
But now as its element slipped away, now as the creature of shadows felt its only cover being removed, it felt its fighting spirit die. What was the use? It wasn't going anywhere. The Night Fury watched calmly and quite blissfully as the rays of the shining life orb gathered to their full luminosity, and sighed heavily against its bounds. It was about to lie down and accept its fate with grace and dignity when a sound from up ahead made it go on alert. The Night Fury rolled its head up and emitted a warning hiss. As the noise drew nearer, it once again began to fight.
Morning burst fully into its fiery orange-red bloom, and the Night Fury thrashed around to try and get away. If it was going to die, it was going to be with its noble, stealthy pedigree intact and not as some trophy mounted up on a ground bird's wooden nest. It was almost to some nearby bushes, it was almost in reach of some wonderful if only meager coverage, when the Night Fury heard the same footsteps made by the ground bird that had shot it down. It pulled its lips back into a flustered, toothy grimace, and crushed its head into the ground. The stupid ground bird had sounded clumsy and uneven in its steps; as if it had not been taught by its own.
The dragon, itself, had trained many yearlings in its younger days.
It shook its head slightly and laid down in wait for the inexperienced Viking to make his arrival. The noises the creature made were indistinguishable at first and then went into a full, final-like shuffle as he jumped out from behind a boulder and held out a shining talon before himself. It, the suddenly very patient Night Fury, kept stone still and awaited for the more then obviously nervous ground bird's approach. Somehow, a sort of pity was growing inside of its chest at the desperate and very dangerous lengths the ground bird was taking to capture it. But why? Could the yearling not accept its place amongst its own kind? The ground bird, the Night Fury had seen many times, was a weapons crafter. His body was just not big nor fast enough to battle.
But still the ground bird approached it, and though the Night Fury held a respect for the other ones that put up a fight against its kind, it could simply not allow such a weakling, such a meek little rebel of a ground bird to embarrass himself like this; or allow itself to be slain by such an unworthy creature. It stared up at its trembling quarry. The creature uttered words that were meant to be taken for bravery, but the Night Fury knew it could not allow this young creature to mistake courage for a coward's kill. And that's what was happening. If the ground bird were to slay the Night Fury in its defenseless state, what kind of life lesson would the Night Fury be teaching its inexperienced rival? So it stared at him; its eye piercing insanely as the blinding sun.
The ground bird looked down at it uneasily. They both stayed in an unnatural eye engagement for the longest time. Finally, though, the ground bird relented. The Night Fury eased off a little as its message seemed to come through. But just as quickly, the ground bird surprised it now by raising his arms in the air with the shining talon posed up and ready to strike. Recognizing that this was its own method of attack, the Night Fury closed its eye and braced for the dive bomb.
Then, even more shockingly, the stupid yearling was impulsively and frantically cutting into all of the bolas binds. The Night Fury watched in intense incoherence as the ground bird relieved it of its shackles. He was grinning nervously now, probably expecting the Night Fury to be friendly.
Angered at the child's senselessness, it struck him down against the same rock that he had hid behind and bore a reprimanding glare into the ground's bird's eyes. The small weapon now fell uselessly from his featherless appendage and hit the ground soundlessly. The Night Fury felt the rage of the ground bird's carelessness overcome it and was about to smack him across the face to teach him his lesson when the ground bird sized him up, without a hint of pleading in his jade eyes, and cringed away in preparation for his fate. The Night Fury felt itself soften a little as the ground bird turned slowly and reflected in its mellowing yellow eyes. He looked at himself just as if he were seeing himself for the first time; and the dragon realized that their roles had changed.
They were not mere predator and prey. But, more importantly, were creatures of understanding.
It gave the ground bird one final hiss and then took off in flight. There was no way; the Night Fury thought to itself, there was no way that they were the same. But looking back over its slick black shoulder, and experiencing unease, it realized that there was similarity between the two.
There was empathy.
To be continued...