They run away at deep yellow health. They can retarget and move items that are in their way, though they themselves cannot be pushed. Their drunkenness is very heavy, but lasts for short time. They are often found in packs.
Some scholars consider the Wyvern a distant cousin of the Dragon, though this is far from truth. The Wyvern we know today is the result of constant breeding of some significantly smaller, only mildly poisonous flying Lizards.
Chyllfroest: Several on top of the mountain and underground.
Knights can kill a Wyvern around level 30 with skills between 65/65 and 75/75, depending on the equipment worn and fighting stance. For blocking, 60/60 would be enough. Level matters more than skills because of their poison attack. Stay diagonal to avoid the poison and musical waves. Avoid wasting Energy Fields because it's likely you'll kill them fast enough without them, and you could step on your own field while moving around.
Paladins can hunt Wyverns at level 23 with 40 distance (60 is recommended), shooting Arrows, Royal Spears or Bolts while trying to avoid Poison Wave. If poisoned, use Cure Poison as soon as possible to keep your health from being drained (it's quite likely you'll receive no other damage). You should consider wearing a Dwarven Ring, because if you become drunk and can't run away you'll be receiving melee damage. Fighting Wyverns at low level and about 55 distance is one of the fastest and safest ways a paladin can level because they give good experience. As a guide, the best place for a lower level paladin to solo Wyverns is in the field north of the Edron Dragon Lair. There are two spawns total and plenty of room to run them. A level 30 paladin with 60 distance using a standard Bow can expect to kill, on average, 1 wyvern for every 20 Arrows shot. Start at the north and draw the Wyvern southward as you shoot. Because there is so much room to maneuver, you can easily avoid the poison wave. The musical wave is even simpler to stay away from, as it doesn't project very far. As described here, a paladin can kill a wyvern without taking any damage. Accordingly, in this locale, a Dwarven Ring is not really necessary. While waiting for respawn, make sure you kill the Poachers in the northeast woods as they routinely drop arrows, which helps to keep your ammo stocked. Mages can kill them easily around level 27 with Flame Strikes or Fireballs. Lower level spell casters can shoot Fire Field runes to "soften it up" and help kill the Wyvern faster. Heal with Intense Healing and consider using Magic Shield. Mages often summon Demon Skeletons or Monks to kill Wyverns while shooting with an appropriate Rod or Wand, depending on their level and vocation. Using Death Strikes is also a consideration.
Hunting in a team: Depending on your vocation and how much room you have, using a Silver Amulet and a Dwarven Ring is a good idea to reduce poison damage and prevent becoming drunk. You can hunt these with a low level team, consisting of a blocker (lvl 25+) and a shooter. Another way to hunt these creatures is to get a group of 3 or 4 people and go to a single spawn, like the one near Venore. Simply have the strongest go up first, followed by the others. Each person should be level 15+ or they will die. Lure the creature to a spot where everyone can stand diagonally. Make sure each of you have Light Healing or Intense Healing and Cure Poison, or its poison will kill you. Just attack until it runs away, and make sure you stand at a good angle where the poison wave won't affect you.