Hello dear readers, you have come across a Jungle Phoenix Udyr guide. I am GodOfMayhem and I have been playing League of Legends for 1 year now. I play on the EU West servers and currently have an ELO of 1400. I have made jungling my specialty but I am by no means a professional player. In this guide I will try to explain what I believe is the most efficient way to play Jungle Udyr at my level. Constructive critisism is greatly appreciated as this is my first guide ever. Please forgive me if my English isn't perfect because English is not my native language. Now sit back and enjoy reading!

Smite: As a jungler you will absolutely need Smite to secure/steal buffs, dragons and barons. Furthermore Smite will increase the speed with which you jungle in the beginning.
Flash: Even after the recent nerfs to Flash I still prefer this summoner spell over Ghost. This is because as a jungler your strongest asset is the element of suprise, I believe Flash complements this better than Ghost. Besides this, Ghost becomes less effective as the game progesses because you keep getting a higher movement speed (way higher than other characters) and because of dimishing return Ghost becomes way less effective.

Greater Mark of Attack Speed: The damage of Phoenix Udyr scales best with attack speed because every 3rd attack Wingborne Storm deals massive damage hence we pick these marks. There are no other alternatives as near as good as these runes. The damage from Wingborne Storm is magic so the only possible alternative are greater marks of insight.
greater seal of vitality: I find these runes to be optimal for Udyr for several reasons. greater seal of vitality combined with the defensive masteries giving you extra health make you have a good sized healthpool without too much health items. Udyr also doesn't need the extra armor from Greater Seal of Armor in the beginning so it is better to aim for lategame stats.
Greater Glyph of Scaling Magic Resist: These runes are pretty standard, they will help you versus the enemies AP carry in teamfight later on. Greater Glyph of Scaling Magic Resist combined with Mercury's Treads and Wit's End will get you to about 150-160 magic resistance at lvl 18.
Greater Quintessence of Movement Speed: Udyr does not have any gap closers or ranged skills. The only way to solve this problem is to get a high movement speed. Greater Quintessence of Movement Speed along with the 2 movement speed masteries in defense and utility we get a high enough movement speed to partially cover Udyr main weak point, mediocre ganks.