I have six 5 week old chicks. Four have tails shaped like praying hands- long and V-shaped. Then I have an EE with a short tail, but s/he doesn't stand upright like a rooster might- she's kind of barrel shaped lol. Then I have a Barred Rock that I go back and forth on. S/he stands more upright, and developed a comb earlier, and has shorter tail feathers too. But the comb isn't really getting any redder yet- sort of a fleshy pinky color. S/he also has been the last to lose the neck feathers. But the Barred Rock isn't as light as most roo's are at five weeks. I will have to post some photos. But my main ? is whether or not you can always tell by the tail?