Question: at what age can you tell the difference between a hen and a rooster?
Answer: When sexing most juveniles, the best, most fail-safe method is to look at the saddle feathers in front of the tail when the bird is about 3 months old. By that age, cockerels will have long and pointy saddle feathers, while a hen's will be rounded. Take a look at this rooster's saddle feathers.