according to University of California-Davis Veterinary Care Program


Physical Characteristics (4-6 weeks of age)
      
      a. Comb – The cockerels comb is medium size and pinkish, the pullets
          is small and yellowish.

      b. Legs – The cockerel’s legs are sturdy and long, the pullets are finer
          and shorter.

      c. Tail – The cockerel’s tail is stumpy and curved, the pullets is longer
          and straight.

      d. Back – The cockerel has a thin line of stub feathers down the center of
          his back, the pullet has more advanced feathering along the center
          of her back.

      e. Side of neck, flank and crop – The feathering in the cockerel in these
          areas is poorly advanced, the pullets feathering in these areas is well  
          advanced.

      f.  Wing bows – In the cockerel the wing bows are bare, in pullets the
          wing bows are covered with small feathers.
HOW TO TELL
Is this a Rooster or Pullet?