What characteristic is typical of birds with a rose comb?

Birds with a rose comb are recognized for their distinct flat, rounded shape. This type of comb sits closely to the head and appears smooth, lacking the prominent spikes or height found in combs like the single or V-comb. The flat nature of the rose comb helps it stand out among other comb types and provides certain advantages, such as protection against frostbite in cold weather. Other forms of combs, such as the large, bulbous appearance or the multiple tiers described in some options, belong to different breeds and do not characterize the rose comb effectively. Focusing on the shape helps in identifying birds accurately within poultry showing contexts.