1. Size: Male tufted titmice are typically slightly larger than females, with a longer tail and a larger head.
2. Coloration: The male tufted titmouse has a brighter, more vibrant coloration than the female. The male's head is black, while the female's is a dull gray. The male's back is a brighter blue, while the female's is a duller gray-blue. The male's flanks are also a brighter rusty color than the female's.
3. Behavior: Male tufted titmice are more likely to sing and display than females. They are also more likely to be aggressive towards other males.
4. Genetics: The gender of a tufted titmouse can also be determined by genetics. Male tufted titmice have two Z chromosomes, while female tufted titmice have one Z chromosome and one W chromosome.
By combining these methods, you can accurately tell the gender of a tufted titmouse.