In adult cockatiels, gender is relatively apparent on sight. Males usually have bright yellow faces with bright orange cheek patches, while female coloring appears muted, with gray or brown faces and duller cheek patches. Until after their first molting at 6 to 9 months of age, however, young male cockatiels look much like the females. Still, behavior will often point to one gender or the other. Male cockatiels vocalize and interact with toys, people and other birds differently than females do.
Only the rare female will talk or mimic, while the male will begin whistling and singing at 4 to 6 months of age and may even be able to "wolf whistle" before it is old enough to adopt. Female songs and chirps generally do not vary much, while the male can be a noisy bird, experimenting with different sounds and tunes. However, the female is more prone to hissing or biting.
Toys and Mirrors
Place a mirror in front of a cockatiel of undetermined gender. Usually, the male will be fascinated -- preening and posing in front of it, often at great length -- while the female will show little or no interest in her reflection. The male will also tap on dishes, toys and cage bars to engage a female's attention.
Female cockatiels are generally docile creatures, while males engage in dominant behaviors and ones expressing ownership. When a familiar human approaches the cage, the female cockatiel may simply wait for petting and attention. A male cockatiel will more likely seek out the attention and may be more interested in pecking at a person's mouth in attempt to learn or mimic whistles, than in inviting simple shows of affection. Males like to strut around with their chests puffed out and their wings lifted, so the wings appear heart-shaped from behind. They also engage in "beak-banging," an expression of ownership where they hammer their beaks on objects or even people.
When interested in mating, the male will sometimes rub his vent against perches and other objects while swishing his tail from side to side. Females will duck their heads forward, lift their tails and make soft chirping sounds. Sometimes the female will duck her back under a toy as if it were a male -- and may soon thereafter lay an egg, even if a male is not present.