Some cockatiels, usually males, will bang their beaks against things, such as counter tops and cages. The idea is to be noticed, usually by whatever or whoever has become their love interest.  Cockatiels can fall in love with objects, their own reflection, other birds, and even you. He may also whistle or lean towards the person or item. Hopping is similar to beak banging; he's looking for attention. However, hopping is taking it to the next level from beak banging. He's really begging for attention. Sometimes, in coordination with other behaviors, cockatiels will make loud squawking or screaming noises. Basically, the cockatiel is looking for attention. Head snaking is when the bird moves his head from side to side. It's a fluid motion, not jerking. Usually, the bird is just asking to be noticed. When a cockatiel is trying to attract a mate, he may let the feathers on the top of his head curl up into a crest. Basically, it creates a little curlicue on the top of his head. However, he could also be defending his territory with this gesture. Another sign of seduction is the fanning of the tail feathers, paired with the cresting of the head feathers and the spreading out the wings. He may also strut around and whistle. Again, this gesture could also be a sign he's defending his territory.

How would you rephrase that briefly using Vietnamese?
Quan sát động tác đập mỏ. Quan sát động tác nhảy. Lắng nghe tiếng kêu to. Chú ý đến động tác lắc lư đầu. Tìm chòm lông mào trên đầu. Quan sát lông đuôi và lông cánh.