[Ollie and CJ]

Hi all, so i bought my daughter a pair of 18mth old hand raised cockatiels for her birthday. They are both supposedly male, and a bonded pair which i believe as they are never more than a meter or 2 apart. Occasionally it appers that the yellow one (Ollie) is bullying the white one (CJ). It happens out of no where, isnt over food, water or perch space as Ollie will "hunt down" CJ even outside the cage. It starts with Ollie making a specific high pitched call over and over then he goes at CJ. Its nothing severe, just pecking and leg biting which CJ doesnt really react to. Is it something I should be worried about or is this a natural dominance display?
Ollie and CJ -youtube video of the behaviour.

 

[MxAether]

Interested on input on this! My two boys who have been together for nearly 10 months now and rarely are out of each other’s sight have been having escalating fights! I do everything I can to reduce hormones, but it’s like WWE in there!