Can someone please help me identify the most likely gender of my 2 year 3 month old pearl cockatiel? Their name is Sunny! Sunny arrived at my home 2 days ago but the previous parent did not know the gender. I have a gray cockatiel, and his name is Petrie and he is very much a male. Their behavior is different, but I do not know if this is due to Sunny being in the new environment.