Cockatiels (Nymphicus hollandicus) also exhibit color differences, with males displaying a much brighter yellow head and orange cheek patch and females having more yellow on the tail. In addition, all ...

In other hand, cockatiels (Nymphicus hollandicus) and ring necks (Psittacula krameri), were the most researched birds, with infection rate of 20% (40/50) and 100% (6/6), respectively. A high ...