The Yellow Plumed Honeyeater is similar in size to the White Plumed Honeyeater and the Fuscous Honeyeater. At times, it can be difficult to tell the difference between the Yellow Plumed Honeyeater and the Fuscous Honeyeater. All three birds inhabit similar type environments and you will see them particularly around dams. They even mix and drink with each other as well.
The main difference between the Yellow Plumed and the Fuscous Honeyeaters is that the plume on the Fuscous is smaller. The Yellow Plumed tends to be more heavily streaked on its chest, whereas the Fuscous is more plain.
Wikipedia has very little information on these birds.