The Aru Eclectus Parrot is a large Eclectus parrot rivaling that of the Vosmaeri Eclectus. Some individual males have the appearance of being larger than the Vosmaeri but this is because of its length. The Vosmaeri is a more bulky bird than the Aru Eclectus. The main difference between the Aru Eclectus and all other Eclectus is that it is long and narrow in body structure. What gives this subspecies this lanky appearance is that it has a much longer tail than that of the Red-sided. In fact, the Aru Eclectus has the greatest length of tail in comparison to its size than that of any other Eclectus subspecies. Even though the Macgillivary’s Eclectus is much larger, it does not have the proportionately long tail of the Aru Eclectus. The streamlined, narrow look to this subspecies is also evident in its lanky neck.
The Aru Eclectus male is very similar in coloration to the Red-sided except that it has a slightly lighter plumage. Its most definitive difference is the broad edging to its long tail. It has a broad (.6 inches), well-defined lemon yellow edging to its tail. His iris is bright fiery red in color.
The Aru female is similar in coloration to the Red-sided female except that it has a slightly lighter body plumage. It is also a larger subspecies than the Red-sided. The long tail of the Aru Eclectus female has less extensive black at the base of its light red tail. The edging of its tail often shows an orange-yellow sheen on some individuals.