[6] Although honeyeaters look and behave very much like other nectar-feeding passerines around the world (such as the sunbirds and flowerpeckers), they are unrelated, and the similarities are the consequence of convergent evolution.

Many genera have a highly developed brush-tipped tongue, frayed and fringed with bristles which soak up liquids readily.

The tongue is flicked rapidly and repeatedly into a flower, the upper mandible then compressing any liquid out when the bill is closed.

In general, the honeyeaters with long, fine bills are more nectarivorous, the shorter-billed species less so, but even specialised nectar eaters like the spinebills take extra insects to add protein to their diet when breeding.

Fluctuations in local abundance are common, but the small number of definitely migratory honeyeater species aside, the reasons are yet to be discovered.

The genus Notiomystis (New Zealand stitchbird), formerly classified in the Meliphagidae, has recently been removed to the newly erected Notiomystidae of which it is the only member.

The wattled smoky honeyeater (Melipotes carolae), described in 2007, had been discovered in December 2005 in the Foja Mountains of Papua, Indonesia.