Moreau R.E., Oerrins M. & Hughes J.T. (1969) Tongues of the Zosteropidae (white-eyes). ARDEA 57 (1-2): 29-47

Published statements regarding the tongues of the Zosteropidae, based on uncritical examination of a very small proportion of the described species, are conflicting and otherwise unsatisfactory. Examination of a wider range of material leads to the conclusion that the tongues are quadrifid and are fimbriated both at the sides and at the tip, but that any tendency to tubulation is an artefact. A survey of feeding habits, which are very imperfectly documented, suggests that in general nectar is by no means a main component of the diet of the Zosteropidae. Yet prima facie the anatomy of the tongue is adapted to its taking. The evolutionary problem is discussed in relation to other nectivorous families.